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| Subject: Edward Block on aircraft wiring |
Date: Wed, 30 Dec 1998 11:16:08 -0500
From: Ader <ader@compuserve.com>
To: timothyclark <timothyclark@compuserve.com>, jay miller <JNiessen@aol.com>,
mgoldfein <mgoldfein@belo-dc.com>, david evans <devans@phillips.com>,
edward Block <EdwBlock@aol.com>, clittle <clittle@cari.net>, john sampson
<sampson@iinet.net.au>,
john king <jking1@mediaone.net>, tim dobbyn <tim.dobbyn@reuters.com>,
omega <omega@omegainc.com>, barry smith <barry@corazon.com>,
wireman <wireman@hfx.andara.com>, lyn romano <rosebush2@hotmail.com>,
rwroland <rwroland@aol.com>, jim bennett <sai@cybercenter.cl>,
| Written by Ed Block I quote Block again: “The most important point in wire problems are the different types on each plane. It certainly does matter when you have to decide (as a pilot) whether to reset circuit-breakers. It is the Achille’s heel of the industry. This aspect must be included, or the whole matter will be relegated to best available status. Kapton is being used by NASA on the Space Station. Can you imagine the credential witnesses that could be called? The issue is wire, not Kapton, so we should not play into their hands. The blood on the hands will matter only when dealt with as a whole. There is a much more sinister issue here than polyimides, patents, NATO market place domination, etc. He wrote a letter to AlgoPlus Consulting Ltd. in Halifax, of which the contents I quote in full here: “I’m sorry I couldn’t get back to you sooner, but things are definitely moving fast. I wanted to first congratulate you on being able to appreciate the need for statistical analysis in making any meaningful decision (although obviously limited by the quality of that data). The problem then is how to fine-tune the data. In 1982 I conducted a survey of the major aircraft manufacturers who were members of the SAE’s High Temperature Insulated Wire Committee (see enclosure #1). This poll provides keen insights into the evolution of the design criteria used in the selection of various wiring insulation types for the initial construction of these aircraft. I have since acquired additional documentation (see enclosure #2) that amplifies the specific changes that were made, and obviously only when an insulation material was shown to fail. The move from Polyvinyl Chloride (PVC) used since jet-powered aircraft, came about due to the insulation material failing the FAA’s only prehistoric flammability test (60 degree and no smoke test). It was followed with the introduction of Poly-X wire in 1969 (early DC-10s and 747s). Its demise came in 1975 when the premature aging problem was discovered/admitted. This inherent quality of the insulation material resulted in radial-cracking of the insulation, down to the conductor. Next came Stilan, this insulation material had a stress-crazing problem (internal shattering), in addition to its susceptibility to de-icing fluid and hydraulic fluid, causing it to be replaced in 1978. Then came XL-EFTE (MII-W-22759/34,55 or irradiated Tefzel) and even though it has a 97% smoke optical density rating (see enclosure #3) it is still being used today by Boeing in its 747, 767, and 777 lines. This is particularly alarming when you consider Grumman Corp. had banned it in 1982 from manned-aerospace flights, due to the insulation’s toxicity, and NASA’s subsequent ban in 1983, when they (NASA) determined this material could explode in an oxygen-enriched area (e.g. cargo-bay). The subsequent decisions on the ‘by default’ use of Kapton go back to 1972, when arc-tracking was first re-created by Lockeed Corp. in a laboratory. In 1977, TWA had asked Boeing not to put this insulation in any more of their aircraft, and by 1984, the FAA’s own internal documentation showed the problems being experienced with this material. In 1987, the military finally banned Kapton from further use, and in 1988 the FAA conducted their own experiments on arc-tracking after receiving a letter from the Energy and Commerce Committee, based on my (Block’s) prior briefing to them. The majority of aircraft built today should hopefully now have TKT, a composite construction, that should limit problems in the future, however political issues have remained in the equation to this day. In 1992, I briefed the GAO’s Transportation Dept. on this problem (see enclosure #4). They sent letters to the NTSB/FAA asking them if there was indeed a problem with the various wire insulations used in commercial aircraft. Their respective replies clearly indicated that the problem with wire insulations was that no one was in a position to even know if there was one. They relied totally on the manufacturers for this expertise. In 1994 I briefed the FAA in Seattle and Atlantic City, NJ, on the problems associated with the various types of degrading wire, that the Military had experienced. Their answer was indicative of the aforementioned real problem (see enclosure #5), - that no one had a clue to the seriousness of the matter. In 1995, I had the NTSB/FAA form a Joint Task Force to address this matter more fully. The results of them once again asking only the manufacturers for an assessment of any problems with aircraft wiring was predictable, i.e. there was no problem. The NTSB replied in February, 1996, the FAA (after ValuJet 592 and TWA 800), in November of 1996. I then turned to the White House Commission and my efforts in supplying them with documents and video-cassettes finally paid off (enclosure #6). They acknowledged that non-structural components e.g. wire and cable had been overlooked in regard to safety concerns in February 1997. On April 10, 1997 I briefed Congress, the FAA, the FBI, the DOTIG, GAO, the Navy Dept., etc. on the problems with wiring in aircraft. The result: there was no problem showing up in the database. I have given this brief history to underscore the need to analyze/isolate wire failures by type. Enclosure #7 is therefore the reason I am writing to you. The last sentence on page 1 is the root of this matter, that being that the FAA still maintains that ‘wire is wire’. Even though the FAA contradicts themselves on this issue at every turn (see enclosure # 8), they still want to group wires into one ‘nondescript’ bundle, that ultimately gets replaced in the course of the aircraft’s life. Similarly it is supposed, that as long as they are ‘maintained’ in the interim, they will last the ‘life’ of an aircraft. The information presented herein proves conclusively that wire is not wire. The statement cited in the 3rd paragraph of the NTSB’s response (see enclosure #9) concurs with this. The statement in the subsequent NTSB response (enclosure #10) further proves the distinctions made in wire types. This brings us to the current need, as evidenced by the FAA’s Non-Structural Systems Plan announced October 1, 1998. In the Plan’s Findings (see enclosure #11) they clearly state “there is currently no systematic process to identify and address potentially catastrophic failures caused by electrical faults of wiring systems, aside from accident investigation associated activities”. This declaration is more telling than it may appear, beyond the fact that the Plan makes no distinctions regarding the various wire types nor their related failure modes. (Enclosure #12) is a clear case in point, in that this letter from the NTSB (accident investigation phase that the FAA’s Plan is relying on), acknowledges that even they cannot correctly distinguish between various wire types (Sorry, it is not Kapton, it is XL-EFTE). Therefore, since the FAA admits to allowing the manufacturers to choose the wire types for their aircraft, and they do not then call for any comprehensive flammability and smoke tests (like they do on seat-covers) to prove they are safe, and since the FAA says there is currently no systematic process to address potential catastrophic wire failures in advance, (clearly the NTSB is obviously not up to the task either, other than relying on those same manufacturers the FAA originally relied on, via the ‘party system’), and in that the FAA is not alerting the pilots of Kapton wired aircraft to not reset circuit-breakers since "wire is wire", something needs to be done. I would like to see the development of a model by model SDR base, that is linked specifically by wire type used. I do not know what this would take, but I would like your opinion/input. This would provide a more fine-tuned look at the problems related to the wiring we are facing, and dispel the notion that wire is replaced, maintained, or that wire is wire. Also, when the wire manufacturer announced Poly-X wire they said perhaps it could last 60,000 hours. TWA 800, wired with Poly-X had 93,303. That is the next hurdle, establishing a realistic life-expectancy for wire. Please let me know of any questions or comments. My phone number is (215) 750-7570. Sincerely, Edward Block |
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