NTSB · Safety Recommendation
Safety Recommendation A-85-129
Recommendation
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: REQUIRE THAT A REVISED FUNCTIONAL TEST BE PREPARED AND ISSUE AN AIRWORTHINESS DIRECTIVE TO IMMEDIATELY EVALUATE THE CONDITION OF ALL COMPONENTS OF THE PASSENGER OXYGEN SYSTEM ON LOCKHEED L-1011 AIRCRAFT TO ENSURE OPERATION BOTH DURING AUTOMATIC ACTIVATION AND WHEN ACTIVATED FROM THE FLIGHT ENGINEER'S STATION. (URGENT)
Safety Issue and Context
THE NTSB IS CONTINUING TO PARTICIPATE IN THE INVESTIGATION OF THE CIRCUMSTANCES OF THE IN-FLIGHT FIRE WHICH WAS DETECTED ONBOARD A ROYAL JORDANIAN AIRLINES LOCKHEED L-1011 AIRPLANE WHILE THE AIRPLANE WAS DESCENDING TO LAND AT SINGAPORE ON OCTOBER 18, 1985. THE EXAMINATION OF THE AIRPLANE WAS CONDUCTED IN SINGAPORE BY AN INVESTIGATION TEAM THAT INCLUDED REPRESENTATIVES OF THE SAFETY BOARD. THE PRELIMINARY INVESTIGATION DISCLOSED THAT THE FIRE ORIGINATED IN THE LEFT AFT UNDERFLOOR AREA OF THE AIRPLANE'S FUSELAGE, AFT OF THE C-3 CARGO COMPARTMENT AND FORWARD OF THE REAR PRESSURE BULKHEAD.
THE SAFETY BOARD'S CONCERN THAT THE FIRE IGNITED AS A RESULT OF ELECTRICAL ARCING BETWEEN A FRAYED GENERATOR FEEDER CABLE AND A THIN WALL TITANIUM DUCT CONTAINING HIGH-PRESSURE BLEED AIR AND THE FIRE'S SUBSEQUENT PROPAGATION TO OTHER FUEL SOURCES WAS DESCRIBED IN A LETTER TO THE FEDERAL AVIATION ADMINISTRATION (FAA) DATED OCTOBER 25, 1985. THE SAFETY RECOMMENDATIONS CONTAINED IN THAT LETTER, A-85-91 AND -92, ADDRESS ACTIONS NEEDED TO PREVENT FUTURE OCCURRENCES OF A SIMILAR NATURE.
THE INVESTIGATION OF THE ACCIDENT DISCLOSED OTHER DISCREPANCIES IN THE L-1011 AIRPLANE WHICH WERE NOT CAUSAL TO THE EMERGENCY BUT WHICH COULD ADVERSELY AFFECT THE SAFETY OF PASSENGERS DURING AN EMERGENCY SITUATION.
Response History
May 13, 1986 · NTSB Correspondence · FAA
The Safety Board is pleased to note that the FAA has amended 14 CFR 39, by adopting a new Airworthiness Directive (AD), effective January 21, 1986. This AD requires a resistance test and replacement, if necessary, of the oxygen initiator sequence timer switch in accordance with Lockheed Service Bulletin 093-35-041 on all L-1011 airplanes within 30 days after the AD's effective date. The provisions of this AD satisfy Safety Recommendation A-85-129 which is classified "Closed--Acceptable Action."
February 20, 1986 · Recipient Response · FAA
THE FAA CONCURS WITH THE BOARD'S RECOMMENDATION AND HAS ISSUED AN IMMEDIATELY ADOPTED AD.-----THIS AD REQUIRES A RESISTANCE TEST AND REPLACEMENT, IF NECESSARY, OF THE OXYGEN INITIATOR SEQUENCE TIMER SWITCH IN ACCORDANCE WITH LOCKHEED SERVICE BULLETIN 093-35-041 ON ALL L-1011 AIRPLANES WITHIN 30 DAYS AFTER THE AD'S EFFECTIVE DATE. THE AD WILL ENSURE THAT SHORTED DORMANT TRANSIENT SUPPRESSOR CAPACITATORS DO NOT EXIST IN ANY OF THE SEQUENCERS.