link
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6. -----------

Sept 29, 1995. A-94-133 . (Also See A-94-134, A-94-135, A-94-136) 

On Oct. 16, 1993 heavy smoke came out of the overhead of a Swissair MD-81 with substantial damage and overheated electrical components. The NTSB recommendation was to limit the emergency power switch to 10,000 cycles. (A-94-136 called for a relay type circuit design to keep such high power out of the cockpit, A-94-135 asked for reduced usage/cycles and A-94-136 requested a determination be made as to the source of the high energy current that damaged the switch). AD-95-11-12 affecting DC-9 series MD-80 and 88s required the repetitive replacement of the switch every 3 years. The source of the overheating was laid to the switch (in A-94-136).

Data_Source: NTSB Recommendations to FAA and FAA Responses

See; http://nasdac.faa.gov/asp/asy_searchus.asp  ‘Search’ A-94-133, or see -

link


7. ------- 

January 11, 1999. A-99-3. Swissair Flight 111. In-flight fire. Some wires exhibiting arcing damage were unique to the entertainment system but others were original equipment. In Dec. 1998, the TSB issued a advisory and that the potential safety ramifications appear limited to the MD-11 fleet. The NTSB recommends an expedited inspection of all MD-11 wiring for discrepancies in wiring, around the cockpit overhead and the avionics circuit breaker panel.

FAA action, Open-Pending. Source; http://www.ntsb.gov/recs/letters/1999/A99_3.pdf

8. -------- 

December 15, 1999. A-99-104 to 106. A Delta MD-11 forward cargo compartment erupted in a fire at the gate as a result of overheated connector pins in a cargo control unit. Two additional MD-11 events were claimed as the fires also consumed the adjacent Mylar insulation blankets. A recommendation for an AD for a additional thermal barrier and protection was requested. FAA action, Open-Pending.

Source; http://www.ntsb.gov/recs/letters/1999/A99_104_106.pdf

9. --------

September 19, 2000. A-00-105 to 108. TWA 800 in-flight fuel tank explosion. Recommendations to the FAA include; Review the design specifications for wire. Address all issues in identified in the Aging Transport Non-Structual Systems Plan including improved documentation of potentially unsafe wiring conditions and incorporate new technology arc-fault circuit breakers and automated test equiptment. FAA action, Open-pending.

Source; http://www.ntsb.gov/recs/letters/2000/A00_105_108.pdf

10. ---------

February 6, 2001, A-01-03 to –05. A Delta MD-88 forward cargo caught fire due to a arcing short (115 volt lead wire short to case/ground) at the right static-port heater. Mylar insulation propagated the fire. A Delta fleet survey of 136 aircraft (MD-88/90s) found 11 % with similar failure levels. The NTSB recommends an AD to inspect all MD-80, MD-90 and DC-9s for burn damage, issue a design review and issue a AD for MD- and MD-90 Mylar replacement near the heaters (4) at the nearest maintenance opportunity. FAA action, Open-pending

Source; http://www.ntsb.gov/recs/letters/2001/a01%5F03%5F05.pdf

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Limitations; This search only includes selected reports because the search engine was not consistent.

For example, Item 4, (A-91-71), could not be found in the “L-1011” files, but only knowledge of the exact file number permitted retrieval. Similarly, a review of http://www.faa.gov/avr/afs/hbaw/hbawl.htm  could not find this Handbook Bulletin some 10 years later from the claim it was issued in 1991. And neither does the NTSB have its promised copy. In a January 13, 1999 NTSB response, Melba D. Moye, FOIA Officer, said; “Lastly, the Board does not have a copy of the “Handbook Bulletin 91-15.” ).

Of 350 Records; The first five of these Recommendations, related to wiring, were retrieved by at the “NTSB Recommendations To the FAA With FAA Responses” and search engine http://nasdac.faa.gov/asp/asy_searchus.asp  The remaining five were retrieved directly from the NTSB web site with the URLs indicated. 

Over 350 records were reviewed with the following number of records noted; DC-9 and –80s - 208 records, L-1011- 109 records, NTSB website – 76 records, MD-88s – 67 records, MD-87s – 3 records and MD-90s – 2 records.



Questions or comments may be directed to IASA’s Dataman at john.king19@comcast.net


We (readers) should understand that;


The NTSB files are incomplete because their file "A-91-71 & 72 are missing. (dirty wire bundles),


The NTSB participated in that extensive Danish investigation but offered no recommendations…...and


The NTSB file on that Philippine 737 accident shows the FAA turned down both recommendations then to check the wiring ..... wouldn't it be interesting if the NTSB makes this call again with the Thai Airlines 737 that blew on the tarmac at Bangkok in March 01 ?


'notations'


"Of these, only ten were found with clear relevance to wiring including one found only because there was a specific file-number to hand. This one (item 4, A-91-71) involved the 1991 NTSB/FAA action to clean lint and debris off wire bundles as a result of a L-1011 wire bundle fire in 1991. No real surprise here as this has come back to bite them many times now and as the ATSRAC findings have now noted significant lint and debris buildups and potentials for the same type fires identified here in 1991." 



"No surprise again as this would be that SAS MD-87 incident of 1983 and to which the Danish AAIB Report of 1996 claimed that both the "NTSB and the FAA participated" in their investigation. We may also note that the 1994 FAA Tech Center four page letter and report of fire tests appendixed into this Danish Report cannot be found at the Tech Center records said a recent FAA FOIA response."



"This is Item 5 where a 1990 737-300 leased to Philippine Airlines exploded on the ramp. The NTSB recommended then for increased inspections of the wiring where this was denied by the FAA. We watch with interest as the initial reports from the NTSB's investigation of Thai Airlines now point in the same direction of the center wing fuel tank. "