McDonnell Douglas MD-11F N606FE

Summary

On 5 October 1999 at about 09:40 local time, a McDonnell Douglas MD-11F registered N606FE, operated by Fedex, was involved in an accident near Newark, New Jersey, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

5 October 1999 at 09:40

Classification

Accident

Location

Newark, New Jersey, United States

Nearest airport

Newark International (EWR)

Coordinates

Not recorded

Aircraft

McDonnell Douglas MD-11F

Registration

N606FE

Category

Airplane

Engines

3

Operator

Fedex

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Indianapolis → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

NYC00LA005

Nobody was injured.

A divergent, longitudinal oscillation of undetermined origin on the center landing gear, which caused a failure of the center landing gear lower drag brace during landing roll.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

During the landing roll, the center landing gear (CLG) on the MD-11 failed in a rearward direction. The lugs on the upper attach point of the lower drag brace on the CLG failed, the landing gear retraction cylinder was pulled apart, and hydraulic fluid was lost in the #3 hydraulic system. Metallurgical examination of the failed lug found evidence of overload. The DFDR recorded a momentary peak in vertical and longitudinal accelerations, about 5.75 seconds after main landing gear touchdown, and 2.5 seconds after nose wheel touchdown. The vertical acceleration momentarily reduced, and the longitudinal acceleration momentarily increased. According to McDonnell-Douglas, the CLG was capable of entering a divergent, longitudinal oscillation, which could fail the lower drag brace lugs. There were five prior documented events that were identical. After the first three events, McDonnell-Douglas duplicated it twice again, using instrumented airplanes. They subsequently issued a service bulletin for modifications to the CLG brakes and anti-skid system. The accident airplane had these modifications. Additional testing by the operator to determine the loads on the CLG during landing did not find any high loads, and the cause of the CLG oscillation was not determined.

Quoted verbatim from the NTSB record.