Volume 2 of the USAF investigation of the
for HIRF information.
24 March 1998
Source: Hardcopy The New York Review of Books, April 9, 1998, pp.
59-76
Thanks to Elaine Scarry and NYRB
Special Supplement
The Fall of TWA 800:
The Possibility of Electromagnetic Interference
By Elaine Scarry
| Elaine Scarry teaches at Harvard University, where she is Cabot Professor of Aesthetics and the General Theory of Value. Her writings include The Body in Pain and articles on war and the social contract. |
Reconstructing the wreckage of TWA 800 in a Long island hangar, November,
1997.
The piles of wire visible in the foreground are only a part of the plane's
150 miles of wiring.
For more than a year, the inquiry into the fall of TWA 800 has addressed three questions: whether mechanical trouble can be ruled out, whether a bomb inside the plane can be ruled out. whether a missile or other high-velocity object (such as a meteorite) can be ruled out. But there is a fourth possibility that has been ignored and that needs to be raised in the inquiry.
To a civilian, the phrase "electromagnetic interference" may at first sound
puzzling, even though every commercial flight begins with the instruction
to passengers to turn off during takeoff all computers, headsets, radios,
and telephones. The power radiated by these objects is tiny. But their emissions
can travel out of the cabin windows to the antennas on the outer body of
the plane; therefore the FAA regulation requiring airlines to prohibit passenger
use of such objects has remained firmly in
place.1 Interference from military equipment
can be thousands, even millions, of times as
great,2 and can have much more serious consequences
for airborne planes. Because ten military planes and ships were in the vicinity
of TWA 800 that night, we need to ask the airmen and sailors on the planes
and ships to describe with precision the pieces of equipment that were in
use.
HOW REAL IS THE PROBLEM
OF HIGH INTENSITY RADIATED
FIELDS?
Electromagnetic interference may come from inside the plane or from outside it. What makes the internal sources a matter for concern is that they are so close to the systems they might affect; what makes the external sources a matter for concern is that, despite their distance, their power level can be very high. Although the internal and external overlap in their effects (see box), in general the external sources involve much higher power levels, even after traveling some distance; hence they may have more serious effects. Called HIRFs -- which sometimes stands for High Intensity Radiated Fields and other times High Intensity Radio Frequency -- the external signals come either from huge ground transmitters such as radio, radar, and television antennas, or airborne transmitters such as high-powered radar and radio on military planes.
The distinction between "ground" and "airborne" transmitters is sometimes instead referred to as a distinction between "fixed" and "intermittent" transmitters, words that somewhat obscure the possible effects of military equipment but have the advantage of making clear why the airborne sources of HlRFs may be harder for pilots to avoid. Because a ground transmitter is "fixed," its location is marked on most aviation maps and can be avoided by the pilot. If a pilot on a particular flight has an electrical problem and, upon reviewing it, discovers the plane was at that moment flying in the area of a powerful ground transmitter, there is a possible concrete cause to investigate. An airborne, intermittent transmitter, in contrast, cannot be as easily avoided; nor, if an anomalous electrical situation emerges, is there usually any way to know what military craft were nearby and what particular transmitters were in use.3
Beginning in 1989, the FAA started requiring the aviation industry to increase its attention to the problem of HIRFs and to place higher levels of shielding on planes. Some members of the aviation industry, such as Monte Mitchell, executive director of Aircraft Electronics Association, were upset, not just because they had not been consulted and would now encounter larger costs, but because the problem was being described as "a grievous hazard" without any actual facts being given. Furthermore, the requirements for increased shielding were only being applied to new planes, not to those already in the air. "Does HIRF represent a dire and immediate threat to civil aircraft operating in the nation's air space?" Mitchell asked, calling attention to the FAA's failure to cite any accidents or to ground any untested airplanes already flying. If it does, he continued, "then the FAA is guilty of malfeasance in not grounding the entire civilian fleet before lives are unnecessarily lost to this environmental threat."4
This past summer, the FAA issued a Flight Standards Bulletin about the problem of High Intensity Radiated Fields. The policy statement couples HIRFs (electromagnetic interference originating from sources outside the passenger plane) with lightning (which is itself a powerful electromagnetic event).5 This coupling suggests the seriousness with which HIRFs are regarded: the bulletin explicitly notes that electromagnetic interference from electronic devices carried by passengers-- which is much weaker -- is dealt with in a wholly separate policy statement. Although the bulletin specifies the source of HIRFs as radar, radio, and television transmitters, it does not mention the military. But a 1994 NASA study does. It notes that "the cause of High Intensity Radiated Field events may often be inadvertent effects on civilian aircraft of high-powered military operations or covert drug interdiction"; it specifies that military jammers and electronic countermeasures equipment can affect key systems on commercial planes flying through the same geography; and it observes that the problem turns up most frequently in regions such as the Caribbean where there is "a large amount of American shipboard and airborne surveillance."6
The NASA study makes it clear that this kind of electromagnetic interference can lead not just to disruptions in airplane navigation and communication systems but to "loss of aircraft and life." A false reading on an instrument may itself have dire consequences if a pilot is approaching a runway in a difficult terrain or a crowded urban area. But electromagnetic interference may also introduce a false command into the plane's electrical system, suddenly instructing its rudder to move, or (at higher power levels) disrupting a plane's control surfaces -- its rudder and wing flaps -- by burning out a circuit. Military planes may themselves at times become vulnerable to interference from other military craft.
A seven-month-long Air Force study concluded in late 1988 that "thousands of conflicts" among radio waves used by the three branches of the military had produced grave outcomes. Electromagnetic interference can jam equipment, burn out electric circuits, and even prompt explosions (as when, driving near a blasting area, one is instructed to turn off a car radio). According to Colonel Charles Quisenberry. the director of the study, it can also " 'affect the electrons within the aircraft's flight controls as well as its fuel controls,' . . . putting a plane into an uncommanded turn or dive or turning off its fuel supply."7 Some forms of interference, Colonel Quisenberry stated, "are very, very critical -- some cause aircraft to crash."8
Although most concrete instances remain classified, Colonel Quisenberry specified two. Because of electromagnetic interference, Black Hawk helicopters have periodically crashed and killed their crews. The crashes appear to have occurred five times in the six years between 1982 and 1988, with twenty-two deaths. "The Black Hawk was shielded at a very low level -- it was known ahead of time that its shielding was inadequate," Colonel Quisenberry stated.9 (Even before the Air Force study, one senior Army aviator had gone on public record about the Black Hawks: "EMI is causing these aircraft to flip upside down and crash and kill everybody aboard.''10) The aircraft called F111s have also been extremely vulnerable. One fell near Libya in 1986, killing two airmen; five other F111s were disabled during the same mission. Colonel Quisenberry reported that electromagnetic interference was a possible cause of the F111s' problems.11
How serious is electromagnetic interference in the eyes of the military? So serious that attempts to address the problem have for years been evident throughout the construction of their planes, ships, and ground vehicles. The choice of outer materials is shaped by concerns about incoming signals. Navy planes that land on carriers are built to withstand high-electromagnetic fields.12 If the outer shell of a plane proves insufficient, new layers will be added: extra shielding costing $175 million now covers the flight control computers on the Black Hawks.13
The attempt to remedy the problem is visible, too, in the addition of electric filters. While planes and ships may have accidental emissions of electromagnetic waves, at least one plane in each branch of the military has been explicitly designed to bring about dire outcomes through radar and pulses: the Navy Prowler (based at Whidbey Island, Washington), the Air Force Compass Call (based at Wright-Patterson in Ohio), and the Army Common Sensor (based at Vint Farms, Virginia). The problem is how to damage the sensing and signaling capacities of the enemy's plane without damaging similar capacities on your comrade's plane. In 1993, Congress authorized special funding for a series of high-frequency and very-low-frequency electric filters to be fitted onto Common Sensor and Compass Call by 1998. The purpose of the filter, as it is phrased in electronic warfare literature, is to "reduce fratricide.''14 The Navy Prowler, at one point also scheduled for an upgrade, has not yet received it even though its tactical jamming system is on record as straying toward civilian planes or ships.15
Efforts to control incoming and outgoing signals often determine the architecture of military craft. The cruisers and destroyers with Aegis equipment for guided missiles -- called Aegis Guided Missile Cruisers and Destroyers -- form the backbone of the country's surface fleet since they are responsible for defending the large carriers. The Aegis-equipped ships built during the 1980s are in the class called Ticonderoga CG-47: both the USS Vincennes (which accidentally shot down an Iranian Airbus in 1988) and the USS Normandy (applauded for its actions in Bosnia in September 199516 but later a source of concern to the public when it turned up in the vicinity of TWA 800) belong to this class. Starting in the late 1980s and continuing into the 1990s, the CG-47 has been replaced by a class of destroyer called DG-51 Arleigh Burke: its key difference from its predecessor with respect to its Aegis equipment is that its Combat Information Center has been placed "below the waterline [where] all electronics are hardened against electromagnetic pulse."17
The attempt to avoid electromagnetic interference, finally, not only has a pervasive effect on the choice of materials and the shape of aircraft but has even begun to prompt a systemwide reform: the shift from "fly-by-wire" to "fly-by-light" -- from electric wiring to fiber optics (which operate by encoding data inside light beams confined within transparent fibers that guide them to their destination). Why are NASA. the Department of Defense, McDonnell Douglas, Allied Signal, Honeywell, Raytheon, Lear Astronics, and so many other companies engaging in fiber optics research despite the staggering labor in making the sweeping, countrywide changes that a conversion to fiber optics would involve? The answers they give are straightforward. Fiber optics (among many other virtues such as their light weight and their capacity to carry large amounts of data rapidly) are immune to electromagnetic interference.18 As Raytheon President and former Aircraft Chairman Arthur Wegner observed, fly-by-light will eliminate "problems with high-intensity radiated fields . . . . that have plagued designers of fly-by-wire systems, and 'brought a few of their airplanes out of the sky.' "19
The introduction of new shielding, new shapes, and new systems designed to protect a craft from fraternal emissions will also, of course, help to protect that craft against enemy emissions should the United States enter into combat with foreign forces.20 Inadvertent interference from a fellow plane may serve (assuming one survives the encounter) as an early warning, calling attention to a path of electronic vulnerability that might later, be intentionally pursued by an enemy jammer or microwave weapon. But the particular focus here has been on problems accidentally inflicted on our military craft by their own companions (cases in which, to use Colonel Quisenberry's language, "We did it to ourselves"21) and on those repairs whose lineage can be traced back to an incident of electromagnetic interference by US equipment.22 It is hard to comprehend why High Intensity Radiated Fields should be of sustained concern to the military and yet not be even a subject of discussion when a civilian plane goes down. It is certainly true that military planes spend more time in the company of other military craft than do civilian planes (and greater exposure time increases the chance that one day a stray emission may accidentally imperil them). But it is also true that civilian planes do sometimes (as in the case of TWA 800) end up in the vicinity of military craft. That many hundreds of thousands of plane flights take place without incident should not deter inquiry into the accumulated evidence of the dangers that may result from electronic military transmissions.23
In military and scientific research, the phrase "electromagnetic compatibility" is used almost interchangeably with the phrase "electromagnetic interference" since the two are mirror terms: the first expresses the aspiration to control or eliminate the problems expressed by the second. Since 1961, the Pentagon has had a 600-person agency located in Annapolis called the ECAC, Electromagnetic Compatibility Analysis Center, a reminder that the problem of electromagnetic inconsistency (which may seem insubstantial because seldom spoken about aloud) is real enough to warrant the spending of substantial public money.24 Another division of the Pentagon is called the Joint Electronic Warfare Center. Even equipment that is designed to bring about intentional interference can have unintended effects. In response to the Air Force's 1988 study of the way radio waves have jeopardized airborne craft, the Pentagon initiated a $35 million three-year-long investigation,25 whose results have never been made public. American citizens need to request that this Pentagon study, as well as the earlier Air Force study, be either opened for the public record or, at the very least, made fully available to all those charged with investigating TWA 800 and other inexplicable falls from the sky, such as USAir 427 that in 1994 went down near Pittsburgh, and the 737 that went down over Colorado Springs in 1989.26 American citizens who paid for these studies -- and for the Black Hawk computer shielding, the redesign of the Aegis, the research on fiber optics -- need now to be made the beneficiaries of this research.
The idea that citizens should benefit from the scientific research they fund is a principle with many applications. During the week-long public hearing about TWA 800 in Baltimore this past December, Jim Hall, the chair of the National Transportation Safety Board, raised the point repeatedly, returning to it whenever it became clear that research successfully completed on behalf of military aviation had somehow never reached the agencies responsible for civilian aviation.27 Unshared military research on wiring, fuel gauge residues, and bonding inside central fuel tanks prompted Hall's patiently repeated queries. But the need for open information is even more pressing in the case of electromagnetic interference -- a subject not yet investigated by the NTSB -- because the phenomenon involves computations whose difficulty is likely to seem overwhelming not just to a population hearing about them for the first time but, as will be suggested below, even to researchers who have dedicated many years to solving them.
We do not at present have a picture -- a background -- against which to see, or even think about, the part that might have been played by electromagnetic interference in the fall of TWA 800. Yet that background picture exists. It exists in the physical examples collected in the seven-month-long 1988 Air Force study and the empirical evidence gathered in the three-year-long 1989-1991 Pentagon studies. (The request for this information leaves to the side the vast amount of military research undertaken for electronic warfare that analyzes intentional interference precisely calibrated to interrupt the electronic equipment of an opponent,28 as well as research carried out to test the survivability of our own craft to willful electronic disruption by an enemy.) What the Air Force and Pentagon studies of inadvertent interference will provide is concrete examples of power levels, distances, and forms of equipment that have caused crashes: the power level and distance of the transmission source that, for example, caused Black Hawk helicopters to "flip upside down"29; these may vary greatly from crash to crash and may in turn collectively be very different from the power level and distance ,of the Navy jamming equipment that may have caused the F111 to crash; in turn, a different set of power levels and distances may be involved in the many cases Colonel Quisenberry alluded to but could not voice.
With the help of such information, a clear account of the physical features of electromagnetic accidents will begin to come into view: the cases in which all electronic systems cease simultaneously; the cases in which a black box ceases to record; the cases in which, either as an early or a late incident in the accident, a craft explodes before hitting the ground (as the F111 in the Libya mission eventually exploded into "a fiery ball" before, like TWA 800, disappearing into the sea). At present, there exist in the public domain only two kinds of information. The open literature occasionally provides clear statements about power levels and distances (a rare example is a book by Clayborne Taylor and D. V. Giri, High-Power Microwave Systems and Effects, that describes both truck-mounted and ship-mounted systems; it gives the radiated power as it moves from the site of transmission to distances ranging from 100 meters to 32 kilometers30); but this literature does not specify equipment by name or identifying number that enables one to know where, or even whether, it is currently in use.
Conversely, we have concrete information about equipment now in use, with only the haziest information about power levels and distances: the Sea Hawk helicopter (the Navy version of the Black Hawk) received shielding long before the Black Hawk, and until that shielding was added, pilots were under strict instructions to stay "some significant number of miles" from transmission sources.31 This information is helpful since it specifies that electromagnetic interference takes place at distances measured in miles (rather than, for example, "some significant number of feet"), but the number of miles is classified.
[Image omitted]
P3 Orion
It may fairly be objected that the 150 miles of wiring inside TWA
80032 bears little resemblance to the wiring
arrangements inside an F111 or an Army helicopter. (We know, for example,
that the interference effects from a given electromagnetic event can vary
greatly from aircraft to aircraft.) But if this is so, then there is reason
to request that the military provide information about those plane models
closest to TWA 800, which was a Boeing 747-100. The two planes that together
make up Air Force One are 747-200s; and the four planes that make up the
country's E-4 Command Post Aircraft are also
747-200S.33
The choice of this plane for presidential and command-post use suggests the sturdiness and reliability of the 747. At the same time, Air Force One is openly acknowledged to have been carefully shielded against electromagnetic pulses and it is almost unimaginable that the Command Post Aircraft have not been similarly shielded. Is it just the cockpit controls that are shielded? Or is it the cargo door opening? the windows? the rivet joints? the gaskets? the door to the landing gear? Tests conducted on these planes. during the period their layered shielding was being engineered may suggest the paths of interference that most need to be explored in the case of TWA 800 (and conversely, research undertaken on behalf of TWA 800 may one day make Air Force One and our fleet of E-4s more immune to both intentional and unintentional electromagnetic insults). No one should believe that the research required to determine how a particular path of interference took place will be easy. Carl E. Baum, Senior Scientist at Phillips Laboratory and the recipient of many prizes for his work on electromagnetics, describes the difficulty of calculating the electromagnetic interaction between two electronic systems:
It is hard enough to calculate the fields on the exterior of a complex system such as a ship, missile, aircraft, tank, etc. . . . As one goes to the interior and encounters thousands of wires going to numerous black boxes, antennas, etc., through various cavities and other strange structures the calculation problem gets quickly intractable. Even if one thought he could calculate such a complex problem, he would likely miss important signals because the system in the field is often different from the drawings by various changes for the convenience of the operators.34
In the 1970s, Baum invented a mathematical modeling procedure for solving problems of electromagnetic interference that is now used both nationally35 and internationally.36 It provides a computational method. for moving through the "nested" series of shielding layers that alternate with spatial volumes inside an aircraft. Yet Carl Baum himself stresses the importance of using realistic physical evidence, rather than abstract mathematical calculations, wherever that physical evidence is available. Radiating an aircraft on the ground with a blast of power is a start, but it is one-dimensional, incomplete, and crude. Baum refers to the procedure as an "electromagnetic hammer":
What does this accomplish? . . . One might discover one or more significant interaction paths into the system. . . . However, how does one know if all the relevant interaction paths have been discovered? Furthermore, are all the signal strengths that may cause failure in the system as large as they would be in the real environment? There are so many potential signals of interest (voltages/ currents at ports into electronic boxes/circuits) that for complex electronic systems one can only measure a small fraction of these in a practical test."37
The concrete, empirical instances from the Air Force and Pentagon studies will begin to provide a background picture, a concrete background picture that is crucial if the inquiry is to go forward.
But a great deal of information will also have to be provided about the
foreground.
"IN THE VICINITY"
TWA 800 AND
ITS MILITARY NEIGHBORS
On the evening of July 17, 1996, TWA 800 had been directed onto, and was
traveling in, the "Betty Route," the route assigned to commercial planes
when parts of Long Island Sound, designated W-105 and W-106, are either in
use by the military or reserved for military use. In addition to the formal
record provided by the air controller's verbal direction, the FAA log books
also confirm that the military had that night reserved, though not necessarily
used, W-106 (sometimes pronounced Whiskey-106, sometimes
Warning-106).38 We do not know what level or
intensity of military exercises was underway that night. We do know military
craft were in the air and sea at the moment TWA 800 had reached 13,700 feet
and began to fall. Directly overhead was a Navy P3 Orion with its
transponder39 turned off: it was 6,300 feet
above the passenger plane and had intersected its longitude and latitude
within seconds of the moment the catastrophe began. In the airspace beneath
TWA 800 a Black Hawk helicopter and an HC-130 plane were flying at an altitude
of 3,000 feet: they were five miles north of the commercial liner. A Coast
Guard cutter rescue ship, the Adak, was somewhere on the sea below, its precise
location in relation to the falling plane unspecified in the official record
but given in news reports as nine to twelve miles south. One hundred and
eighty-five miles to the southwest was an Aegis cruiser, the USS
Normandy: that mileage places it off Maryland's Eastern
Shore.40
In addition to those five craft just named, five others were present, a fact first acknowledged in November 1996 by Rear Admiral Edward Kristensen who mentioned several military planes -- other than the P3-flying at altitudes above TWA 800 and one or more submarines eighty miles south, roughly midway between TWA 800 and the USS Normandy.41 These craft remained unnamed and uncounted until November 1997 when, announcing the withdrawal of the FBI from the investigation, Assistant Director James Kallstrom included in the final roll call of military craft one C-141 Starlifter cargo plane, one C-10 refueling plane, attack submarine USS Albuquerque, attack submarine USS Trepang, and Trident submarine USS Wyoming. Because we don't yet know the locations of these five (their altitude or depth, their distance and direction), the account that follows will focus only on the first five, which can serve as a sample of the questions that need to be asked of them all. What does it mean to say that one Orion, one Black Hawk, one Hercules C-130, one rescue ship, and one Aegis were "in the vicinity" of TWA 800? Together they formed a temporary envelope around the passenger plane: above it, below it, to the north of it, to the south of it. But the distances vary greatly. (See chart above.) The closest craft was directly overhead, separated by a distance measured as 6,300 feet. The farthest was 185 miles away. Should the Aegis even be included in an inquiry into HIRF accidents? There are four key reasons why it should, reasons that will be specified once the Aegis is examined in its turn. The account that follows makes no attempt to provide evidence that a HIRF accident brought down TWA 800. It instead provides evidence showing why a HIRF accident must be looked into, must be included among the subjects investigated by the National Transportation Safety Board. These planes and ships are not electromagnetically neutral. Moreover, simply to be in the air or out at sea requires that equipment be in use. The NTSB needs to ask: What equipment was switched on? What instruments were turned off? What was the sequence of those acts? We need to know the answers to these questions if we are to determine whether electromagnetic interference -- a sudden pulsing or spiking in the electronic environment -- may have caused TWA 800's electrical systems to go haywire, as is compatible with the fact that the transmissions from the transponder on its belly and the transmissions from the cockpit both ceased at the same moment, as did the black box (which often continues to record, even in the late stages of a plane's catastrophe).
If a sudden pulse or electromagnetic spike can short out a wire or (as Colonel Quisenberry said) by disrupting electronic circuits, simply cut off the fuel supply or make the flight controls on a plane go dead, isn't it relevant to determine the electromagnetic features of the air through which the plane aspired to fly that night?
P3 Orion. Flying at an altitude of 20,000 feet, the P3 Orion (according to Kallstrom42) crossed the path of TWA 800, either at the moment or shortly before the moment when its transponder and cockpit and black box went dead. The P3 Orion is a plane well known to the public since it frequently turned up in the news in the 1980s criticized for its $16,000 refrigerator and its $640 toilet seat. What the public may not have realized was how tired of the plane the Navy itself was. Year after year they petitioned Congress to stop authorizing more P3 Orions from Lockheed, but year after year more contracts got signed. The Navy's impatience with the P3s is relevant to the question at hand, for they had a specific, repeated complaint: the P3 Orion was "so loaded down with new equipment and avionics that it [could not] fly nearly as far or as long as it once did."43 By "equipment" the Navy did not mean helmets, rifles, tanks: the P3 is not a transport plane. They meant radar, radio, sonar. Originally scheduled to be replaced in the next century, the P3 has virtues that make it almost impossible to replace. It will therefore soon begin to appear in a new form, Orion 2000.44 Even now it exists in three forms: the standard, equipment-rich P3 often seen flying low over the ocean, tracking submarines and mapping the ocean floor; a P3 modified for intelligence missions called Reef Point P3B or P3C; and a P3 modified for electronic warfare called the EP3. Like the regular P3, the EP3 is stationed at Brunswick, Maine (the location from which the Orion flying near TWA 800 originated). The EP3 requires, in addition to the ten regular flight crew, an additional fifteen crew to operate the extra receivers, jammers, radar signal collectors, and infrared countermeasures system.
The verbal designation "P3" does not definitively tell us which form of the P3 crossed TWA 800's path. (An EP3 can, without falsification, be called a P3, so long as all other military planes in the area are similarly truncated down to a single-letter designation).45 Nor would a quick visual sighting have provided any help since the EP3 often imitates the P3. It is "painted... with spurious unit insignia and serials, and painted-on 'sonobuoy tubes,' "46 that associate it with the P3's central tasks of tracking submarines, mapping the ocean floors, and mapping the earth's magnetic field. The painted-on sonobuoy tubes, by being associated with the P3's daily routine, are designed to deflect the observer's interest. The EP3's aspiration to be mistaken for a P3 is part of its larger project of electronic signal collection and self-fictionalization, as is registered in the names of its various sensing and cryptology systems: Story Book, Story Teller, Story Classic. Admiral Kristensen has provided the public with useful information about the plane's activity on the evening of July 17, but even that does not help us to sort out whether the plane was a regular P3 or an EP3 or a Reef Point P3B/C. After crossing TWA 800's path, the plane flew to a submarine exercise area eighty miles south and dropped thirty-nine sonobuoys.47 This action is compatible with a P3's routine activity of dropping sonobuoys but it is also compatible with an EP3's routine activity of imitating a P3. (Whether it is compatible with the tasks performed by a Reef Point is unclear since none of the Reef Point's activities are described in the public record.) In leaving the crash site and proceeding on to the submarine exercise area, the P3 or EP3 or Reef Point was, we are told, apparently unaware of the TWA 800 catastrophe that was taking place in the airspace directly beneath it. (The hundreds of witnesses who did see a strange event in the sky from water, land, and air were in most instances located at much farther distances from the failing plane than was the one-mile-higher Navy plane, though perhaps its location directly overhead or its involvement in other tasks created a blind spot.) Fifteen minutes later, after arriving at the submarine area, the plane, according to Admiral Kristensen, learned about TWA 800 and turned back to see if it could help.
Although it is important to learn the precise form of the plane, it is conceivable that any one of the three could have inadvertently participated in a High Intensity Radiated Field incident; and the description that follows will concentrate exclusively on the regular P3. Flown by both reservists and elite Navy pilots, the regular P3s are versatile planes. Their work includes, at one end of the spectrum, daily state-of-the- art acts of tracking and mapping; and at the other end, what the military itself treats as breathtaking technological experiments. P3s, for example, participated in a series of "over-the-horizon" feats of targeting connected to a satellite system for Elint (or electronic intelligence). The names of the exercises and systems suggest their connection to radar, radio, and the reach (or radiating wave motion) of electromagnetic signals -- Radiant Oak, Radiant Ivory, Radiant Hail,48 Radiant Clear, Radiant Elm, Radiant White, Radiant Gold.49
The Navy exercise called Radiant Oak took place off the coast of Southern California on August 19, 1993. According to Aerospace Daily, a P3 Orion and an EA6P Prowler first "flew a 500-mile, low level ingress to the target area, remaining terrain masked from the threat."50 The exercise itself demonstrated that Orions and Prowlers can track, target, and destroy an object-- in this case a boat on the sea -- that is not within the horizon of their own radar. Using not pictures from its own radar but pictures relayed to its cockpit from satellites, the Prowler first destroyed the ship's radar by sending down a HARM missile (High Speed Anti-Radiation Missile). Then the P3 Orion, using the same over-the-horizon pictures, fired a Harpoon missile, destroying the ship itself.51 Of relevance to the particular issue raised in this article -- the appropriateness of including HIRFs in the TWA 800 inquiry -- is not the fact that the P3 sometimes fires missiles but the fact that the P3, though a sturdy workhorse, is often involved in complex experiments involving state-of-the-art electronics and sophisticated relaying of information to or from other craft. The P3 Orion is not involved in every over-the-horizon exercise. But often when a particular piece of equipment has to be airborne -- such as OASIS-III (Over-the-horizon Airborne Sensor Information System) -- it is designed to be installed in a P3C Orion.52 There is one other aircraft that is just as often called upon to carry highly sensitive instruments: the Black Hawk helicopter. A Black Hawk was north of TWA 800 the night it fell, not apparently on its way anywhere but simply in the air, getting ready to practice various rescue maneuvers.
[Image omitted]
Black Hawk helicopter
Black Hawk, HC-130, and Coast Guard Cutter. Like the P3 Orion, the Black Hawk is a versatile craft with many functions. Some require extravagant electronic sophistication. The Black Hawk is the support vehicle for the Army's major electronic warfare plane, the Common Sensor (whose own functions and equipment are not in the public record). It is also called upon for projects shared by the three branches of the military. The Joint Command Information Terminal, with twenty-five separate signal links, is designed to be installed in a Black Hawk.53
On the night TWA 800 fell, a Black Hawk and an HC-130 were flying at 3,000 feet in the clear sky, practicing refueling and preparing to drop flares in a rescue exercise.54 This particular Black Hawk was itself a rescue helicopter. Rescue helicopters often practice their actions in the absence of any other craft likely to need their help; but it is also the case that they are on hand when difficult missions are underway, missions that could imperil their participants, such as the launch of the space shuttle. If, in other words, a rescue helicopter and a Coast Guard cutter are present, it by no means indicates that a dangerous mission is underway; on the other hand, if a dangerous mission is underway, it is likely that a rescue helicopter and a cutter will be present. We do not know which of these two descriptions applies to the evening of July 17.
The Pave Hawk, as this class of Black Hawks is called, is loaded with even more instruments than many of the standard Black Hawks. Often called a rescue helicopter in military literature, the HH-60 is just as often designated a Special Operations Forces helicopter or a Missile Support helicopter.55
Its companion plane also has great versatility. The fact ,that the HC-130 is a cargo or transport plane -- it can even airlift a Black Hawk -- does not exclude the plane from the electronic fast lane. As of 1995, the Air Force began to install an "electronic suite" onto at least twenty-eight of the planes to improve their jamming, decoy-dispensing, direction-finding, and radar warning systems.56 Some of the technology planned for the millennial Orion 2000 is already on board the C-130. It should also be mentioned that the Air Force's major electronic warfare plane, Compass Call, is a modified C-130. Compass Call's exact power level, like its specific functions, is not public information but the plane is designed, says Zachary A. Lum (an electronic warfare expert), "to deliver a jamming payload in the 'bizillions' of watts and get away with it."57 The fact that Compass Call is a C-130 does not mean that the C-130 near TWA 800 was Compass Call (just as the fact that the Electric P3 Orion disguises itself as a straightforward P3 does not mean that the P3 flying above TWA 800 with its transponder off was an EP3).
What it means is this: the fact that a plane is usually identified as a submarine hunter (P3) or a neutral transport craft (C-130) should not stop us from being alert to its full range of activities. Even the standard forms of these craft carry powerful sensing, signaling, and signal-jamming equipment and take part in technologically extraordinary missions. It is in part because in their ordinary form they make such sophisticated use of radio and counter-radio equipment that they can eventually be transformed into electronic warfare versions of themselves. Information that is released to the public about one prosaic activity -- such as the P3's dropping some sonobuoys into the ocean on the night of July 17 or the Black Hawk's preparing to drop some flares into the ocean -- should not abbreviate the inquiry into the many other pieces of equipment that may have, on the same night, been in use and may have, inadvertently, contributed not to the dropping of sonobuoys and flares but the fall of a plane into the ocean.
In any inquiry into whether the C-130 and Black Hawk carry equipment that could inadvertently imperil another plane, account should also be taken of the possibility that the C-130 and Black Hawks may themselves sometimes be imperiled by electromagnetic interference. (The observation that "military airmen are better shielded than civilians" is not incompatible with the observation that "airmen sometimes appear to be themselves inadequately shielded.") In November 1996, an HC-130 traveling from Portland to a naval station near San Francisco for a training mission fell from the sky when the fuel flow to the engines inexplicably cut off.58 (Sudden fuel cutoff is listed by Colonel Quisenberry in his 1989 summary of the Air Force research on electromagnetic interference.) Ten Air Force reservists died. Because the cause of the fuel cutoff was never determined, the NTSB seven months later, at the prompting of Oregon Senator Ron Wyden, agreed to review the crash.59 By late December 1997, the NTSB had announced that it would withdraw from the case because the Air Force was unwilling to release any of its own investigation to either the public or the NTSB, thereby making any finding impossible.60 On January 15, 1998, the Air Force acknowledged that it had inadequately handled its investigation and agreed to reopen it, retrieving the plane from the ocean, and placing it against the background of seventy-two incidents over a ten-year period in which a C-130 had inexplicably lost power to all engines. In all seventy-two, the cause has been listed either as"unknown"or as "electrical."61
[Image omitted]
A C-130 cargo plane (arriving in Sarajevo, December 24, 1995)
The crash record of the otherwise virtuoso Black Hawk62 also continues to puzzle observers, even ten years after Colonel Quisenberry's Air Force study. Despite the additional shielding added to their control computers in 1989, they have continued periodically to fall from the sky, the cause of the fall either unknown or not revealed to the public. Unexplained clear-weather crashes have occurred at Fort Chaffee in 1990;63 in South Korea in 1994;64 and in a Radiant Hail exercise in 1994.65 This past July, a Black Hawk flying over the southwest portion of Fort Bragg taking photographs of the North Carolina terrain for an upcoming exercise suddenly fell through clear weather, killing eight. Among the men and women killed were a twenty-two-year-old electronic warfare equipment operator, a thirty-year-old electronic warfare and signal intelligence radar interceptor, a twenty-year-old electronic warfare and signal intelligence radar interceptor, and a twenty-six-year-old countersignals intelligence specialist.66
Like the unexplained deaths of civilians, the unexplained deaths of airmen and women should be a matter of pressing public concern. As the case of the fallen C-130 illustrates, mysterious accidents are more likely to be thoroughly researched and solved when the public (or its representatives in government) takes time to be worried about them. It is also true that dangers to aircraft (particularly dangers introduced by new forms of powerful electromagnetic equipment) can only be accurately assessed if unexplained accidents to both soldiers and civilians are made a matter of shared concern. Finally, just as it is important to learn what equipment was in use on the P3, the Black Hawk, and the C-130 on the evening of July 17, 1996, it is important to learn about the equipment in use on the Coast Guard cutter Adak.67 In addition to rescue missions, cutters are often called upon to participate in missions involving drug interdiction, illegal immigration, and the provision of assistance to other branches of the military. They therefore sometimes carry elaborate equipment. Until roughly ten years ago, a high-powered jammer (called the SLO-32) was used only on Aegis-equipped ships such as the USS Normandy; it has a total radiated power of one million watts and can jam seventy-five targets simultaneously. But as a result of the 1987 event in which the frigate USS Stark was hit by an Exocet missile, versions of the same jammer started being installed on both Navy frigates and Coast Guard cutters.68 It is more likely to be found on a class of cutter called Bear or Hamilton than the class called Island, the class to which the Adak belongs. But sometimes high-powered equipment from an Aegis or other large ship is temporarily placed on a satellite ship; and since the Aegis was in the Sandy Hook area -- the home port of the cutter on the morning of July 17 where it was, according to Admiral Kristensen, visiting Weapons Station Earl69 -- this would be among the scores of questions appropriate for inquiry. (Sandy Hook, New Jersey, is a projection of land twenty miles south of Staten Island.) The Navy and Coast Guard, needless to say, often work closely together, sharing information, equipment, and even personnel: the captain of the Adak for example, before taking command of the cutter in 1995, had himself participated in an exchange program with the Navy, serving as weapons officer on board the USS Stark.70
Aegis Cruiser. By the evening of the 17th, the USS Normandy was no longer in the Sandy Hook region. It had sailed south during the day; by the time it stopped, it was separated from the site of the TWA 800 accident by the Adak, the USS Trepang, the USS Wyoming, the USS Albuquerque, and 185 miles of ocean. Should it be included in an inquiry into a HIRF accident? There are four reasons why it should. First, we at present lack the background picture which enables us to know the largest distance at which a transmission may inadvertently harm another craft.71 Until that picture is complete, we should err on the side of inclusion, rather than premature exclusion.
Second, we lack concrete information about the ranges of electromagnetic transmissions on board the Normandy. Statements made about the range of the ship's protective umbrella -- "An Aegis cruiser near Rome can protect almost all of Europe from missiles ascending from a point in North Africa" -- usually refer to its anti-missile missiles rather than its radars; but its elaborate sensing system is there to work with its missiles and we do not know how closely the ranges of that system correspond to those of the missiles. The billion-dollar73 ship has, as impressed observers often note, antennas the size of three billboards rising above deck, and antennas trailing along behind, sonar mounted on its bow, and a sonar towed behind.74 Described by Caspar Weinberger as "the eyes and ears of an entire carrier battle group,"75 and by the press as "breathtaking," "an engineering marvel," "a miracle,"76 the Aegis can, while engaging planes or missiles, be accurately detecting and tracking "new targets from wavetop to the stratosphere," and do this while in "as much as a 30-degree roll and a 10-degree pitch."77 It is equipped with four radars (SPY-I phased-array radar, an air search radar, a surface search radar, and the twelve-foot ring of its electronically scanned interrogation antenna), various sonars, an electronic helicopter, vertical launchers, target illuminators, and a countermeasures system with a high-powered microwave beam-forming lens.78 The Aegis Guided Missile Cruiser is a gigantic exhibition hall of electromagnetic equipment.
The third reason why the Aegis should be included is that its sensing equipment is not confined to its own deck; a given transmission may therefore originate from a location far removed from the perimeter of that deck. Just as Aegis equipment can be transferred to a satellite ship, a version of its electric countermeasures equipment is designed to be carried on its Lamps helicopter. If a ship's deck were 185 miles from an accident and a ship's helicopter were 18 miles from an accident, would the location of the ship be given by the first figure or the second? (One week after the accident, Defense Department spokesperson Kenneth Bacon said there were two helicopters in the vicinity of TWA 800; the two-helicopter figure remained an enduring part of the story for six months; then, without explanation, the figure suddenly contracted down to one.79)
Tiny airborne sensing or jamming units also illustrate the problem of measuring distances by starting with the perimeter of a craft. The Navy has a 1 x 5 inch expendable jammer called POET that, when dropped from a plane, disrupts the signaling system of the plane into whose airspace it has entered (since 1986 the Navy has made 300,000 POETS, or seventy each day for twelve years)80; a similar device called FLYRT, or Flying Radar Transmitter, is designed to be launched from a ship. If devices such as these were in use (and the possibility is cited here as an example of the kind of question that needs to be asked), then the distance separating the military craft from TWA 800 would be much smaller than has been specified throughout this article.81
Finally, the Aegis should be included in the inquiry because multiple craft, according to military literature, aspire to act as a single unified weapon" or single unified sensing system. If any one of the participants is excised from the picture, no part of the picture will be accurate. The presence of the Normandy near the Maryland coastline reflects the fact that our fleet of Aegises have their home ports along the eastern seacoast." But it also coincides with the conception the Navy has of itself as it prepares and practices for war. Describing the Navy on the floor of Congress, a spokesman explained that "the blue-water Navy that once prepared to fight the Soviets on the high seas now sends its carriers along coastlines and into confined spaces such as the Persian Gulf and Adriatic Sea."" The term "blue water" is now everywhere displaced or supplemented by the word "littoral." We have a littoral Navy preparing for littoral warfare with littoral exercises."
Various kinds of Aegis instruments and practices were in an experimental state in the summer of 1996": an over-the-horizon exercise.called Mountain Top was scheduled which would require a P3 Orion to decide which of two Aegises was better positioned to attack a cruise missile (a form of attack to which the coastline Navy has to be constantly on guard), and to provide the Aegis with pictures so that it could act even if its own radar were jammed." The Aegis's ability to protect the Upper Tier-the high region of sky through which an intercontinental ballistic missile travels -- and hence ensure the defense of the homeland was also being pushed to a new stage involving the addition of experimental equipment.88
Whether the Normandy was involved in these or any other coastline experiments is among the many questions that need to be asked. We know that the Aegis's electricity was low at the moment TWA 800 fell (a piece of information Admiral Kristensen gave when he explained why the Aegis's supersensory radars contained no record of the plane's fall89). The intentional placement of a ship in the condition of low electricity is called a BECKY exercise, the acronym standing for Basic Engineering Casualty and Control. When a BECKY exercise is carried out in conjunction with a high-level military exercise, its purpose is to test whether the ship can survive even if its own radars are jammed or if it has suddenly lost electrical power. Its ability to get critical information from other craft, and to carry out self-protective actions on the basis of that information, is often what is being tested.
Would electromagnetically powerful instruments ever be turned on near the coast of New York? That might be a question to ask if we were inquiring whether any military craft had come near the airport corridors that night. But we know that ten craft were there; the craft are loaded with equipment; even their most minimal state of attention is likely to entail complicated active and passive sensing equipment. We have some idea what the lower boundary of electromagnetic complexity might be and that it is not very low. But what about the upper boundary? Would any piece of new instrumentation -- whether on aircraft or seacraft -- ever be tested off the coast of New York? The densely populated coast of Southern California (through which two planes flew terrain-masked) we know was a test site in the Radiant Oak exercise in August of 1993. We know the band of airspace outside Washington, D.C. -- from Wallops Island, Virginia, to the Patuxent River in Maryland -- is a zone for electronic warfare testing. But New York? A busy commercial airport perhaps provides a ready-made rehearsal backdrop for the kind of "shoreline clutter" the Navy anticipates in littoral combat. (As early as 1975, commercial planes entering and exiting Washington, D.C., airspace were used as a backdrop in a jamming exercise testing the country's AWACS, our Airborne Warning and Command planes.90) The fact that the Navy now aspires to protect the homeland may increase its belief that it is appropriate to bring its own maneuvers into closer relation to population centers. One can imagine a House subcommittee asking the Army, Air Force, and Navy whether there is any piece of US geography other than White Sands, New Mexico, that they are certain they know how to defend.
Would it pass through the minds of the legislators asking such questions
or the military answering the questions that this is the kind of subject
about which the population needs to be consulted? Would it occur to them
to ask whether the billions of dollars spent protecting the military equipment
against its own electromagnetism had been matched by similar expenditures
for civilian aircraft? Would they ask how one can protect the other when
the military is zooming around inside its own private, insulated envelope?
THE FALL OF TWA 800
We know the following things. When TWA 800 fell, it was flying through an
area in which ten military planes and ships were active. Because of that
activity, the environment may have been electromagnetically severe. Severe
electromagnetic environments (as the Air Force study, the NASA study, and
a statement by Raytheon's president all indicate) can cause crashes. We can
say with certainty that a High Intensity Radiation Field event -- like a
mechanical mishap -- is a possible cause of such an air crash; and we can
say with certainty that mysterious accidents are most often solved when all
their possible causes are investigated. We certainly do not know how probable
a HIRF event is. Presumably the probability level need be only very low in
order for it to be included in the investigation. Presumably the other spheres
of inquiry-mechanical trouble, bomb, missile, or cosmic debris -- have been
scrutinized whether the investigators initially assigned a 4 percent or 40
percent probability to them. TWA 800 began to suffer its catastrophe at 13,700
feet. It exploded into a giant fireball 40 or 42 seconds later, an event
recorded by a satellite." Because the black box stopped functioning at the
start of the fall, the remedial actions taken by the pilot are unknown. Only
slightly less certain than the final explosion of the plane but regarded
as highly probable is the occurrence of an earlier explosion of the central
fuel tank. Whether this happened at second 0 or second 4 or second 7 (or
some other second) is unknown. Most descriptions now assume that it happened
at second 0 because an explanation is needed for what made the plane suddenly
lose all control. But we have no clear-cut temporal record of the first explosion
(such as a visual sighting or a satellite record like that which exists for
the final fireball). Electromagnetic interference appears to be compatible
with a central fuel tank explosion having occurred at any point from second
0 to second 20. There follow below three illustrations of how a High Intensity
Radiated Field event may have affected TWA 800. In two of the three, the
central fuel tank explodes at second 0; a third one pictures how a HIRF event
could have acted if it is eventually discovered that the central fuel tank
explosion began some seconds later. They are just three of many possibilities.
A frame from the NTSB's filmic reconstruction of the paths of TWA
800, traveling east
and north, a Navy P3 traveling southwest, and a boat traveling southwest
at 30 knots per hour
("target" means radar target). The frame shows their positions 15 seconds
before TWA 800's
transponder, voice recorder, and black box stopped. The typefaces have been
altered for clarity.
Scenario 1: By July of 1997 (one year after the crash) the major
focus of the TWA 800 investigation had become the search for stray electricity
that acted as an ignition source on the central fuel tank. Under scrutiny
were locations inside the plane such as static electricity, the wiring in
a missing fuel pump, and the fuel gauges inside the central fuel tank which,
according to Boeing, have only as much electricity as "a penny dropped from
the height of two inches." By September of 1997 static electricity and the
missing fuel pump were no longer prominent in the picture, and emphasis was
placed on the possibility that electricity from high-voltage lines had suddenly
jumped to the low-voltage lines leading to the fuel gauges in the central
fuel tank, a jump occurring at one of the places where the two lines are
bundled together. By December 1997 at the week-long public meeting of the
National Transportation Safety Board, the entry of electricity into the central
fuel tank gauges from some point originating outside the fuel tank but
inside the plane was still the major concern. Boeing had earlier observed
that this would have required "an unprecedented series of accidents."
But the sudden spiking in the lines, and the jump from high-voltage to low-voltage wires, may have been prompted by a pulse of energy from outside the plane. The 1997 FAA Flight Standard Information Bulletin states that "Lightning and H[igh] I[ntensity] R[adio] F[requency] can interfere with the operation of the aircraft electrical and electronic systems by coupling electromagnetic energy to the system wiring and components."93" It further states that "a fast changing R[adio] F[requency] environment can couple voltage and current transients into the electrical/electronic equipment or components." In this way, a sudden pulse or a high-intensity field could have acted as the source of the central fuel tank ignition.
Scenario 2: (This second scenario involves higher power levels than scenarios 1 and 3, and therefore may be the least likely to have occurred. When readers of this article specializing in physics, electrical engineering, avionics, or the military have expressed a choice among the three scenarios, they have invariably chosen either the first or the third; or they have contemplated a variant on the second.94)
High-intensity radio waves could have acted as an ignition source by coming into contact with vapor coming out of a vent outlet from the central fuel tank. The FAA 1985 Advisory Circular on "Protection of Airplane Fuel Systems Against Fuel Vapor Ignition Due to Lightning" outlines the many ways that lightning can ignite a central fuel tank either by a direct strike coming into contact with the vapor from the vent or by a lower voltage corona, the "luminous discharge that occurs as a result of an electrical potential difference between the airplane and the surrounding atmosphere." The high-intensity and rapidly changing pulse from a radar, jammer, or microwave transmission would be less powerful than lightning, but the FAA document explicitly notes that the spark that can ignite a tank need only be a small fraction of the lightning's power. Though the subject of this 1985 document is lightning alone, the 1997 document on "Lightning and High Intensity Radio Frequency" directs the reader to the earlier lightning document for an understanding of both lightning and radio wave environments.95
At its public meeting in Baltimore, the National Transportation Safety Board
reported that it had included in the many subjects it researched an inquiry
into the possibility of lightning: it discovered that no lightning strikes
had occurred anywhere within a 300-mile radius of TWA 800. Whatever evidence
in the plane made lightning a possible candidate should make High Intensity
Radiated Fields a candidate as well. A year after the crash, the FAA considered
a fuel vent fire. originating somewhere inside the plane, the leading candidate
as an ignition source. Their concern about the possibility of a "flame front"
rushing down the fuel vent should (like the NTSB interest in lightning) be
looked at in relation to external radiated fields.
[Image omitted]
USS Normandy
Scenario 3: A sudden pulse of energy from a military jammer
or countermeasures system could have acted to knock the plane out of control.
Once a plane begins to fall, tearing metal anywhere on the body of the plane
can generate sparks, and those sparks might have ignited an explosion in
the central fuel tank at 4 or 16 or 20 seconds. This third path involves
the"uncommanded dive or turn" that Colonel Quisenberry describes in summarizing
the 1988 Air Force study. It is often said that this type of catastrophic
loss of power is more likely to occur in one of the new-generation, fly-by-wire
airplanes that replaces an analog system (in which mechanical links connect
the pilot's controls to the plane's control surfaces such as wing flaps and
rudder) with a digital system (in which the pilot's commands, rather than
traveling across a series of levers, are mediated by computerized electrical
signals which issue instructions to wing flaps and rudder). But TWA 800 may
have suffered this outcome, despite its age. Many planes in the 747-100 fleet
have been upgraded and retrofitted with digital equipment in the cockpit,"
a fact that the manufacturers celebrated when the plane reached its twenty-fifth
birthday. Moreover, while some people, even within the FAA, speak as though
only fully digitalized planes are susceptible to this third pathway of
electromagnetic insult,97 in fact the NASA study
takes a much more moderate position, stating only that fly-by-wire "may be
more sensitive" to the problem than older analog planes.
In 1990, reports Martin Shooman, a blimp flying over a Voice of America radio transmitter lost both engines and its ignition system, but managed to execute a successful emergency landing. In 1983 a military fighter in Germany crashed 1.8 miles from a Voice of America transmitter. (The electric field strength of the transmitter that caused the crash, 70 volts per meter at the transmission site, is less than a Navy jammer that can simultaneously affect seventy-five different threats and has a "total radiated power of 1 million watts."98) In a 1991 incident, a commercial plane flying from Taipei to Los Angeles felt into a "vertical roll," dropping from 41,000 feet to 11,000 feet in two minutes before the pilot "regained control."99 If it were to turn out that the blimp had an analog or a fiber optic system, would it be wise simply to ignore the possibility of an HIRF event, even with a powerful transmitter sitting under the airship? Is it prudent to ignore this third pathway with regard to TWA 800 even when we know there were powerful transmitters nearby such as those that can be carried on a P3 and at least some of the other nine craft in the area?
The cockpit voice recording on flight 800 contains, as has been widely observed, no obvious record of the disaster awaiting the plane's passengers and crew. But if electromagnetic interference one day comes to be held responsible, we may listen again to that voice recording and hear in the pilots' words the first tremors of the event. Registered there may be the two problems Colonel Quisenberry identified as the classic signature of electromagnetic interference: sudden interruption in fuel flow and false instruction to the control surfaces on the wing flaps or rudder. One minute and fifty seconds before all electricity ceases on TWA 800, the Captain comments on the fuel flow: "Look at that crazy fuel flow indicator there on number four."100 Five seconds later he continues to look at the indicator, directing the First Officer's attention to it: "See that." Ten seconds later he expresses the sense that the wing flaps are not in the right position,101 and he now works to adjust them, an action called trimming: "Somewhere in here I better trim this thing (in/up)." His copilot doesn't understand or hear ("Huh?") and the pilot repeats: "Some place in here I better find out where this thing's trimmed." Trimming is a routine process but his words -- "Somewhere in here. . . . Some place in here," "I better trim this thing. . . . I better find out where this thing's trimmed" -- suggest that the plane does not handle with the split-second responsiveness the pilot is seeking. The time interval in each of these interactions is small, only seconds. But just as one would be alarmed if in turning the steering wheel of the car there were a three-second pause before the car began to turn, so the pilot's sentences suggest the expectation of greater agility than the plane now gives.
The same is true of the final conversation which begins thirty seconds later, less than one minute before the cessation of all cockpit, transponder, and black box recordings. Boston Control Center instructs the pilots to climb from 13,000 to 15,000 feet: "TWA eight hundred climb and maintain one five thousand." The Captain issues an instruction to the Second Officer to adjust the plane's power level, "Climb thrust," and the First Officer recites back to Boston the words they have received, "TWA's eight hundred heavy climb and maintain one five thousand leaving one three thousand."
Now the Captain addresses his Second Officer as though the Second Officer has not yet carried out the instruction (that is, the plane feels to the Captain like a plane that has not yet received an increase in power): "Ollie . . . Climb thrust." And three seconds later "Climb to one five thousand." The Second Officer assures him the command has already been carried out: "Power's set." Here the voices cease. Any words spoken before a catastrophe may later come to sound prescient: the First Officer's steady name for the flight ("TWA 800 heavy") or the Captain's description of the plane's moaning ("Seems like a homesick angel") may come to bear the weight of a sorrow the words never had at the moment they were spoken. At the same time, because of their acuity of observation, the pilots are indeed likely to be prescient of events that are about to, or have already begun to, happen. It is because pilots have a supersensory intimacy with the plane they are flying that their power to diagnose the plane is relied upon and their cockpits are equipped with voice recorders.
Each of these three pathways described above would involve an electromagnetic event at second 0, an event powerful enough to knock out the plane's transponder, cockpit communication system, and black box simultaneously. Each would involve an electromagnetic event that could have had, as one feature, visible light of the sort described by men and women on the ground below. Perhaps electromagnetic waves are responsible, but the pathway is different from any of these three. Perhaps further investigation will show that electromagnetic events had nothing to do with the disaster. Until the relevant information about the electronic equipment used on the night of July 17, 1996, and the relevant Air Force and Pentagon studies, are made public, we simply won't know.
"The investigation will be incomplete if it fails to evaluate the radio frequency interference issue," says Rear Admiral (retired) Eugene J. Carroll, Jr., Deputy Director of the Center for Defense Information. As commander of an aircraft carrier defense task force, he witnessed problems with electromagnetic interference on a carrier first hand. He is also knowledgeable about problems elsewhere, such as on the ten-story missile warning radar in Georgia that can see a small object 1,500 miles away but, in the late Eighties, placed nearby military pilots in danger of being automatically ejected from their seats. "The military has known about these problems for a long time. It's time for the civilian population to know about them as well."
Rear Admiral Carroll's double focus on opening up the TWA 800 inquiry and on educating the civilian population is shared by other experts. The physicist and electronic engineer D. V. Giri is a former research associate on electromagnetic pulse at Phillips Laboratory, Kirtland Air Force Base, New Mexico, and has designed both antennas and filters for microwave systems. Giri, who does not see electromagnetic interference as a likely cause of the crash, nevertheless, a comment for The New York Review on a draft of this article, gave the following five reasons why the possibility should be the subject of an inquiry:
First, "completeness: it is simply unacceptable to close out the case as an unsolved mystery."Second, "to respond to the civilian society's . . . justifiable need for information and reassurance."
Third, "as a moral issue, if it can be proved that military activities caused the accident, there needs to be acknowledgment of responsibility, sooner than later."
Fourth, "the technology of high-power transient sources and radiators has significantly matured in the last decade."
Fifth, "increased sophistication of on-board electronics generally lowers the vulnerability thresholds."
Martin Shooman, the author of the NASA study on the occurrence rates of HIRFs -- as well as other studies of occurrence rates in aircraft and satellite electronics -- agrees that electromagnetic interference should become part of the inquiry. He specializes in applying scientific measures of probability to issues of safety and risk. "The exclusion of this subject from the TWA 800 inquiry would be understandable if some other cause had quickly come forward as an explanation. But that didn't happen. The possibility of a High Intensity Radiation Field event must be given very careful consideration. After doing so, it may be possible to eliminate it as a cause. But not before."
One prominent physicist, asked if he could come up with a reason why HIRFs should be disregarded as a possible cause of the TWA 800 crash, said he could not. After several weeks of thinking about the subject he reported that he still could not: "Nor can any of my graduate students," he added. "Nor can any of the colleagues to whom I have posed the question." David Wunsch, an electrical engineering professor at the University of Massachusetts, Lowell, who has dedicated any years to the study of antennas, adios, and the reception of signals, concludes, "In the long run, we may come to see this issue of aviation and military electronics as another 'silent spring.' " His words refer to a moment hat marked the overnight transition from ignorance about an environmental problem to abiding concern. "One day no one knows about the problem, the next day everyone does."
[Image omitted]
Wiring and other wreckage recovered from TWA 800, August 8, 1996
THE DISTRIBUTION OF
KNOWLEDGE
Three practical recommendations follow from the considerations presented here.
-
First, the subject of electromagnetic interference should be made part of
the TWA 800 inquiry (as well as of the inquiry surrounding any plane whose
crash has no sufficient mechanical or weather explanation).
-
Second, to assess the possibility of electromagnetic interference, the men
and women in nearby military planes and ships should describe the instruments
in use that night.
- Third, the seven-month Air Force study and the three-year-long Pentagon study that chronicle the ways electromagnetic interference has affected military planes and ships should be opened either to the citizenry or to the inquiry panels of TWA 800 and other unexplained commercial downings.
I have suggested that concrete descriptions of the evening of July 17, 1996, be given by the men and women who occupied, and therefore have intimate knowledge about, the particular military craft (rather than abstract summaries by, for example, the Commander of the Second Fleet or one of the Chiefs of Staff). I have suggested this because of my general belief that the servicemen and women are -- even more than the radar, sonar, and optical-electrical equipment -- the eyes and ears of the country's defense. If the radar is on, but men and women are prohibited from speaking the country has lost not only its most acute sensory apparatus but its only apparatus that is ethically grounded.
Sometimes "national security" is invoked to restrict communication between military and civilians. But the explanations sometimes given for "national security" during peacetime do not apply to the case at hand, in which relevant military information could, at least, be made available to the official inquiry of the NTSB, and to the congressional committees concerned with public safety. Moreover, even if highly unusual equipment was in use or a top-secret demonstration was underway (such as Radiant Clear, designed to test the interaction of multiple sensors over coastal waters), most new instruments and practices are shared with other countries soon after they are first used here. By 1995, our Radiant Hail technology had already been shared with Bosnia and with South Korea.102 The Aegis technology is shared with Japan and Spain, and scaled-down versions of SPY-I radar have been offered to South Korea, Turkey, and Australia103; P3 Orions are owned by over fourteen countries104; Black Hawks have been purchased by twenty-three (the worst peacetime military accident in Australia's history involved two Black Hawks105). As, finally, electromagnetic equipment is internationally shared, so too is information about electromagnetic interference.106
Sometimes it seems that US civilians are the only people who do not yet have the information whose protection has prompted and excused the high-security fence. At present, the civilian and the military have become two separate worlds. All we share is the "Don't ask, Don't tell" rule: civilians will agree not to ask if the military agrees not to tell. But a democracy requires that the military be held within a civil frame, that the military be accountable to civilians, and ideally, that responsibilities for military acts be distributed widely across the whole population. The result of ignoring these requirements is the intellectual disenfranchisement that has come to be routine in recent decades.
What Is Known, Half Known, and Unknown
In an airplane, such a signal may begin to throw off the compass or misinform the pilot about the plane's direction or distance from a certain location. Such misinformation is unwelcome at any altitude; but at critical moments -- takeoff, landing, moving through dense air traffic -- it is potentially fatal. The unwanted signal, if sufficiently intense, can also bring about dire effects more directly. It can -- as both the Air Force study and the NASA study cited in this article suggest -- suddenly enter into the computer the pilot uses to give commands or it can enter into the wiring of the plane itself. By either route, it can issue a "false" instruction, suddenly causing the flaps on the plane's wings to raise, for example, or the fuel system to turn off. If the interfering signal is stronger than the signal the antenna is trying to receive, the chance of interference increases. In absolute terms, the level of power required to create false information or even a false command is relatively low. But if the radiated power is high enough, it can go on to produce another form of damage: it can directly burn out one or more electrical circuits. If the radiated power is still higher, it can even cause an electrical spark. (Sparks can happen at much lower power levels if assisted by appropriate arrangements of metallic conductors inside the plane; but at a high enough power level, sparking can even take place without such assistance.) The power levels required to produce each of the three outcomes differ greatly: one physicist estimates that microwatts are needed to introduce an unplanned signal into a system, hundreds of watts to burn out an electric circuit, and tens of kilowatts to introduce an unassisted spark. Sparking is not unusual at the site of transmission (one sometimes sees it when flipping a light switch), but it is very unusual at the site of reception since the radiated power, upon arrival, is much weaker than at its transmission site. The three forms of interference that can be introduced by humanly produced electromagnetic transmissions can also be introduced by a naturally occurring source, the staggeringly powerful electromagnetic signal called lightning. Lightning contains power levels far beyond what is carried in most humanly produced radio waves, but lightning also contains power levels far beyond what is needed to produce unplanned signals, burnout in an electric circuit, or sparking. "Pulsing," "spiking," or a rapidly changing radio environment is often involved in electromagnetic interference. A pulse is an event in which the signal intensity increases for a brief moment, then subsides; because the time interval is so short, a power level can be achieved that is much higher than when the signal is steadily transmitted. Megawatts of power can be reached for a microsecond and this peak power can have strong effects on a system, despite the brevity of the event. Pulsing can work at any of the three power levels described above, though it always refers to the moments of highest signal intensity relative to the average level being transmitted. The distinction that has so far been made here between those radio signals that are "wanted" and those that are "unwanted" refers to the site of reception: it is the pilot or the plane's antenna that "wants" or "does not want" the signal. But what about the site of transmission? Here discriminations must be made among four situations. The first is an inadvertent transmitter causing inadvertent interference: a laptop computer is not supposed to transmit signals but if its interior shielding is inadequate, it may leak accidental emissions. The second situation entails an intentional transmitter causing inadvertent interference: a cell phone purposely transmits but has no intention of transmitting to the plane's instruments. Because it is an intentional transmitter, the likelihood that it will interfere is higher than the computer's and therefore its use on a plane is prohibited not just during takeoff and landing but at any altitude. A huge radio transmitter on the ground, such as the ones used by Voice of America, also belongs to this category. (It is much farther away from the cockpit than the passenger-carried cell phone but also has vastly higher power levels.) It has every intention of transmitting, but has no intention of transmitting to a plane's instruments. Because it is nevertheless likely to do so, its location is marked on aviation maps and pilots avoid it. The third situation entails intentional transmitters causing intentional interference. A military jammer purposely transmits the very signal frequency its target receiver is looking for: it does this in order to disrupt, or overwhelm, that target receiver. Because it intends harm, it is likely to use high power levels; it may also change power intensity and frequency abruptly, thereby using pulsing to bring about disturbance. It may have effects of longer duration and more gravity than intended if, seeking to block signals for only a few minutes, it instead accidentally burns out a circuit. This would carry us to the fourth situation: an intentional transmitter designed to bring about intentional interference instead brings about unwanted interference, either by causing more enduring consequences than intended or, alternatively, by somehow straying to the wrong target. If, for example, a P3 Orion were trying to jam a C-141 Starlifter (in order, say, to test the resistance to jamming in the Starlifter's new electric wing flaps) and if the signal accidentally strayed to a commercial 747, that would be an instance of this fourth category. Again, if the P3 Orion sent out a disposable jammer that dropped too close to the Starlifter, burning out its circuits, that would be an example of the fourth category. A jammer, unlike microwave and pulse weapons, is not designed to burn out electrical wires. (If a microwave beam burned out an electric circuit, that would carry us back to the third category of intentional transmission causing intentional interference, unless the beam strayed to an unintended target, which would again be the fourth category.)
A large body of concrete information about radio wave interference from military
planes has been collected by the military itself. These studies examine the
inadvertent effects of military planes on other military planes rather than
on commercial planes. There are differences between the two: commercial planes
tend to be more aerodynamically stable than military planes but also less
shielded and (because of the type of fuel they use) less protected against
fuel fires. Despite such differences, the military studies would supply civil
society with the material it needs to begin to assess the problem. -- Elaine
Scarry |
Notes
1 For a review of case studies by the Radio Technical Commission for Aeronautics, see Christina Del Valle "Could a Laptop Bring Down an Airliner?" Business Week, October 14 1996, pp. 90-92; for an analysis of the FAA regulation 91.21 by a leading electrical engineering journal, see Tekla S. Perry and Linda Geppart, "Do Portable Electronics Endanger Flight?" IEEE Spectrum, Vol. 33, No. 9 (September 5,1996), pp. 26-33.
2 Don Herskovitz, "Killing Them Softly; New Electronic Warfare Applications," Journal of Electronic Defense, Vol. 16, No. 8, p. 41ff.
3 There does not at present appear to be any automatic procedure for making available to commercial pilots (or to accident investigation panels) the exact location of military craft and the particular transmitters in use at the time an anomalous incident occurred. This statement is self-evidently true in the case of transmitters: a year and a half into the most expensive airplane accident inquiry in history, we still have no idea what military transmitters were in use.
But even the simpler fact of location can sometimes have ambiguities caused by the radar-evading design of some military planes (Stealth B-2, F-22, Navy Prowler) and radar-evading practices such as flying without a working transponder, an electronic device located on the belly of a plane that enables air controllers, using radar, to identify the plane on their radar screens without making a verbal request for identification. Because a transponder gives air controllers a clear reading of both a plane's identity and its precise altitude, tracking a plane without this information can be difficult. (Recall the spring of 1997 when the transponder on Craig Button's A-10 stopped working; the Air Force was able to reconstruct the A-10's path across Arizona and Colorado not by using radar records but by using the reports of citizens on the ground who had spontaneously taken note of the plane.)
4 "Industry Officials Still Frustrated with FAA Policy on HIRF Testing," Weekly of Business Aviation, January 14, 1991, p. 11.
5 Flight Standards Information Bulletin for Airworthiness, FSAW 97-16A, "Lightning/High Intensity Radio Frequency (HIRF) Protection Maintenance," August 4, 1997.
6 Martin L. Shooman, "A Study of Occurrence Rates of Electromagnetic Interference (EMI) to Aircraft with a Focus on HIRF (External) High Intensity Radiated Fields," National Aeronautics and Space Administration, Langley Research Center, Hampton, Virginia, April 1994, pp. 2, 7, 20.
7 Quisenberry quoted and summarized in Mark Thompson, "Mixed Signals May Have Misguided US Weapons: Pentagon Probing Electronic Interference Also Suspected in F111 Crash During Libya Strike," The Washington Post, January 22, 1989, p. A4.
8 Quisenberry quoted in Mark Thompson, "Radio-Wave Blizzard Probed in $35 Million Pentagon Study," Orange County Register, January 20, 1989, p. A18 (a story similar but not identical to the Post story). The seven-month study was also described in John Morrocco, "Pentagon Approves Joint Testing to Identify, Correct EMI Conflicts," in Aviation Week and Space Technology, December 19, 1988.
9 Quisenberry quoted in Thompson Mixed Signals", Quisenberry's judgments about the Black Hawks are also summarized in Thompson's Orange County Register and Morrocco's Aviation Week stories.
10 "Ordinary Radio Waves Allegedly Can Knock Down Combat Copter," Los Angeles Times, November 9,1987, p. A4.
11 Thompson, "Mixed Signals," and "Radio-Wave Blizzard Probed." The problems encountered by US aircraft in Libya had earlier been reported in the press, though the phrase "electromagnetic interference" had not been used. Five Air Force F111s and two Navy A-6 attack jets had aborted their mission after suffering problems with navigation equipment and bomb-dispensing mechanisms (The New York Times, April l7, 1986, p. 22, Los Angeles Times, April 17, 1986, p. 1, and April 23, 1986, p. 12; The Washington Post, April 20, 1986, p. A1). The eight affected planes -- seven disabled and one that crashed -- represented one fourth of the attack group of thirty-two planes (Facts on File, April 18, 1986, p. 257). The F111 that crashed was seen by Navy pilots as it "exploded" in "a fireball" or "a fiery ball" that then disappeared into the ocean a few miles from shore (The Washington Post, April 16, 1986, p. A1, and April 20, 1986, p. A1; Chicago Tribune, April 16, 1986, p. C5; Time, April 29, 1986, p. 28). The fact that electromagnetic interference has now been judged a possible cause of the plane's fall means that there is nothing incompatible between interference and explosions, a fact relevant to the TWA 800 inquiry.
12 Dan Thompson and Carlos Bedoya "Optical Fiber Finally Takes Off," Photonics Spectra, Vol. 29, No. 4 (April 1995). The electric field a Navy plane can withstand is 2,000 volts per meter.
13 Thompson, "Mixed Signals."
14 Zachary A. Lum, "Pump Up the Volume," Journal of Electronic Defense (summarizing a statement made by Colonel Mel Heritage, project manager for signals warfare at Vint Hills, Virginia), Vol. 17, No. 6 (June 1994), p. 34. (See also Defense News, January 23, 1994.) Compass Call was cited by Colonel Quisenberry in 1989 as an instance of a plane that needed to be studied for the inadvertent effects it might be having on other craft (Morrocco, "Pentagon Approves Joint Testing").
15 "Increasing civilian use of the electromagnetic spectrum increases signal density and also makes it easier for a jammer to be seduced into action against a non-target signal," states Norman Friedman in his description of the Prowler in both the 1991-1992 and 1997-1998 editions of Naval Institute Guide to World Naval Weapons Systems.
16 Vice Admiral Steve Abbot, US Navy Commander Sixth Fleet, testified before the Military Readiness Subcommittee of the House National Security Committee about the series of firsts achieved by the Aegis in Bosnia: "First use of T[omahawk] L[and] A[ttack] M[issiles] in Eucom; First use of TLAM in support of NATO; First use of Block III missiles; First use of G[lobal] P[ositioning] S[ystems] only missions. " March 4, 1997.
17 Antony Preston, "Designing Surface Ships for the Next Decade," Armada International, Vol. 13, No. 6 (December 1989), p. 50.
18 International Defense Review, June 1, 1997, p. 1; Photonics Spectra, April 1995, p. 82; Electrical Engineering Times, June 24,1996, p. 37; statements about the immunity of fiber optics also occur in nondefense areas such as Library Technology Reports, July 17, 1996, p. 489; Sensor Business Digest, April 1, 1997. For a description of research challenging the immunity of fiber optics to electromagnetic interference, see Aviation Week and Space Technology, February 14, 1997, p. 52.
19 Arthur Wegner summarized, then quoted in "Raytheon to Fly by Light," Business and Commercial Aviation, Vol. 7, No. 1 (July 1995), p. 24. During the 1993-1996 period, Raytheon was testing a Beechjet with fiber optic controls which Wegner believed would become a model for future control-by-light aircraft (see, for example, Aviation Week and Space Technology, May 2, 1994, p. 51, and "Raytheon Plans Fibre-optic Controls Within Five Years," Flight International, May 24, 1995).
20 It would also help protect a craft that is subjected to electromagnetic attack from terrorists, a newly emerging concern not only in the US military but among international scientists. For the military concerns, see the recent statement made before Congress by David Schriner of the Electronic Warfare Association about "a new form of H[igh] P[owered] M[icrowave] weapon called T[ransient] E[lectromagneticl D[evices] that Schriner worries can be used against "financial institutions, aircraft . . . and other critical equipment" (Joint Economic Committee Hearing, R[adio] F[requency] Weapons and Proliferation, February 25, 1977). The concern is evident among international scientists in the July 15, 1997, meeting in Montreal of the IEEE and the International Union of Radio Scientists (URSI) that devoted a panel session to the subject of "electromagnetic terrorism." The session heard a paper on this subject by General Major V.M. Loborev of the Russian Federation Ministry of Defense.
21 Quisenberry quoted by Thompson in "Radio-Wave Blizzard Probed" and "Mixed Signals."
22 An example of a craft that first suffered an incident of electromagnetic interference and then underwent a modification is the American carrier USS Forrestal. During the Vietnam War, the shipboard radar on the Forrestal, brushing across its own deck, hit an insufficiently shielded wire, activating a 5-inch Zuni rocket (Don Herskovitz, Journal of Electronic Defense, Vol. 26, No. 8 [August 1993], p. 41ff). As of the early 1990s, the Forrestal's electronic countermeasures system was scheduled to receive a fiber optics modification that was designed (among other benefits) to reduce the carrier's vulnerability to electromagnetic interference (Friedman, World Naval Weapons Systems 1991-1992, p. 530). Although the Forrestal itself has been decommissioned, the fiber optics revision has been incorporated into other carriers such as USS Kitty Hawk. On the incorporation of fiber optics into helicopters perceived to be vulnerable to interference, see "Air Force Pursues Photonics Research," Aviation Week and Space Technology, January 30, 1989, p. 60.
23 As the title "Occurrence Rates" suggests, the NASA study cited earlier (see footnote 6) explicitly seeks to determine how often High Intensity Radiated Field events take place. HIRF events (including those ranging in seriousness from the most minor fluctuation in, an instrument reading to the most critical upset of causing a crash) have a frequency which falls, according to Martin Shooman, in a range between one in ten thousand flight,hours and one in one hundred thousand flight hours (p. 28 and table 7.3 on p. 54). In order to place these numbers in a context where they can be assessed, Shooman then compares them to other events whose frequency is extremely low but which are nonetheless held to be important to the public (such as deaths from disease and deaths from rail, bus, automobile, and plane accidents). HIRFs of all levels of seriousness occur "about 100 times as frequently as transportation fatalities" (p. 28). The NASA study calls attention to the need for future studies; and describes the difficulty of determining occurrence rates for an event that is both uncommon and also "sometimes shrouded in secrecy." Such studies, the NASA report concludes, require "confidential, nonpunitive incident reporting schemes" (p. 8). The study also describes an anticipated increase in HIRF events caused by new electronic systems and increased use of composite materials in airplane bodies (p. 3).
24 Although the Electromagnetic Compatibility Analysis Center rarely shows up in the public record, it appeared in the press announcements of the 1988 Air Force study of radio waves interference. It was also mentioned in news articles in 1980 when it contemplated moving to Minnesota (the home state of the country's vice-president): its proximity to the Pentagon was given as the reason it remained in Annapolis ("Defense Renovating Facility That May Move to Minnesota," The Washington Post, February 15, 1980). The center has a publicly listed phone number, but is not -- in the author's experience -- reachable by a public phone. [See also the U.S. Department of Defense Joint Spectrum Center: http://www.jsc.mil ]
25 Aviation Week and Space Technology, December 19, 1988, and February 3, 1992; Aerospace Daily, December 4, 1991; Thompson, "Radio-Wave Blizzard Probed."
26 The two crashes have been attributed to rudder control problems; but controversy continues over the cause of the sudden rudder deflection.
27 National Transportation Safety Board, Public Hearings.
December 10, 1997, Morning Session: Chairman Jim Hall addressing George Slenski, Air Force scientist at Wright Laboratory who in 1990 completed a study of 652 electrical mishaps in military planes: "Who pays your salary, Mr. Slenski? . . . So the taxpayers pay your salary? . . . The Chairman as a taxpayer pays both for the salaries of the FAA and the United States Air Force. . . . So he's very interested if there's important information generated through his tax dollars [about] research that affects aviation safety that that information get out." Hall now addressing Chris Hartonas, FAA aerospace engineer: "Are you familiar with the work that Mr. Slenski has done?"
December 10, 1997, End of Morning Session: Jim Hall addressing Jerome Hulm, electrical systems manager for Boeing: "Do you all manufacture for the Air Force as well? . . . Do you share information?"
December 11, 1997, Mid-afternoon Session: Jim Hall discussing electrical wiring with Alex Taylor and Bob Vannoy: "Doesn't the Air Force operate Boeing military equivalents? . . . Are there any military Air Force 747s that are classics? . . . I do have a general concern about how the information is transferred [between military and civilians]. I have the opportunity to meet with Administrator Garvey next week. I'm going to ask her to look into being sure that safety information we get in the military and the commercial [realms have] bridges of transfer [between them]."
December 11, 1997, Late Afternoon Session: Jim Hall addressing George Slenski about his research for the Air, force on wiring: "You might share that information with the FAA if they don't already have it."
December 9, 1997: Noon Session: Jim Hall addressing Beatriz Rodriguez from the Air Force and Jerome Hulm from Boeing about inspections of bonds inside central fuel tanks: "You say it's already been accomplished on Air Force One. I'm sure most citizens would want it accomplished on the 747 they're on as well."
28 Robert L. Gardner, an Air Force scientist at Phillips Laboratory who has chaired Commission E on electromagnetic interference at the International Union of Radio Scientists, states that the military achieves precision not by testing the effect of waveforms on all possible aircraft and ship equipment (an impossible proposition) but by charting out all tested instances (specified waveforms at an array of intensities on as many systems as possible) from which some "predictive capability" can be derived for anticipating the effect on an untested system. The goal of bringing about "system lethality" -- defined as "preventing the target system from carrying out its mission"-- can be accomplished either by "burnout of a critical electronic circuit" or by temporary attachment of the waveform to one of the target system's functions which causes an interruption in that function. Bringing about either outcome requires choosing "a waveform that couples efficiently to something important in the system" but "something" defined with enough precision so that the waveform does not end up straying to unintended targets and disrupting many more systems than intended. ("High Power Electromagnetics," Proceedings of EMC [Electro-Magnetic Compatibility], Zurich Symposium, 1997, Supplement, p. El.)
29 Mark Thompson summarizes Pentagon officials as stating that the transmissions causing Army Black Hawk crashes were "routine radio waves from microwave towers, radio antennas and radars" in "Routine Radio Waves Blamed in High-Tech Copter Crashes," Orange County Register, November 8, 1987, p. Al. As the date indicates, this article appeared more than a year before Colonel Quisenberry's statements about the problem.
30 Taylor and Francis, 1994. Taylor and Giri state that the microwave technology available in 1994 can reliably disable unprotected electronic systems at ranges of 30 kilometers from a high-power 1-GHz source and will soon increase a hundredfold in radiated power (p. 197). Although the book focuses on defensive weapons, the authors note "the most common" application of high-power microwave systems "is high-resolution radar" (p. x; and on the connection between high-resolution radar and microwave weapons, see footnote 93 below).
31 Thompson quoting a senior Navy engineer in "Routine Radio Waves Blamed," p. Al.
32 This fact, originally provided by Boeing, was constantly repeated during the NTSB Public Hearing in Baltimore, December 8-12,1997.
33 Simon Michell, editor, Jane's Aircraft Upgrade, p. 312.
34 Baum, "From the Electromagnetic Pulse to High-Power Electromagnetics," in Proceedings of the IEEE, Vol. 80, No. 6 (June 1992), p. 802.
35 See, for example, eleven articles examining Baum's technique in Electromagnetics, Vol. 1, No. 4 (October-December 1981), "Special Issue on the Singularity Expansion Method," edited by L. Wilson Pearson and Lennart Marin. For Baum's description of the method and for a context for the problem, see L. B. Felsen, editor, Transient Electromagnetic Fields (Springer, 1976). For a recent overview, see C. Baum, "The Theory of Electromagnetic Interference Control" in Modern Radio Science, edited by J. Bach Andersen, published for the International Union of Radio Science (Oxford University Press, 1990), pp. 87-101.
36 See, for example, J. P. Parmantier, G. LaBaune, J. C. Alliot, P. DeGauque, "Couplages Electromagnetiques sur des Systemes Complexes: Approche Topologique," in La Recherche Aerospatiale, No. 5 (1990), pp. 57-70.
37 Baum, "From the Electromagnetic. Pulse to High-Power Electromagnetics," p. 810. Pilots, according to Mark Thompson, make the same observation, complaining that the Army tests their craft by a single blast of radio frequency on the ground, rather than the complex array of radio interference they actually encounter in the air ("Routine Radio Waves Blamed").
38 "Military Area Near Crash Zone Was Active when TWA 800 Exploded," Aerospace Daily, Vol. 179, No. 41 (August 28, 1996), p. 306. Riverside, California's Press-Enterprise reports that the military had placed off-limits to civilians 19,000 square miles comprised of W-105, W-106, and "a special 7,800-square-mile block of airspace straddling a major Atlantic air route about 120 miles southeast of Kennedy Airport and east of Cape May." (David E. Hendrix, "Flight Skirted Restricted Area," Press-Enterprise, March 10, 1997.) "The word "transponder" conflates "transmitter" and "responder," because when a signal is transmitted to the device, it automatically responds with a self-identifying signal. Though we have not been told why the P3 had its transponder off, it seems reasonable to assume that it did not wish to be at every moment self-announcing.
40 The information cited about these five craft has been fairly consistent across both official announcements and news reports. In cases where there is conflicting information, either the most persistent or internally consistent figure has been used here. For example, the P3 Orion has been described as 6,000 feet above TWA 800 by the National Transportation Safety Board (Public Hearing, Baltimore, December 8, 1997) and many other sources; therefore that figure is used here even though Defense Department spokesperson Kenneth Bacon, speaking at a news briefing one week after the crash, positioned the plane only 3,000 feet above TWA 800. (Because the P3's transponder was not working, there is no radar record of its altitude.) The Normandy has been consistently placed by Navy, State Department, and FBI spokespersons 180 or 185 miles southwest of the crash; the land formations named, in contrast, have sometimes been inconsistent with one another and with the stated mileage. Roughly six months after the crash, the number of helicopters contracted down from two to one: the number "one" has been used throughout this article but the contradiction is problematic enough that attention is briefly called to it later in the article. The helicopter's distance from the crash has most often been given as five miles, but has varied up to ten; the figure of five is consistent with statements made by the pilots about how quickly they arrived at the scene: for example, the pilots "said they kept their eyes on the fireball and arrived while debris and bodies were still falling from the sky" (David E. Hendrix, "CIA Analysts Say Missile Didn't Fell TWA Flight 800," Press-Enterprise, September 25, 1997).
41 Transcript, "News Conference with Federal Officials," Federal News Service, November 8, 1996.
42 James Kallstrom, Business Executive Luncheon, Kennedy International Airport, March 20, 1997. Kallstrom's revelation that the P3 was directly overhead was prompted by the need to clarify radar images that appeared to show two objects converging and that had been interpreted by Pierre Salinger to record a missile hitting the commercial liner (Chicago Tribune, March 21, 1997, p. 19). A radar map presented at the NTSB Public Hearing (December 8. 1997, Late Morning Session) showed TWA 800 as a coherent pattern of marks, abruptly stopping and dispersing at the point its path intersects with the radar tracks of the P3's path.
43 Molly Moore, "For the Navy, the Lockheed Orion Turns Out to Be Lazarus," The Washington Post, September 20, 1987, p. A17; Fred Hiatt, "Navy Buyers Seeking Bids," The Washington Post, October 23,1984, p. A3; The Washington Post, November 27, 1985.
44 Air Force Magazine, June 1996, p. 74.
45 A single-letter practice was followed in the official announcement of all military craft in the vicinity of TWA 800 made by James Kallstrom.
46 Kenneth Munson, Air Force Magazine, July 1993, p. 78.
47 Rear Admiral Kristensen, Transcript, "News Conference with Federal Officials," Federal News Service, November 8, 1996. Sonobuoys dropped onto the surface of the ocean enable a plane to determine, by echo soundings, the location of submarines and the terrain of the ocean floor.
48 International Defense Review, July 1, 1994, p. 51.
49 Journal of Electronic Defense, Vol. 19, No. 7 (July 1996), p. 26. It is as though the treasure of national resources has been relocated to the electromagnetic spectrum: Radiant Coal, Radiant Zinc, Radiant Mercury, Radiant Beryllium (newly released, these names occur on pages added after the printed index in Friedman's Naval Institute Guide to World Naval Weapons Systems 1997-1998).
50 Aerospace Daily, Vol. 169, No. 56 (March 23, 1994) p. 449. See also Journal of Electronic Defense, Vol. 17, No. 8 (August 1994). p. 33.
51 Aerospace Daily, March 23,1994, p. 449. See also Journal of Electronic Defense, August 1994, p. 33.
52 International Defense Review, July 1, 1994, p. 51.
53 International Defense Review, December 1, 1995, p. 9.
54 Aviation Week, July 22, 1996, p. 20.
55 "Air Forces of the World-USA," Flight International, July 5, 1995.
56 Aerospace Daily, Vol. 175, No. 39 (August 28,1995), p. 308. The radar of transport airplanes is sometimes listed among the airborne sources of High Intensity Radiated Fields, as is search and rescue radar (Aviation Week and Space Technology, September 2,1991).
57 Lum, "Pump Up the Volume."
58 "Fuel Flow Fault Caused 1990 HC-130 Crash," Periscope Daily Defense News Capsules, April 25, 1997.
59 Defense Daily, Vol. 195, No. 49 (June 9, 1997).
60 Phone conversation with Jeffrey Renner, legislative assistant in the office of Oregon Senator Gordon H. Smith, January 2, 1998.
61 Matthew L. Wald, "Air Force Panel Wants Search For a Downed Plane Resumed," The New York Times, January 16, 1998, p. A20.
62 The Black Hawk also had an independent engine problem that occurred 150 times before it was eventually repaired, but only in 1995 did it eventually kill someone (Defense News, June 17-23, 1996).
63 "Fort Chaffee Crash Kills Five," Arkansas Democrat-Gazette, July 29,1990.
64 "Korean Air Force Chief Killed in Helicopter Crash," Agence France-Presse, March 3, 1994.
65 International Defense Review, July 1, 1994, p. 51.
66 News and Observer (Raleigh, N.C.), July 12, 1997; July 13, 1997, p.B2.
67 The first ship on the scene of the accident, the first crew to begin lifting bodies out of the water, the Adak has been widely and justly praised for its rescue efforts.
68 Friedman, Naval Institute Guide to World Naval Weapons Systems 1997-1998, p. 552.
69 Admiral Kristensen, Transcript, "News Conference with Federal Officials."
70 James A. Broderick, "Changing Command," Asbury Park Press, June 24,1995, p.3.
71 Information about power levels and ranges is at present too fragmented to enable one to form a picture. Recently, for example, a million-watt laser illuminated (but did not damage) a satellite 300 miles away; during the same week a tiny 30-watt laser (shone through a mirror) successfully blinded a satellite also 300 miles away (Defense Week, Vol. 18, No. 48, December 8, 1998).
72 Greg Canavan, a senior scientist at Los Alamos, cited in Michael A. Dornheim, "Missile Defense Design Juggles Complex Factors," Aviation Week and Space Technology, Vol. 146, No. 8 (February 24, 1997).
73 "National Defense Authorization Act for Fiscal Year 1995 and Military Construction Authorization Act of Fiscal Year 1995 -- Conference Report," Congressional Record, Vol. 140, Senate [1]2686, Sept. 12,1994.
74 Business Wire, June 21, 1996.
75 Congressional Record, Vol. 132, E 1516, May 6, 1986.
76 Virginia Pilot (Norfolk), May 16, 1996; John E. Carey, "Ultimate Threat, Ultimate Defense: Navy Has Basics for ABM Defense," San Diego Union-Tribune, March 31, 1996.
77 Congressional Record, Vol. 132, E 1516, May 6, 1986; Business Wire, June 21, 1996. This celebration of its tracking virtuosity leaves out the fact that the Vincennes shot down the Iranian Airbus in 1988. A species of electromagnetic interference involving ducting is known to have played a part. In general, ducting allows electromagnetic signals that normally travel only in straight lines to travel over the horizon. A radar signature from an F14 sitting on the ground at an Iranian airport (that would normally have been beyond the Vincennes's horizon) was suddenly carried by ducting to a Vincennes monitor while other monitors were tracking the Iranian passenger plane at 13,500 feet (Aviation Week and Space Technology, Vol. 129, No. 9 [August 29, 1988], p. 21). Ducting also played a key part in masking the Exocet that hit the Stark in 1987 ("A Tragedy in the Gulf," Newsweek, June 1, 1987, p. 8).
78 Naval Institute Guide to Combat Fleets of the World 1995; see also Friedman, Naval Institute Guide to World Naval Weapons Systems 1997-1998.
79 Kenneth Bacon, Federal Document Clearing House Political Transcript, "Defense Department News Briefing," July 23, 1998. Bacon seemed uncertain of the number, but his uncertainty seems to be not whether there are one or two but whether there are two or more: "one HC-130, and I think it was just two helicopters." News reports immediately following the accident had also specified two helicopters (New York Daily News, July 19, 1996, p. 15). This figure of two persisted until at least December (see, for example, Aerospace Daily, Vol. 179, No. 41, August 28, 1996, p. 306; and Editor and Publisher Magazine, December 21, 1996, p. 40).
80 Friedman, Naval Institute Guide to World Naval Weapons Systems 1997-1998, p. 573. "One recently designed expendable jammer developed in Australia has such high power levels that it can carry out its work even three miles from the plane or ship it is trying to jam (Journal of Electronic Defense, June 1995). But ordinarily they approach much closer to the target craft (what effect does a jammer capable of operating at three miles have when it instead approaches within 200 feet of the target?). Because they are tiny they can approach without being easily seen; their arrival might, however, be accompanied by a streak of light since they are sometimes artillery-fired.
82 Description of US Navy's Cooperative Engagement Capability in Jane's Defence Weekly, April 3, 1996.
83 The USS Normandy was, in fact, at one point scheduled to have her home port in New York City before the controversial Staten Island Naval Station was switched to the Coast Guard and the Normandy moved to Norfolk. "National Defense Authorization Act Fiscal Year 1991," September 11, 1990, Congressional Record, Vol. 136, House, 7297, 7407.
84 Congressional Record, Vol. 140, Senate S1853, February 24, 1994.
85 For examples, see Defense News, June 17, 1996; and Congressional Testimony, April 22, 1997.
86 In fact during this period, one Ticonderoga class Aegis had recently been designated a "Smart Ship" -- a seagoing laboratory for testing new electronic equipment and carrying out unpublished experiments (Defense News, November 13,1995, p. 4; November 20, 1995, p. 2; December 18, 1995, p. 10). Because the Normandy is a Ticonderoga cruiser, it may well have been that laboratory ship. But twenty-six other cruisers are also Ticonderogas; and the testing of new equipment is so extensive that experiments tend to be distributed across many ships.
87 Scheduled for summer 1996 , it was completed in September 1996.
88 Once production reaches the number fifty, our surface fleet of Aegis cruisers and destroyers will together have 5,000 below-deck surface-to-air, surface-to-surface, or surface-to-submarine missile cradles. In summer 1995 and summer 1996 Ballistic Missile Defense Operations Chief Malcolm O'Neill pressed Congress to convert three missile launchers on each Aegis into an Enhanced Launcher Electric System for Theatre Ballistic Missile Defense. We do not know whether these "enhanced launcher electric systems" are the same as the "electromagnetic launchers" that entail high pulse levels, or whether any new launch system was on the Normandy; a fact such as this is just one among hundreds of pieces of information that (however difficult to ascertain from the outside) could be made clear by the men and ,women on board the Normandy itself.
89 Admiral Edward Kristensen, Transcript, "News Conference with Federal Officials." This same information was also given by Defense Department spokesperson Kenneth Bacon, Political Transcript, "Defense Department News Briefing," July 23, 1996.
90 The exercise had earlier been practiced over four populated locations in Europe: Naples, the German interior, the British midlands, and the British coast (Aviation Week and Space Technology, May 5,1975, p. 18).
91 The CIA and NTSB have each constructed a picture of events that may have taken place between the initial second when all the plane's recording mechanisms ceased and second 42 when the satellite recorded a huge explosion. Both agencies picture the plane ascending, the NTSB to 15,000 feet (Public Meeting, December 8, 1997, Morning Session) and the CIA to 17,000 feet (FBI News Conference, November 18, 1997). There exists no radar record of the plane's altitude once it entered the catastrophe; the CIA has cited as evidence of such a climb the sightings of ascending lights by witnesses on the ground who believed they were seeing a flare or missile; it is not clear if there is additional evidence confirming the plane's ascent (which would seem necessary in order to eliminate the possibility that the witnesses actually saw the independent light source they believed they were seeing). The NTSB pictures two explosions, one at or very near the moment the plane's recording mechanisms stopped; the other, the final fireball, at second 40 or 42. The CIA, in contrast, pictures three explosions, one at or near the moment the plane's recordings stop, one at second 20 (just as the plane reaches its highest point of ascent and now turns downward), and the final satellite-recorded explosion at second 42.
The three scenarios that follow do not build the CIA or NTSB trajectories into them; but they can, with slight alterations in phrasing, be adjusted to coincide with the timing and trajectory that have been provided by either of the two accounts. The CIA's belief that explosions occurred at both second 0 and second 20 (in addition to the satellite-recorded explosion at second 42 that everyone agrees about) is compatible with the suggestion made here that the central fuel tank explosion may have taken place from second 0 to second 20.
92 For accounts of the way voltage can "jump" or "leak" from high voltage wires, see The Boston Globe, September 25, 1997, and CBS Evening News, September 25, 1997; and for an FAA account of the way knocking out power in the high-voltage wires can then initiate a surge in the low-voltage wires, see The New York Times, December 12, 1997, p. 20.
93 The coupling of lightning with human sources of electromagnetic emissions occurs not just in the FAA document but throughout the scientific literature. International research on high-power electromagnetics is, according to Carl Baum, comprised of four subjects: nuclear electromagnetic pulse, direct-strike lightning, high-powered microwave weapons, and what are called transient or impulse radars -- radars that use pulses of power lasting less than a billionth of a second in order to achieve high resolution ("From the Electromagnetic Pulse to High-Power Electromagnetics," pp. 789, 800-801). Baum writes, "For the most part the different environments (EMP, lightning, HPM) interact with complex systems [ship, missile, aircraft, tank] in the same way" (p. 802). The similarities among all types of "big, fast electromagnetic fields, currents, voltages" (p. 789) is a point returned to at key points in the article, and an extensive bibliography provides studies comparing any two of the four (such as lightning and EMP).
In 1981 the International Union of Radio Scientists -- called URSI or Union Radio Scientifique Internationale -- founded a working group on problems of electromagnetic compatibility called Commission E. It examines interference from both natural (lightning) and technological sources (e.g., electromagnetic launchers) on power lines, aircraft, spacecraft, or other accidental targets.
94 One physicist suggests that electromagnetic energy from the external environment could enter the plane at apertures in the wings and travel along a metal fuel line passing inside the central fuel tank; this could cause a spark within the tank if the line were not sufficiently grounded at one end or the other.
95 In the introduction to his classic papers, Electric Waves, published in 1890, Heinrich Hertz repeatedly stresses the role of sparking in initiating his own discoveries. The opening four pages are a sustained celebration of "a special and surprising property of the electric spark which could not be foreseen by any theory." Heinrich Hertz, Electric Waves Being Researches on the Propagation of'Electric Action with Finite Velocity Through Space, translated by D.E. Jones, with an introduction by Lord Kelvin (Dover, republication of 1893 edition), pp. 2, 3, 4. The sparks in Hertz's experiments (which take place in a room 15 meters long) occur not just at the site of transmission but the site of reception (a looped antenna or secondary conductor) placed at distances ranging from 5 to 10 meters from the transmitter. For an account of the spark at the site of reception, see also Hugh G. J. Aitken, Syntony and Spark: The Origins of Radio (Princeton University Press, 1985), especially pp. 54-58.
96 According to Jane's Aircraft Upgrade (p. 313), a fly-by-wire system became available to the 747-100 starting in 1982: a Performance Management System "calculates, displays, and controls automatically the optimum or desired airspeed, engine power setting, altitude and flight path of the aircraft." On Boeing's celebration of the 747-100's high-tech profile on its twenty-fifth birthday, see "Boeing 747 Celebrates Twenty-Five Years in Service," PR Newswire, January 19, 1995. The presidential plane, Air Force One, is a 747-200, a model first flown in 1970 and therefore one with analog equipment. As was mentioned earlier, it has been highly shielded against electromagnetic interference. If analog equipment is immune, such shielding would seem unnecessary. Information about the combinations of analog and digital equipment on Air Force One and the country's Command Post A-4s might be useful in assessing TWA 800's own level of immunity.
97 Evidence that equipment combining analog and digital equipment is not wholly immune is provided by the Black Hawk helicopter. It had a combination of mechanical and fly-by-wire systems during the 1980s (Aviation Week and Space Technology, Vol. 129, No. 14 [October 10, 19881, p. 75), the period during which it suffered the interference problems described by Colonel Quisenberry and other military spokesmen. "Friedman, Naval Institute Guide to World Naval Weapons Systems 1991-1992, p.230.
99 Shooman, "Occurrence Rates," pp. 4, 6, 8.
100 Cockpit Voice Recorder, National Transportation Safety Board, Washington, D.C., Docket No. SA516, Exhibit 12-A.
101 According to the Flight Data Recorder (National Transportation Safety Board, Docket No. 5A-516, Exhibit 10-A), the values recorded for the wing flaps (called ailerons) were 64 noisy and erratic" at some moments during the last five minutes of flight. But the NTSB report also notes that "anomalous values" are not uncommon on flight data recorders.
102 International Defense Review, Vol. 28, No. 12 (December 1, 1995), p. 9.
103 Jane's Navy International, Vol. 101, No. 9 (November 1, 1996), p. 21.
104 "Lockheed Martin Aeronautical Systems," Flight International, October 23, 1996.
105 "Australian Troops Mourn Victims of Helicopter Crash," Reuters World Service, June 14,1996.
106 As noted earlier, Commission E of the International Union of Radio Scientists (URSI) each year convenes to discuss the way electromagnetic signals from radars, high-frequency radio, lightning, and microwave weapons can interfere with the operation of airplanes, spacecraft, analog circuits, and power lines. The papers are delivered and listened to by physicists, electrical engineers, and radio astronomers from many different countries.
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