19970901047979A

Accident · Substantial damage

FAA accident report · Doug DC982 · Seattle, WA · September 1, 1997

Date: September 1, 1997 · 21:10 local
Place: Seattle, WA
Operating rules: Air carrier (Part 121)
Operator: ASAA
Damage: Substantial damage
Aircraft: N951AS
NTSB investigation: NTSBSEA97FA202
Reported as: Doug DC982

N951ASRegistration cancelled Apr 8, 2009 · Mcdonnell Douglas DC-9-82(MD-82)S/N 49111 · Built 1982 Airframe modelMcdonnell Douglas DC-9-82(MD-82)Engine modelPratt & Whitney JT8D-5Turbo-jet

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

(-16) On sept. 1, 1997, upon landing gear extention for landing at Seattle airport, the crew of Alaska airlines flight 255 reported an unsafe gear indication warning light. A go around was initiated and emergency checklist accomplished. After landing at approx. 60 knots the nose landing gear collapsed. An investigation revealed a failed upper lock link, part number 3914464-503. The above mentioned part is subject to airworthiness directive 97-02-10 requiring a repetitive non destructive test of 5000 cycle intervals. The upper lock link installed on N951AS had been tested 1075 cycles prior to failure.

As the FAA filed it

(-16) ON SEPT. 1, 1997, UPON LANDING GEAR EXTENTION FOR LANDING AT SEATTLE AIRPORT, THE CREW OF ALASKA AIRLINES FLIGHT 255 REPORTED AN UNSAFE GEAR INDICATION WARNING LIGHT. A GO AROUND WAS INITIATED AND EMERGENCY CHECKLIST ACCOMPLISHED. AFTER LANDING AT APPROX. 60 KNOTS THE NOSE LANDING GEAR COLLAPSED. AN INVESTIGATION REVEALED A FAILED UPPER LOCK LINK, PART NUMBER 3914464-503. THE ABOVE MENTIONED PART IS SUBJECT TO AIRWORTHINESS DIRECTIVE 97-02-10 REQUIRING A REPETITIVE NON DESTRUCTIVE TEST OF 5000 CYCLE INTERVALS. THE UPPER LOCK LINK INSTALLED ON N951AS HAD BEEN TESTED 1075 CYCLES PRIOR TO FAILURE.

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.

NTSB SEA97FA202Accident · Minor injuriesField investigationFinal reportSeattle, WAfatigue failure of the nose landing gear upper lock link, due in part to reduced strength after the manufacturing process was changed from forged to machined plate stock; and inadequate non-destructive inspection process for testing the link.Sep 2, 1997 · Substantial damage