NYC97LA009

NTSB accident investigation · McDonnell Douglas MD-80 · Jamaica, NY · October 29, 1996

Accident · Serious injuriesLimited investigationFinal report
Date
October 28, 1996, 22:31 local (Oct 29, 1996, 03:31 UTC)
Place
Jamaica, NY
Injuries
1 serious, 2 minor, 90 uninjured
Damage
Minor damage
Phase of flight
Landing
Aircraft
N244AAMcDonnell Douglas MD-80
Weather
Visual (VMC) · Night/dark
Status
Completed · report September 12, 2000
Report
Approved by Office Director
FAA report
19961028045729A
Case key
39298

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

Failure of the nose landing gear upper lock link.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Wheels up landingLanding
Landing gear,nose gear assembly - failureCause

Analysis

The flight was inbound to land, when the flight crew observed an unsafe nose gear indication. The crew was unable to confirm that the gear was down, and diverted to Runway 31R at JFK. The airplane landed on the runway, with the nose gear retracted, and an emergency evacuation was performed. Examination of the wreckage revealed the nose landing gear upper lock link was fractured into two pieces. The linkage jammed against the shock strut structure, preventing extension of the strut. According to the airplane manufacturer, the nose landing gear upper lock link failed due to fatigue. It was made from aluminum plating. Originally, all the links were made from forged aluminum. Then, the company used plated aluminum because it weighed less. Although both types of lock links were of the same strength, the aluminum plating fatigued sooner than the forged links. After the accident, the company replaced all aluminum plated upper lock links with forged ones.

Factual narrative

On October 28, 1996, about 2231 Eastern Standard Time, American Airlines flight 346, a McDonnell Douglas MD-80, N244AA, sustained minor damage while landing with the nose gear retracted at John F. Kennedy International Airport (JFK), Jamaica, New York. Visual meteorological conditions prevailed for the flight that departed Chicago O'Hare International Airport, Chicago, Illinois; destined for LaGuardia Airport (LGA), Flushing, New York. There were 93 occupants on board; 1 passenger received serious injuries, and 2 passengers received minor injuries. An instrument flight rules flight plan was filed for the air carrier flight conducted under 14 CFR Part 121.

The flight was inbound to Runway 31 at LGA when the flight crew observed an unsafe nose gear indication. A low approach was made at LGA for ground personnel to visually determine the nose gear position. They could not confirm the nose gear was down and locked. The flight crew decided to divert to JFK, where a landing was made on Runway 31R, and a subsequent emergency evacuation was performed.

Examination of the wreckage revealed that the nose landing gear upper lock link (P/N 3914464-503) was fractured into two pieces. The linkage jammed against the shock strut structure, preventing extension of the strut.

According to an analysis by McDonnell Douglas, the upper lock link failed because it was made from a substitute material (aluminum plate) in place of aluminum forging. The aluminum plate had a lower allowable fatigue in comparison to aluminum forging.

A representative from McDonnell Douglas stated that the original aluminum forging was replaced by aluminum plating because of lighter weight. After the accident, the company replaced all aluminum plated links with aluminum forging.

American Airlines conducted a fleet wide inspection, and found one other cracked lock link.

Aircraft

Registration
N244AA
Reported as
McDonnell Douglas MD-80
Category
Airplane
Serial number
49256
Engine
P&W JT8D, 20,000 lbs thrust, turbo fan
Damage
Minor damage
Flight
Part 121
Operator
American Airlines, Inc
Registered owner
Fleet National Bank
Airworthiness certificate
Standard, Transport
Departed
ORD · Chicago, IL
Destination
LGA · Flushing, NY
Flight plan
IFR
Airport
JFK · John F. Kennedy Intl Apt, runway 31R, 10,000 × 150 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
46
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
4,895 total · 3,816 in this make and model · 2,502 as pilot in command · 132 in the last 90 days · 54 in the last 30 days

Weather

Conditions
Visual (VMC) · Night/dark
Wind
320° at 19 knots, gusting 30
Visibility
10 statute miles
Lowest ceiling
None
Temperature
50 °F
Altimeter
29.00 inHg
Observed at
JFK

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N244AA · 1

Matched to the same aircraft by N-number and date.