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Holding the Government Accountable

Tripwired? Document Trail of Faulty Airplane Wiring Demonstrates Need For Comprehensive Review

Why Does This Issue Matter?

Aircraft manufacturers have downplayed the significance of these wiring problems in commercial aircraft and the military has remained silent. To compound the problem, more than 2,500 commercial aircraft in the United States may soon be flying beyond their original design life, thereby increasing the danger of wiring and electrical problems. Examples of wiring failure-related incidents abound. For instance, faulty wiring is a prime suspect in the explosion of TWA Flight 800 in 1996. Furthermore, shortly after the 1996 crash of ValuJet 592, a maintenance worker for ValuJet reported to the FAA that wiring on that plane was notoriously bad and had suffered numerous cracks and shorting out. The documented history of known electrical problems and failed wiring, combined with recent FAA and National Transportation Safety Board (NTSB) action on specific wiring problems, (points to the need OR calls) for immediate broader action.

POGO's report was issued as flammable wires were discovered in commercial airlines and the Federal Aviation Administration (FAA) ordered the grounding of Boeing 737s.


The Project On Government Oversight (POGO) is a non-partisan, non-profit organization that, since 1981, investigates, exposes, and remedies abuses of power, mismanagement and subservience to special interests by the federal government.

Our methods include networking with government investigators and auditors whose findings have received little attention, working with whistleblowers inside the system who risk retaliation for exposing waste and fraud themselves, and performing independent investigations into areas we suspect are problematic. Often we are not "experts" in the field of our investigation - which is why we provide extensive documentation. POGO believes in getting the truth out, by shining light on the facts and letting the documents speak for themselves.

Executive Summary

  • Following discovery of electrical arcing from chafed wires, the Federal Aviation Administration (FAA) has ordered grounding of Boeing 737 aircraft and immediate wiring inspections.
  • Military and industry documents show that wiring problems may be much more widespread than just the issue of chafed wiring in the wing fuel tanks of 737 aircraft. Wire insulation failures - cracking, crazing, nicks spreading 360 degrees around the wire, high flammability, toxicity, softness at high temperatures - have been discovered in the past even without chafing.
  • The military has been aware of serious wiring problems on its aircraft since at least the early 1980s. Problems were found not just with chafing, but also with degeneration of the insulation surrounding wires. Cracking of insulation was causing sparks and electrical problems.
  • Faulty wiring is a prime suspect in the explosion of TWA Flight 800 in 1996. That aircraft had a type of wire, Poly-X, that the military partially replaced on Navy F-14 aircraft due to cracking. The aircraft also had another type of wire, extruded Teflon, going into the fuel tanks. The manufacturer had discovered cracks in this type of wire over a twelve year period.
  • Following the crash of ValuJet 592 in May 1996, a maintenance worker for ValuJet reported to the FAA that wiring on the DC-9 that crashed was notoriously bad and had suffered numerous cracks and shorting out.
  • A new-technology wire that has tested far better than the older types of wire is still not the standard wire specified in military specifications or FAA standards.
  • A Defense Department wiring expert who raised the issue of faulty wiring on military aircraft in the early 1980s was retaliated against and fired.
  • The government needs to initiate a comprehensive, high-level review of problems with wiring in both military and commercial aircraft to try to identify, at a minimum, the worst trouble spots.
  • To prevent these kind of problems from escaping sufficient scrutiny in the future, improved information and investigation sharing are needed between the FAA and NTSB, on the one hand, and the military services on the other. More funding is needed for FAA inspectors, and the military should stop keeping its accident safety investigations secret.
  • Protections should be improved to prevent bureaucracies from retaliating against those of their employees who speak out to try to fix a problem, and to encourage the agencies to listen to the message rather than shoot the messenger.

Specific Fixes, But A General Problem

In the last week, the Federal Aviation Administration (FAA) issued an urgent directive that older Boeing 737s must now have their wing wiring inspected immediately, and gave 60 days for the inspection of wiring in 747s and 767s. Over the past few months, the FAA issued directives requiring inspections and wiring fixes in 737s and 747s. Yet according to government and industry documents, the military has long known about inadequate wiring and its potentially catastrophic consequences - wiring that is still found on these and other commercial and military aircraft flying today. This wiring is found throughout the aircraft, not just in the wings. Aircraft manufacturers have downplayed the significance of these wiring problems for commercial aircraft.

This documented history of known electrical problems and failed wiring, combined with recent FAA and National Transportation Safety Board (NTSB) action on specific wiring problems, calls for immediate broader action. The government needs to look at faulty wiring as a major problem, not just a matter for fixes limited to specific problems in 737 wings.

Broken or cracked insulation on wiring, creating sparks or incorrect electrical signals, has already caused a variety of electrical problems gravely endangering aircraft in flight. Arcing from wires with broken insulation can burn holes through nearby metal. Some Boeing aircraft have had in-flight electrical problems with autopilots and cargo doors.1 Although the NTSB has not yet formally issued final conclusions from its investigation of the explosion of TWA Flight 800 in July 1996, faulty wiring remains a prime suspect. In the interim, the NTSB has urged wiring inspections. One ValuJet whistleblower's description of faulty wiring on ValuJet Flight 592 following its crash into the Florida Everglades, raises serious concern about the state of aircraft wiring and the possibility that it may have played a role in that accident.

Some wiring problems may be caused by physical chafing, often from vibration, that would split even wires whose insulation was otherwise acceptable. But both cases of wiring failure are wiring issues needing more attention.

On the military side, wiring problems were so severe in the 1980s on the Navy's F-14 fighter - at one point F-14 crashes due to various causes were so high that Congressional hearings were held2 - that many aircraft had to be partially rewired or taken out of service.3

The numerous electrical "anomalies" and unexplained crashes that aircraft have suffered often cannot be decisively proven to be caused by wiring problems - as many people who have experienced hard-to-track-down electrical problems in their automobiles can appreciate. Most wiring failures do not lead to crashes, since not all wiring is crucial to flight control systems or fuel tank safety. But the potential for disaster is always there, and will only get worse as aircraft age - two years from now more than 2,500 commercial aircraft in the United States may be flying beyond their original design life.4

Despite a record of years of electrical problems, and knowledge that wiring with identified problems is still found on many commercial and military aircraft, the government has yet to review comprehensively the track record of wiring types and acknowledge the potential scope of wiring hazards. The FAA has begun to look at wiring issues more, but an accelerated, government-wide initiative is needed. Information sharing between the FAA, NTSB, and military agencies can and should be expanded to improve prevention of air accidents.

The White House Commission on Aviation Safety and Security urged expanded FAA action on wiring in its 1997 final report. The report drew a parallel between the earlier overdue action on potentially catastrophic "structural" failure in aircraft, and current sluggishness on wiring and other "non-structural" areas. Warning signs on structural problems were not caught by normal maintenance and oversight - it took part of a Boeing 737 aircraft's shell ripping off in flight to spur adequate action on structural failures. Compared to structural issues, the Commission said, ". . . much less is known about the potential effects of age on non-structural components of commercial aircraft," including "electrical wiring; connectors, wiring harnesses, and cables. . . ." Despite industry optimism, the Commission was:

concerned that existing procedures, directives, quality assurance, and inspections may not be sufficient to prevent safety related problems caused by the corrosive and deteriorating effects of non-structural components of commercial aircraft as they age.5

Unfortunately, wiring problems might have received earlier and greater attention from government agencies if the initial reaction to "the messenger bearing the bad news" had been to listen rather than retaliate. After former Pentagon whistleblower Ed Block long ago raised the danger posed by certain wires on military aircraft - as part of his job as a wiring expert for the Defense Industrial Supply Center - he was fired.6 The troubled wires he spotted in the early 1980s are still on aircraft, and one of their inadequate successors is still being put on aircraft.

Commercial Aircraft Wiring Problems - From Disturbing Incidents to Catastrophes?

Cracked wiring causing short circuits or sparks is a prime suspect in one recent commercial aircraft disaster, and raises dire warnings in another:

  • The National Transportation Safety Board (NTSB) has yet to release its final report on the TWA 800 mid-air fuel tank explosion, but based on its investigation to date has urged the Federal Aviation Administration (FAA) to order inspections of wiring not just in Boeing 747 fuel tank wires but also wires on some Boeing 727, 737, 757, and 767 aircraft. (See Appendix A). The FAA has recently issued limited directives to re-inspect, shield, and separate certain wires on Boeing 737 and 747 aircraft. (See Appendix B). Long before the TWA 800 crash, a Boeing 737 sharing similar fuel system wiring suffered a catastrophic fuel tank explosion on May 11, 1990 in the Philippines.
  • The NTSB concluded that the cause of the fire on ValuJet 592 was self-ignition of oxygen canisters in the cargo hold.7 But an anonymous whistleblowing ValuJet maintenance worker called the FAA and described extraordinary wiring problems on the aircraft that crashed, including multiple electrical failures and shorting wires in the days leading up to and the day of the crash. (See Appendix C). Five days after the ValuJet crash, FAA released a directive - months in preparation - requiring inspection of cockpit wires "to prevent the potential for fire and uncontrolled smoke throughout the cockpit due to damaged electrical wiring."8

The whistleblower claims in the telephone call record that he and other ValuJet workers knew that Flight 592 aircraft ". . .904's wiring was notoriously bad" and that ". . . any wire bundles that had to be moved would cause the wires to break and short out." Circuit breakers on the aircraft had been bypassed. As homeowners know, circuit breakers are vital to prevent electrical fires.

Whether or not wiring was a part of the problem, at a minimum these astounding allegations raise serious questions about the condition of aircraft wiring, maintenance violations in the airline industry, and adequacy of oversight. At worst, the revelations could mean that wiring was the chief crash culprit, and escaped notice. The FAA reported the allegations to the NTSB, but normally the NTSB would not spend resources trying to track down an anonymous whistleblower. In this case the NTSB stated that it did check circuit breakers on other ValuJet aircraft but did not find more bypassing.9 The whistleblower's allegations were not directly addressed in the NTSB final report.

Problems have been discovered on various types of wire used on commercial and military aircraft. Particular wires mentioned here serve to illustrate the potential scope of the problem, but other wires may be troublesome too. Poly-X, a wire called "miserable" by military maintenance specialists, was originally installed on many Boeing 747s - including TWA 800 - and McDonnell Douglas DC-10s, another jumbo jet.10 (See Appendix D).

TWA 800 also had another wire type going into its fuel tank called extruded Teflon, which was meant to carry only low-voltage current. Meeting minutes attached here in Appendix E reveal that - as long ago as the early 1980s - Boeing itself said that it had experienced cracking problems over a twelve year period with extruded Teflon. Yet the wire was still on TWA 800. Since it usually takes a chain of events to cause a crash, cracking in just one wire type would be less likely to cause a fuel tank explosion. But cracking in two wire types - hypothetically, Poly-X and extruded Teflon - could allow high voltage electricity to jump to low voltage fuel tank wires and cause an explosion.

Documents show that the military was aware of very serious problems with Poly-X and some of its successors, yet Boeing and McDonnell Douglas have argued that the wires' problems are not serious. (See Appendix F). It would be prohibitively expensive to replace all the questionable wiring on commercial aircraft, since it is hard to access in many places, so aircraft manufacturers and airlines have an interest in keeping the old wiring in place. However, a comprehensive review of all wiring problems could identify more of the crucial weak spots that could be selectively fixed. In theory, it might be less costly for an airline to do more fixes now rather than have more aircraft crashes.

Military Aircraft Wiring Problems - Been There, Done That

Poly-X was used on many military aircraft in the 1970s and 1980s, including on F-4s, E-2s, S-3s, A-6s, and F-14s. The company that produced it, Raychem Corporation, was the ". . . sole source QPL. [Qualified Products List] supplier of virtually all airframe wire used by the military . . ."11 at one point in the mid-1970s. The Navy requested $354 million to fix the problems it found with the wire. The budget justification document reported that:

Numerous wiring harnesses made of "POLY-X" wire have had an abnormal insulation aging, embrittlement and cracking resulting in wire-to-wire shorts, particularly during the presence of water.... Some of the wire and connector failures have been observed as spurious signals on control wires causing spoilers to stick in the up position, inadvertent autopilot commands and power shorts which disable the autopilot completely. (See Appendix G).

An independent industrial committee investigating the issue found:

Flight-ready aircraft that were wired with Poly-X wires exhibit very frequent radial splits and cracks in every location where observed on F4, A6, E2C and F14 aircraft. These insulation splits usually expose the conductor and severe conductor corrosion is found. . . . Harness and wire bundles have or contain severely cracked Poly-X wire along with unaffected Kapton insulated wire. (See Appendix H).

While admirals described "significant maintainability problems and a reduction in combat readiness due to Poly-X wiring" (See Appendix I), Navy aircraft maintenance workers summed it up simply: "Poly-X sucks." (See Appendix J).

Faulty wiring in aircraft has caused other serious problems besides just fuel tank explosions. A six month study in the 1980s found 800 autopilot malfunctions on KC-135 tanker aircraft, equivalent to the commercial Boeing 707, which were wired with a PVC type wire different than Poly-X. (See Appendix K). Full rolls of the aircraft to left or right while on autopilot were found to be "due to broken wires." A one-time inspection discovered that almost a quarter of the aircraft had faulty wiring. In November 1997, Air Force One - at the time a Boeing 707 variant - carrying First Lady Hillary Rodham Clinton on a trip to Asia had to conduct an emergency landing after frayed wiring caused warning lights to come on.12 Many KC-135s, other military 707 variants, and 707s in commercial service are still flying. Again, commercial incidents echoed military ones: a 1992 uncommanded roll while on autopilot caused a cargo 747 to dive 10,000 feet. The problem was caused by stray electrical signals, a hallmark of faulty wiring. The NTSB asked Boeing to redesign the autopilot system.13

Raychem replaced Poly-X with another wire, Stilan, but it also had problems and production was terminated. (See Appendix J and Appendix O). Then yet a third product produced sole-source by Raychem Corporation, Raychem 55, was declared in various Military Specifications as the preferred or only wire to use, and has been put in new military aircraft ever since. But Raychem 55:

  • has some of the same cracking problems as Poly-X (See Appendix J).
  • is excessively flammable, smokes very badly (See Appendix L).
  • and is toxic when it burns (See Appendix M).

Apart from safety concerns, a problem with Military Specification 5088's leading to use of Raychem 55 is that the wire is a sole-source product, limiting the government's ability to shop around. In one application Raychem was quoting the government $31.00 per foot for Raychem 55, versus the $1.40 price of another wire that was found to be a "totally acceptable" substitute. (See Appendix N and Appendix O).

A memo from the Defense Industrial Supply Center, an agency that supplies materials to the military services, charged that "There are strong indications that Government personnel may be directing procurement to Raychem 55," suggesting they were skewing the procurement process, including writing military specifications so that Raychem 55 would be bought instead of superior products. (See Appendix N).

Government and industry have jointly developed a new wire called composite Teflon-Kapton-Teflon wire that shows far superior results than Raychem 55, according to various studies, including a comprehensive report by McDonnell Douglas and the Air Force, yet commercial specifications have not been re-written to encourage use of the improved product. (See Appendix L).

Systemic Failures - A Threat Not Fully on the Radar Screen

Systemic problems may help explain why wiring problems have not received the full attention they appear to have needed over the past two decades. The biggest problem may be that the FAA and NTSB on the one hand, and military agencies on the other, have not communicated and shared data with each other sufficiently. Not only are some aircraft in use in both commercial and military fleets, but components such as wiring are shared too. If both sides do not have a full set of information, one or the other will be missing key information.

Similarly, information-sharing between the military and aircraft manufacturers could be improved. Boeing noted that it was ". . . not aware of any requirement or procedure for the DOD to notify us of problems experienced on aircraft not manufactured by Boeing" - even though wiring trouble could be spotted on other manufacturers' aircraft using the same type of wiring as Boeing. (See Appendix F).

A related problem is that the military does not normally release its full safety investigation reports, merely its legal assessments, which do not include all the information in the safety investigation. Defense Secretary Cohen recently spoke favorably about releasing more investigation results.14 With secret investigations, it is particularly hard to assure the adequacy of the investigations and apply their lessons elsewhere. Senators Ron Wyden (D-OR) and Gordon Smith (R-OR) had to go to the extreme of holding up the confirmation of a new Chairman of the Joint Chiefs of Staff in order to get the Air Force to re-open a C-130 crash investigation that it had closed without a conclusion.15 The Senators also had to bring great pressure to get the Air Force to break precedent and cooperate with outside NTSB investigators. The C-130 has experienced 71 in-flight total engine shutdowns, almost half of which had an "unknown" cause in closed investigations, and 24 of which were attributed to the electrical system.16

In a rare instance, the Air Force did permit the NTSB to lead the investigation of the CT-43A that crashed with Commerce Secretary Ron Brown and his delegation on board in 1996. The Air Force CT-43A is equivalent to a commercial Boeing 737. But the Air Force only cooperated after deciding that "the NTSB had both superior expertise in this particular aircraft and also a compelling interest in discovering whether factors in the CT-43 crash could resolve the cause of [commercial 737 crashes]."17 This cooperation and sharing of years of experience on both sides can and should be fruitfully expanded.

NTSB and FAA crash expertise may be particularly useful because pilots and line officers who are not dedicated crash experts often lead Air Force crash investigations, according to a former Air Force safety official and NTSB investigator, Alan Diehl. Diehl has even called for independent investigations of military accidents: "Nobody should be allowed to investigate themselves, [and] certainly [not] the Defense Department. . . . Investigators need to be independent of the people they are investigating."18

Remedies - Ways to Bring Focus on This Issue, and to Share Government Resources Better on the Next Issue

Some might ask, if wiring is such a problem, why aren't we seeing more aircraft crashes? The short answer is that it usually takes multiple failures to bring down an aircraft, some level of redundancy is built into most aircraft. But the real answer is that if you are a passenger on any plane "tripwired" with faulty wiring, that's one faulty wire too many. The government needs to improve assessment of the potential dangers posed by wire failures. Systemic failures that have allowed wiring to escape sufficient scrutiny suggest the following remedies:

  • Acknowledge the potential scope of the problem. In order to gain high-level focus and to bring together government-wide experiences, coordinate action on wiring issues in one office.
  • Conduct an immediate, government-wide, joint FAA, NTSB, and military assessment of wiring problems, correlating all commercial and military crashes, electrical "anomalies," and maintenance findings with data on which aircraft wires are where. This could help find, at a minimum, the worst trouble spots. Conduct complete teardowns of various aircraft to develop a representative but thorough picture of the state of wiring in aircraft.
  • Develop procedures for increased sharing of accident information between the military and the FAA and the NTSB.
  • Conduct joint NTSB/military investigations of military crashes and include more crash experts in military investigation teams.
  • Reverse the decline in FAA training funding. The General Accounting Office has reported that "Our work has shown persistent problems with FAA's training of inspectors. Specifically, inspectors have been unable to take courses that they believe are necessary to perform their inspection responsibilities. . . . Decreases in FAA's overall budget have reduced the funding available for technical training by 42 percent from fiscal years 1993 through 1996."19 Increase funding for FAA training and, specifically, expand training of government accident investigators from all agencies in wiring issues.
  • Release the full results of military accident investigations, and allow for independent review of findings.
  • Update FAA standards in the Code of Federal Regulations and modify Military Specifications quickly to meet the superior performance standards of the latest composite wire.
  • Improve procedures to prevent retaliation against whistleblowers or those trying to fix a problem from the inside.


WIRES Military specifications can be written so that they refer to only one product. The digits after the slash can distinguish one product from another.

Extruded Teflon MIL-W-16878/5-EE Wire used in some Boeing fuel tanks.
PVC wire - Wire used in DC-9 cockpits such as ValuJet 592. FAA required inspections of the wiring because of fire danger. Also in military Boeing KC-135s.
Poly-X MIL-W-81044/16 through -/19 Found to be faulty on military aircraft and partly replaced; still on commercial aircraft. Raychem product.
Stilan MIL-W-81044/20 Raychem product
Raychem 55 MIL-W-22759/32 through -/35 Raychem product, also called modified Tefzel, or cross-linked (irradiated) ETFE; still being used in new aircraft
Kapton MIL-W-81381/1-6, and -/12 Dupont product; an improved Kapton was also produced
hybrid, composite, or Teflon-Kapton- Teflon - New wire with superior smoke, flammability, mechanical properties
NTSB National Transportation Safety Board The federal agency that investigates the causes of aircraft accidents. It issues recommendations to the FAA and other agencies to improve safety, but does not have enforcement ability, nor is the FAA required to accept its recommendations. Historically, the FAA has accepted only 83% of NTSB recommendations.
FAA Federal Aviation Administration The federal agency that regulates the aircraft and airline industries.


Appendix A: Washington Post Article on National Transportation Safety Board Wiring Recommendations, April 8, 1998. Article reports that NTSB urges inspection of wiring on not just Boeing 747s and 737s but also various 727s, 757s and 767s.

Appendix B: FAA Press Releases on Boeing 747 and 737 Wiring, November 26, 1997 and April 16, 1998. Proposed FAA directive on 747s calls for inspection of wiring and installation components to prevent electrical spikes or short circuits around fuel systems. Proposed FAA directive on 737s calls for installation of electricity suppressors, shielding, and separation of wires to prevent electricity jumping to fuel tank wiring.

Appendix C: Federal Aviation Administration Description of a Telephone Call from ValuJet Anonymous Whistleblower, as Reported to the National Transportation Safety Board, May 14, 1996. ValuJet maintenance worker reports electrical problems and dangerous procedures performed on the ValuJet Flight 592 DC-9 that crashed. The revelations raise questions about the NTSB's determination that oxygen canisters self-ignited.

Appendix D: Tables from a Commercial Wiring Distributor Illustrating Which Wire Types Are on Which Commercial Aircraft, 1991.

Appendix E: Minutes of A Society of Automotive Engineers Industry/Government Subcommittee Meeting, February 2, 1983. Years before the TWA 800 explosion, a Boeing official states that Boeing has had cracking problems with extruded Teflon wiring. Extruded Teflon wiring was used for low-voltage fuel tank wiring in TWA 800.

Appendix F: Letters from Boeing and McDonnell Douglas to NTSB on Raychem Corporation Wiring, July 18, 1995 and July 20, 1995.

  • Boeing states they do not have safety concerns with the wires, page 2.
  • Boeing notes high wire-to-wire abrasion in some Poly-X wiring, but does not blame the wire specifically. Minor deterioration on Stilan in tests noted, page 2.
  • Boeing mentions there was no procedure for DOD to notify Boeing of problems not on Boeing aircraft, page 3.
  • McDonnell Douglas states it believes the wires are suitable, page 2.
  • McDonnell Douglas notes chafing problems with Poly-X and a service bulletin for replacement of affected wiring, page 1.
  • McDonnell Douglas notes Poly-X insulation failure due to overstamping, causing a fire, but does not blame the wire specifically, page 2.

Appendix G: Navy budget document from request to Congress for funds, FY 1983. This document shows that the Navy found problems with Raychem's Poly-X.

Appendix H: National Electrical Manufacturers Association Report on Military Aircraft Wiring 1982. This report followed a NEMA study team visit to Navy repair facilities where they interviewed maintenance specialists and examined aircraft. The document includes:

  • severe problems experienced by Poly-X, including frequent splitting (see especially Subsections 5.c, and 7.d, page 4).
  • Subsection 1.d on page 5 notes that wire was replaced with the same kind of wire - more Poly-X.
  • Problems with Raychem 55 were also discovered (see especially Section 9, page 5) by the team.

Appendix I: Navy Letter to Congress on F-14 Poly-X Wiring Problems, June 2, 1997.

  • Notes that 323 F-14s had Poly-X wiring, Para.4.
  • Notes that Poly-X caused maintainability and readiness problems, necessitating replacement of critical wires, sometimes with Raychem 55, Para. 3.
  • Claims there is no documented F-14 safety wiring problem any more, Para. 8.

Appendix J: National Electrical Manufacturers Association - Site Visit Notes July 26, 1982.

  • The document notes problems with Raychem 55 at page 5, Section 3. Naval air rework facility personnel are recorded as saying that they were directed to use Raychem 55 despite their preferring another wire.
  • At page 5, Section 4 the document reports that Raychem 55 wire used for fuel tanks had corroded shielding and cracked insulation "as received" from the factory, before it had even been put on aircraft.
  • At page 5, Section 2, severe problems with another Raychem wire, Stilan, are noted.
  • At page 3, Section 1, a maintenance worker view of Poly-X is noted. In order to use up large stocks of Poly-X, broken Poly-X was replaced with more Poly-X.

Appendix K: Air Force Briefing on Studies of Wiring Problems in KC-135 Aircraft, Covers 1981-85.

  • 800 autopilot malfunctions.
  • 23% of aircraft had faulty wiring.
  • Wiring unreliable, fraying, deteriorating, and overheating.
  • Wiring shorts cause electrical problems.
  • Over 8000 wiring defects found in a three-year period.

Appendix L: Letters from Tensolite Company, May 24, 1996 and April 15, 1997

  • Letter to David Hinson, FAA, notes dangers of Raychem 55 (Mil-W-22759/34) and that it is still used, page 1.
  • Cites independent studies showing new hybrid wires superior to Raychem 55, page 2.
  • Letter to Ed Block, former DOD wire expert, notes Raychem 55 (BMS 13-48) found on a wide variety of aircraft including helicopters, private jets, and shorter-range commercial aircraft too, page 1.
  • Calls for updating FAA standards to new performance capabilities, page 2.

Appendix M: Conversation Record, Defense Industrial Supply Center and Grumman Aerospace March 17, 1983.

  • Memo notes that Grumman decided not to use Raychem 55 due to the results of toxicity tests.

Appendix N: Defense Industrial Supply Center Memo on Aircraft Electrical Wire August 31, 1982. This memo was written to halt the adoption of Raychem 55 as the preferred wiring under certain military specifications. It documents:

  • problems with Raychem 55 - called "Raychem (Modified Tefzel)" on Enclosure page, and 1.b(3) on page 2,
  • the high cost of Raychem 55, Section 1.b,
  • cracking and crazing problems with Stilan as well as Poly-X, Section 1.b(1),
  • that in 1982, 80-90% of Navy aircraft were wired with troubled Raychem Poly-X or Stilan wires, Section 1.a,
  • doubts about the manufacturers product claims, Subsection 1.b(3) and Section 3,
  • and suggests that procurement officials may have acted improperly at Subsection 1.c.

Appendix O: Defense Industrial Supply Center Memo on Raychem 55 [MIL-W-22759/32-35, 41-43] 1982. Another memo opposing use of Raychem 55 and the selection of sole-source wires for the relevant military specifications. It documents:

  • Problems with sole-source suppliers are at Subsection 2.a.
  • Raychem's termination of Stilan wire in favor of an earlier product is noted at Subsection 2.a.
  • In Section 2.d "Totally acceptable" nonsole-source substitutes in one application for sole-source Raychem 55 were found to be available from a variety of suppliers at one-twentieth or less the cost of Raychem 55.
  • Section 2.c challenges the manufacturers performance ratings for Raychem 55.
  • Section 2.f describes the steering of a Military Specification in Air Force use towards Raychem 55 only, and that the language was removed after the lack of tests supporting this sole-source selection was challenged.


1. Nine people were killed when a cargo door ripped off a Boeing 747 in 1989. "Boeing Recommends A Change to Protect Wiring on Some Jets," Wall Street Journal, September 15, 1993.

2. Accident Investigations of Recent F-14 and AV-8B Mishaps, National Security Committee, House of Representatives, April 16, 1996.

3. Letter from Rear Admiral J.A. Cook to Representative James Greenwood, June 2, 1997.

4. Boeing Commercial Airplane Group figure cited in Final Report to President Clinton, White House Commission on Aviation Safety and Security, February 12, 1997, p.14.

5. Final Report to President Clinton, White House Commission on Aviation Safety and Security, February 12, 1997, p.14.

6. Some of Ed Block's story is written up in "Wiring System Under Scrutiny in TWA Crash," Michael Matza, Philadelphia Inquirer, September 29, 1997.

7. Safety Recommendation, A-97-56 through -77, National Transportation Safety Board, September 9, 1997.

8. Airworthiness Directive, 96-07-15, Federal Aviation Administration, May 16, 1996.

9. Verbal statement by public affairs office, National Transportation Safety Board, May 8, 1998.

10. "Flight 800: Faulty Wiring?" Earl Lane and Knut Royce, Newsday, November 22, 1996.

11. Report of Visit to National Electrical Manufacturers Association wire meeting, January 1982, Edward Block and Edward Glasgow, Defense Industrial Supply Center.

12. "First Lady's Plane Forced to Return," Associated Press, November 10, 1997.

13. "Autopilot Flaw," Bucks County Courier Times, May 18, 1992.

14. "Cohen Urges Safety Changes," Matthew Brelis and Stephen Kukjian, Boston Globe, April 11, 1998.

15. "Seeking Answers, Air Force Panel Wants New Search for Plane," Matthew Wald, New York Times, January 16, 1998.

16. "Seeking Answers, Air Force Panel Wants New Search for Plane," Matthew Wald, New York Times, January 16, 1998.

17. "NTSB Breaks Precedent, Reviews C-130 Accident Report over USAF Protest," Brendan Sobie, Inside the Air Force, July 18, 1997.

18. "NTSB Breaks Precedent, Reviews C-130 Accident Report over USAF Protest," Brendan Sobie, Inside the Air Force, July 18, 1997.

19. "Aviation Safety: Targeting and Training of FAA's Safety Inspector Workforce," General Accounting Office, GAO/T-RCED-96-26, April 30, 1996, p.1.