Narrative:The rear main spar of the right wing failed as Delta flight 194 touched down on runway 29 at Newark Airport. The pilots stated that there was moderate turbulence on final approach and initial touchdown was on the right main gear first. The touchdown was firm but not hard which was confirmed from the 1.4g recorded on the DFDR. The 1.4g force is well within the landing gear certification limits.
The spar web failure was caused by a fatigue crack that originated at a 'hi-loc' fastener hole located at the lower inboard corner of a doubler that surrounds the fuel filler valve which is mounted vertically on the spar web. The fatigue zone in the spar web had progressed about 6 3/4 inches before the web failed as the airplane touched down. The fracture in the spar web extended diagonally downward and outboard at 45 degrees from inboard wing station 241.0 to inboard station 293.5. The flight crew did not report any airplane malfunction during the flight.
Probable Cause:
PROBABLE CAUSE:
wing..fatigue
acft/equip,inadequate design..manufacturer
Classification:
Wing failure
Runway mishap
Sources:
» NTSB
Follow-up / safety actions
NTSB issued 3 Safety Recommendations
Issued: 19-NOV-1986 | To: FAA | A-86-128 |
REQUIRE AN IMMEDIATE INSPECTION USING METHODS ADEQUATE TO DETECT FATIGUE CRACKING OF THE WING REAR SPAR WITH EMPHASIS ON THE SPAR WEB AT THE LOWER INBOARD FASTENER HOLE FOR THE FORWARD SIDE DOUBLER REINFORCING THE FUEL FILLER VALVE HOLE OF ALL LOCKHEED L-1011 AIRPLANES HAVING MORE THAN A CONSERVATIVELY ESTABLISHED THRESHOLD OF BOTH FLIGHT HOURS AND FLIGHT CYCLES; THE THRESHOLD SHOULD BE PREDICATED UPON THE TIME AND CYCLES ON THE ACCIDENT PLANE. (Closed - Acceptable Action) |
Issued: 19-NOV-1986 | To: FAA | A-86-129 |
REVISE THE APPROVED INSPECTION PROGRAMS FOR LOCKHEED L-1011 AIRPLANES AS NECESSARY TO ESTABLISH INSPECTION THRESHOLDS, INTERVALS, AND METHODS WHICH ARE ADEQUATE TO DETECT FATIGUE CRACKING OF PRIMARY WING STRUCTURE. (Closed - Acceptable Action) |
Issued: 19-NOV-1986 | To: FAA | A-86-130 |
NOTIFY FOREIGN CERTIFICATION AUTHORITIES ABOUT THE CIRCUMSTANCES OF THIS ACCIDENT AND THE NEED FOR REMEDIAL ACTIONS. (Closed - Acceptable Action) |
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Photos
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Atlanta-William B. Hartsfield International Airport, GA to Newark International Airport, NJ as the crow flies is 1191 km (744 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.