Vliegtuigongeval op 01 MAR 1994 met Boeing 747-251B N637US - Tokyo-Narita Airport (NRT)
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Status:Accident investigation report completed and information captured
Datum:dinsdag 1 maart 1994
Type:Silhouette image of generic B742 model; specific model in this crash may look slightly different
Boeing 747-251B
Luchtvaartmaatschappij:Northwest Airlines
Registratie: N637US
Constructienummer: 23548/644
Bouwjaar: 1986-05-10 (7 years 10 months)
Aantal vlieguren:31798
Motoren: 4 Pratt & Whitney JT9D-7R4G2
Bemanning:slachtoffers: 0 / inzittenden: 18
Passagiers:slachtoffers: 0 / inzittenden: 227
Totaal:slachtoffers: 0 / inzittenden: 245
Schade: Groot
Gevolgen: Repaired
Plaats:Tokyo-Narita Airport (NRT) (   Japan)
Fase: Landing (LDG)
Soort vlucht:Internationale lijnvlucht
Vliegveld van vertrek:Hong Kong-Kai Tak International Airport (HKG/VHHH), Hong Kong
Vliegveld van aankomst:Tokyo-Narita Airport (NRT/RJAA), Japan
Vluchtnummer: 18
Northwest Airlines Flight 18 had departed from Hong Kong for a flight to New York-JFK with an intermediate stop at Tokyo-Narita, Japan. The flight, touchdown, and initial landing rollout at Narita, were routine. Engine thrust reversing was normal on all four engines until the flight crew moved the engine power levers out of reverse thrust at about 90 knots. During the rollout, the No. 1 engine and pylon rotated downward about the midspar pylon-to-wing fittings into a position in which the lower forward part of the engine nose cowl contacted the runway. The airplane was subsequently stopped on a taxiway, with the front of the No. 1 engine still contacting the ground. The lower forward engine nose cowl had been ground away as it slid along the runway. A fire near the No. 1 engine was rapidly extinguished by local fire fighters, and all passengers remained aboard. They were subsequently deplaned via portable boarding stairs about 30 minutes after the airplane was brought to a stop. There were no injuries.
Maintenance and inspection personnel who worked on the airplane were not adequately trained and qualified to perform the required maintenance and inspection functions. In addition, the work environment for the heavy maintenance of the airplane was inadequate and contributed to an effort producing situation for the workers.

Probable Cause:

PROBABLE CAUSE: "When C check of the aircraft was conducted, the retainer for the diagonal brace aft fuse pin of No.1 nacelle strut was removed and the aircraft was returned to service without reinstalling the retainer. In the course of the flights after this, the fuse pin moved, disconnecting the diagonal brace at the aft joint.
It is estimated that when the thrust reverser was deployed during the landing roll under such circumstances, the forward fuse pin of the upper link was fractured due to a load in excess of the design rupture strength, dangling the forward portion of No.1 engine and a fire on leaked oil and fuel broke out in the aft portion of the nacelle strut."

Accident investigation:

Investigating agency: ARAIC Japan
Status: Investigation completed
Duration: 2 years and 9 months
Download report: Final report

» NTSB/SIR-94/02

The NTSB made several recommendations to the Federal Aviation Administration concerning human engineering principles in maintenance operations, and the critical assessment of maintenance work environments. Recommendations were made to Northwest Airlines concerning the same subjects.

NTSB issued 9 Safety Recommendations

Show all...


photo of Boeing-747-251B-N637US
accident date: 01-03-1994
type: Boeing 747-251B
registration: N637US
photo of Boeing-747-251B-N637US
accident date: 01-03-1994
type: Boeing 747-251B
registration: N637US
photo of Boeing-747-251B-N637US
accident date: 01-03-1994
type: Boeing 747-251B
registration: N637US
photo of Boeing-747-251B-N637US

Deze kaart geeft het vliegveld van vetrek weer en de geplande bestemming van de vlucht. De lijn tussen de vliegvelden geeft niet de exacte vliegroute weer.
De afstand tussen Hong Kong-Kai Tak International Airport en Tokyo-Narita Airport bedraagt 2920 km (1825 miles).
Accident location: Exact; deduced from official accident report.

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.
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