Aviation Accident Summaries

Aviation Accident Summary LAX99IA013

HONOLULU, HI, USA

Aircraft #1

N581FE

Boeing MD-11

Analysis

The first officer was the flying pilot and detected a right wing heavy condition with roll control difficulties during liftoff. The crew dumped fuel and returned for a landing. Post landing inspection showed that three of the five spoilers on top of the right wing were fully deployed. Mechanics found a general-purpose shop rag lodged in the spoiler control pulley system, jamming it in the deployed position. The pulley area where the mechanics found the rag was an open and unprotected area in the center body landing gear wheel well. The center gear doors are normally closed on the ground; however, maintenance personnel can open the doors to work in this area. The doors open and the center landing gear retracts forward into this area during normal operation. The last maintenance completed in this area was 2 days prior to the incident when a contract fuel systems repair company opened several lines in that area to check for leaks. Mechanics could not find any rags, so a supervisor brought rags from another hangar. The supervisor was positive that he provided diaper style rags rather than shop style rags. His company only used the diaper style rag because it was more absorbent than a regular shop rag. A mechanic for the carrier said they normally used colored general-purpose shop towels. They occasionally used white terrycloth towels. The airplane completed 9 flights through various line stations prior to the mishap. On a walk around inspection, mechanics do not normally open the wheel well doors and look at the spoiler pulley system.

Factual Information

On October 21, 1998, at 1015 hours Hawaiian standard time, Federal Express flight 77, a Boeing MD-11, N581FE, returned to Honolulu, Hawaii, after it experienced roll control problems during the climb-to-cruise phase. The airplane departed from Honolulu at 0936 and returned for an uneventful landing without incident or damage. Federal Express Corporation operated the airplane under 14 CFR 121 as flight 77, a scheduled international cargo flight from Honolulu to Sydney, Australia. The airline transport pilot licensed captain, first officer, and reserve pilot were not injured. Visual meteorological conditions prevailed, and an IFR flight plan had been filed. According to the crews' written statements, the first officer was the flying pilot on the takeoff and detected a heavy right wing, with difficulty in controlling the roll attitude of the aircraft. The crew declared an emergency, dumped fuel, and returned for landing 40 minutes after departure. Upon arrival at the gate a Federal Aviation Administration inspector noted three of the five spoilers on top of the right wing were fully deployed. At the time, the engines were off, and the auxiliary power unit was operating. Examination of the airplane by maintenance personnel revealed that a general-purpose style shop rag was lodged in the pulley system that operates the Nos. 1, 4, and 5 spoilers on the right wing. The pulley area where the mechanics found the rag was an open and unprotected area in the center body landing gear wheel well. The center gear doors are normally closed on the ground; however, maintenance personnel can open the doors to work in this area. The doors open and the center body landing gear retracts forward into this area during normal operation. Review of the aircraft records disclosed that the last maintenance completed in this area was 2 days prior to the accident at Los Angeles, California. A contract fuel systems repair company opened several lines to check for leaks. This company works in the FedEx hangar and follows FedEx procedures. The supervisor stated his mechanics completed the work on a Sunday. They could not find any rags, so he brought rags from another FedEx hangar. He was positive that he provided diaper style rags rather than shop style rags. His company only used the diaper style rag because it was more absorbent than a regular shop rag. A FedEx mechanic said they normally used colored general-purpose shop towels. They occasionally used white terrycloth towels. The airplane completed 9 flights through various line stations prior to the mishap. A FedEx mechanic stated that on a walk around inspection, mechanics did not normally open the center body wheel well doors and look at the spoiler pulley system. The FedEx maintenance manual requires a daily service check. During this check, the mechanic lowers the center gear wheel well doors and inspects the inside area for condition and integrity. Records for this service check are only retained for 60 days, and no record was available to verify the last date of inspection. The manufacturer's specifications do not require the flight crew to open the center gear doors or check inside the center gear well during their preflight inspection.

Probable Cause and Findings

A jammed spoiler control pulley system caused by a shop rag left in an area of recent maintenance. Neither the maintenance organization nor the mechanic responsible could be determined.

 

Source: NTSB Aviation Accident Database

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