Statuts: | Accident investigation report completed and information captured |
Date: | lundi 9 mai 1988 |
Heure: | 16:35 |
Type/Sous-type: | Boeing 747-136 |
Compagnie: | British Airways |
Immatriculation: | G-AWND |
Numéro de série: | 19764/107 |
Année de Fabrication: | 1971-01-20 (17 years 4 months) |
Heures de vol: | 1868 |
Moteurs: | 4 Pratt & Whitney JT9D-7A |
Equipage: | victimes: 0 / à bord: 18 |
Passagers: | victimes: 0 / à bord: 286 |
Total: | victimes: 0 / à bord: 304 |
Dégats de l'appareil: | Substantiels |
Conséquences: | Repaired |
Lieu de l'accident: | près de Chicago-O'Hare International Airport, IL (ORD) ( Etats-Unis d'Amérique)
|
Phase de vol: | En approche (APR) |
Nature: | Transport de Passagers Intern. |
Aéroport de départ: | London-Heathrow Airport (LHR/EGLL), Royaume Uni |
Aéroport de destination: | Chicago-O'Hare International Airport, IL (ORD/KORD), Etats-Unis d'Amérique |
Détails:The aircraft was on final approach to Chicago O'Hare Airport when a structural failure of the number three flap track occurred. The aircraft sustained substantial damage to the left wing, left inboard flap assembly, left inboard spoilers and spoiler support beam. The pilot experienced significant uncommanded roll and yaw, but regained control of the aircraft and executed an uneventful landing.
The investigation has revealed a history of flap track cracking problems associated with stress corrosion and design inadequacy. A design change of the member was accomplished in 1971 by the manufacturer, but flap tracks of the earlier design were allowed to remain in service on 239 aircraft. The airworthiness directives and service bulletins applicable to this particular structural member are not adequate in methodology and periodicity to ensure crack detection, and do not require inspection for the cause of the crack-corrosion pits.
Probable Cause:
PROBABLE CAUSE: "Failure of the number three flap track due to stress corrosion cracking. factors contributing to this failure are insufficient design of the member and inadequate inspection and maintenance procedures to detect cracks before they propagate to a critical length."
Sources:
» NTSB
Opérations de secours
NTSB issued 3 Safety Recommendations
Issued: 30-SEP-1988 | To: FAA | A-88-131 |
FOR BOEING 747 AIRPLANES WITH THE EARLY PRODUCTION FLAP TRACKS, REQUIRE A MAGNIFIED VISUAL OR OTHER NONDESTRUCTIVE INSPECTION, WITHIN 20 FLIGHT CYCLES OF ANY PREVIOUS INSPECTION, OF THE FORWARD BOLT HOLE BORES OF THE INBOARD FLAP TRACKS FOR CORROSION PITTING AND CRACKS USING DAMAGE TOLERANCE CRITERIA DEVISED BY BOEING, AND ESTABLISH PERIODIC INSPECTION INTERVALS FOR THE BOLT HOLE BORES CONSISTENT WITH EARLY DETECTION OF CORROSION PITTING IN THE BORES. (Closed - Acceptable Action) |
Issued: 30-SEP-1988 | To: FAA | A-88-132 |
ISSUE AN AIR CARRIER OPERATIONS BULLETIN TO ADVISE ALL OPERATORS OF BOEING 747 AIRPLANES CONFIGURED WITH THE EARLY PRODUCTION FLAP TRACKS OF THE ADVANTAGES OF OPERATING THESE AIRPLANES WITH A MAXIMUM OF 25 DEGREES-FLAP EXTENSION. (Closed - Acceptable Alternate Action) |
Issued: 30-SEP-1988 | To: FAA | A-88-133 |
REQUIRE PROMPT REPLACEMENT OF ALL EARLY PRODUCTION FLAP TRACKS ON INBOARD AND OUTBOARD FLAPS ON BOEING 747 AIRPLANES WITH NEW PRODUCTION TRACKS, AND INCLUDE THESE NEW TRACKS IN THE BOEING 747 SUPPLEMENTAL STRUCTURAL INSPECTION PROGRAM. (Closed - Acceptable Action) |
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Photos
Plan
Ce plan montre l'aéroport de départ ainsi que la supposée destination du vol. La ligne fixe reliant les deux aéroports n'est pas le plan de vol exact.
La distance entre London-Heathrow Airport et Chicago-O'Hare International Airport, IL est de 6297 km (3936 miles).
Les informations ci-dessus ne représentent pas l'opinion de la 'Flight Safety Foundation' ou de 'Aviation Safety Network' sur les causes de l'accident. Ces informations prélimimaires sont basées sur les faits tel qu'ils sont connus à ce jour.