The following correspondence took place between Elaine Scarry, author of “The Fall of TWA 800: The Possibility of Electromagnetic Interference,” published in the April 9, 1998, issue, and James E. Hall, Chair of the National Transportation Safety Board.
March 13, 1998
James E. Hall, Chair
The inquiry into the fall of TWA 800 on July 17, 1996, has centered on three areas: a mechanical accident, a bomb, and a missile or other high-velocity material object (such as a meteorite). Arriving in your office tomorrow morning is an article in The New York Review of Books that will reach the public next week. It describes a fourth possibility: electromagnetic interference from one or more of the ten military craft that were in the area. The article asks that this matter be taken up by the NTSB.
Prior to its publication, the article was read by many experts: electrical engineers, physicists, specialists in avionics and aerodynamics, pilots, several people in the Navy or Air Force. Among them are people with specific expertise in either electronic warfare or electronic interference.
The article is divided into three parts. Part 1 gives a portrait of High Intensity Radiated Field events and shows the efforts made by the military to protect their own craft against inadvertent radio interference from other military craft. Military planes spend more time in the company of other military craft than do civilian planes, and are therefore more likely to be subjected to a High Intensity Radiated Field event. But civilian planes do sometimes (as in the case of TWA 800) end up in the vicinity of military planes or ships; they may, therefore, sometimes be placed at risk. A NASA report that determines occurrence rates of HIRF accidents is included, as are other materials (an FAA document, a statement by Raytheon’s president) to show why inquiries into the unsolved crashes of civilian planes need to look at this possible source.
Part 1 of the article urges that military studies of electromagnetic interference—such as the seven-month study by the Air Force in 1988 and the three-year Pentagon study in 1989-1991—be made available to the NTSB for its continuing inquiry into TWA 800. This request is compatible with your own insistence during the Public Meeting in Baltimore, December 8-12, 1997, that military and civilian worlds need to share research about aviation safety. You are quoted at length on this key matter on page 63 of the article.
Part 2 of the article moves from the background to the foreground. Ten military craft were in the vicinity of TWA 800 at the time it began its fall: one P3 Orion, one C-130, one Black Hawk helicopter, one C-141, one C-10, the Coast Guard cutter Adak, the USS Wyoming, the USS Albuquerque, the USS Trepany, and the USS Normandy. The section examines five of these craft in order to provide a sample of the questions that need to be asked of them all. It specifies the kinds of sophisticated electromagnetic equipment included on such craft. It also indicates the many pieces of information about these craft that have not yet been made available either to the public or to the NTSB. The article urges that a detailed picture of the electronic equipment that was turned on and turned off that night be provided to the NTSB. It also argues that the airmen and sailors themselves (not one of the Chiefs of Staff or the Commander of the Second Fleet) are the people who can best provide the concrete information needed for a minute-by-minute reconstruction.
Part 3 of the article brings the background research on HIRFs together with information known about the fall of TWA 800 to suggest three possible ways in which electromagnetic interference might have played a part in the crash. The scenarios represent just three of many possible paths that a HIRF accident conceivably could have taken. The section draws on the research completed by the NTSB.
Also included in Part 3 are statements on the need for a public inquiry. The statements are made by Rear Admiral (retired) Eugene J. Carroll, Jr., Deputy Director of the Center for Defense Information; physicist and electrical engineer D.V. Giri, a former research associate at Phillips Laboratory, Kirtland Air Force Base, and a designer of both antennas and filters for microwave systems; Martin Shooman, the author of the NASA study on occurrence rates of HIRFs as well as other studies of aircraft and satellites and a book on Probabilistic Reliability; a physicist deeply knowledgeable about electronics; and David Wunsch, electrical engineering professor at University of Massachusetts-Lowell, who for many years has researched radios and antennas. These people (as well as others whose written research is cited in the article) might be useful participants in any NTSB inquiry into electromagnetic interference.
I am unaware of any findings by the NTSB that would rule out the possibility that a High Intensity Radiated Field event played a part in the crash of TWA 800. Since April 1997, when I began the study, all information released to the public by your agency has appeared to me either neutral or positive with respect to the thesis that electromagnetic interference from an external source may have played a part. This includes, for example, your emphasis, beginning in July 1997, on the need to find an electrical source for the ignition of the central fuel tank, and the revelation that it has so far been difficult to find any conclusive source inside the plane itself.
The article stresses the fact that the inquiry into the possibility of a HIRF accident needs to be carried out by the National Transportation Safety Board (and not, for example, any other government body such as the FBI or CIA). The NTSB is the duly constituted agency for such an inquiry and represents not just those who have been directly harmed by the accident but the citizenry as a whole.
Let me add to what the article says by mentioning how impressed I was by your respect for citizens—for their obligation to keep themselves informed about such an event—throughout the December 8-12 public meeting. I refer in part to your insistence that civilian and military realms must more fully work together to ensure everyone’s safety. But I also refer to your continual awareness of what someone looking at one of your graphs or listening to one of your experts might not yet understand. No sooner did a question arise in my mind (“What does ‘30 knot target’ mean?”) than I would hear your voice interrupting the proceedings to ask, “What does ‘30 knot target’ mean?”
I hope the NTSB’s inquiry will continue to give voice to matters that are of wide concern. Should you have any response to the article, I would be most eager to learn of it, as would Robert Silvers of The New York Review, which would welcome a response from you.
Sincerely,
Elaine Scarry
Cambridge, Massachusetts
April 21, 1998
James E Hall replies:
Dear Ms. Scarry:
Thank you for your March 13, 1998, letter regarding the National Transportation Safety Board’s investigation of the accident involving TWA flight 800. In your letter, you provided a summary of your article in The New York Review of Books regarding the possibility that electromagnetic interference (EMI) or High Intensity Radiated Fields (HIRF) could have caused the accident.
I have read your article and found it quite interesting. The Safety Board’s investigative team has considered the possibility that EMI or HIRF was a factor in the accident and has been actively pursuing the events that could have led to the ignition of the fuel/air mixture in the center fuel tank. The investigative team is working with private contractors and the military to determine the effects of EMI or HIRF on Boeing 747s.
If EMI or HIRF had ignited the fuel/air vapor, other systems on the TWA flight 800 airplane would have also been affected to some degree. The examination of the flight 800 flight data recorder and the cockpit voice recorder did not indicate any unusual signals before the end of the data. Additionally, it would be unusual if only one airplane operating in the area was affected by EMI or HIRF. The flightcrews of other airplanes operating nearby did not report any problems with their airplanes. These are just a few of the issues that will be addressed as we continue our investigation. However, please be assured that the Safety Board is considering every possible event that could have led to this accident, including EMI or HIRF.
Once again, thank you for sending me a copy of your article.
Sincerely,
Jim Hall
April 30, 1998
Dear Chairman Hall:
I write to thank you for your letter of April 21, responding to my article in The New York Review of Books and my March 13 letter to you. I am glad to learn that the problem of High Intensity Radiated Fields (or High Intensity Radio Frequency as it is alternatively called) is a subject included in the TWA 800 inquiry.
In your letter you name two features of the crash that you believe diminish the probability that HIRF was the cause. I hope before long to write you a letter about these two matters: the first, the question of whether other planes in the area reported any signs of electromagnetic interference; the second, the question of whether the voice and data recordings on TWA 800 contain any sign of interference.
For the present I wish simply to express my gratitude for your attention to the subject of my letter and article. I also have one pressing question. You state, “The investigative team is working with private contractors and the military to determine the effects of EMI or HIRF on Boeing 747s.” Is it possible to give an idea of the time period you anticipate will be involved in this research? Is it (for example) more likely to be several weeks or instead a year-long project? If you have even a very rough idea about the timing, I would be grateful to know it.
Sincerely yours,
Elaine Scarry
May 27, 1998
Dear Ms. Scarry:
Thank you for your April 30, 1998, letter regarding the National Transportation Safety Board’s ongoing investigation of the accident involving TWA flight 800. In your letter, you ask about the time that will be required for research into the possible effects of High Intensity Radiated Fields (HIRF).
The Safety Board has several energy-related activities in progress. The examination of energy induced by one aircraft system into other aircraft systems began in 1997, and more than half of the planned tests have been completed. Work is also underway to examine threats that may have resulted from an external surface or airborne HIRF source. This is a challenging undertaking that involves an understanding of military emitters, as well as a considerable number of civilian transmitters near the accident site.
