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Accident
Last updated: 19 October 2017
Statuts:Enquête Officielle
Date:lundi 12 mai 1997
Heure:15:29
Type/Sous-type:Silhouette image of generic A306 model; specific model in this crash may look slightly different
Airbus A300B4-605R
Compagnie:American Airlines
Immatriculation: N90070
Numéro de série: 513
Année de Fabrication: 1989-03-01 (8 years 2 months)
Moteurs: 2 General Electric CF6-80C2A5
Equipage:victimes: 0 / à bord: 8
Passagers:victimes: 0 / à bord: 155
Total:victimes: 0 / à bord: 163
Dégats de l'appareil: Mineurs
Conséquences: Repaired
Lieu de l'accident:près de West Palm Beach, FL (   Etats-Unis d'Amérique)
Phase de vol: En approche (APR)
Nature:Transport de Passagers Nat.
Aéroport de départ:Boston-Logan International Airport, MA (BOS/KBOS), Etats-Unis d'Amérique
Aéroport de destination:Miami International Airport, FL (MIA/KMIA), Etats-Unis d'Amérique
Numéro de vol:AA903
Détails:
The flight was assigned an airspeed of 230 knots and cleared to descend from FL240 to 16,000 feet in preparation for landing at Miami. The FDR indicated that while the autopilot was engaged in the descent, the power levers moved from the mechanical autothrottle limit of 44 degrees to the manual limit of 37 degrees. As the aircraft leveled at 16,000 feet the airspeed decreased. The F/O began a right turn to enter a holding pattern and added some power, which stabilized the airspeed at 178 knots. However, the right bank and the resultant angle of attack (AOA) continued to increase, despite left aileron input by the autopilot. As the autopilot reached the maximum input of 20 degrees, bank angle increased past 50 degrees, and the AOA increased rapidly from 7 degrees to 12 degrees. At this point the stick shaker activated, the autopilot independently disconnected, the power was increased, and full left rudder was used to arrest the roll. The bank angle reached 56 degrees, and the AOA reached 13.7 degrees at 177 knots. The aircraft then pitched down, and entered a series of pitch, yaw, and roll maneuvers as the flight controls went through a period of oscillations for about 34 seconds. The maneuvers finally dampened and the crew recovered at approximately 13,000 feet. One passenger was seriously injured and one flight attendant received minor injuries during the upset.
An analysis showed that the forces during the upset not only had gone above the design limit of the vertical stabilizer, they also apparently had reached the ultimate limit. In June 1997, Airbus requested that American Airlines perform another inspection of the jet to ensure it was not damaged. American inspectors, following Airbus' instructions, examined the tail fin. But they did not use methods that would have allowed them to see inside the tail fin. They saw no damage from their visual inspection, and the jet continued to fly until an ultrasound inspection of the horizontal stabilizer was done in March 2002. The inspection found two crescent-shaped cracks at one of the points where the tail fin attaches to the fuselage. The fin was replaced.

Probable Cause:

PROBABLE CAUSE:"The flightcrew's failure to maintain adequate airspeed during leveloff which led to an inadvertent stall, and their subsequent failure to use proper stall recovery techniques. A factor contributing to the accident was the flightcrew's failure to properly use the autothrottle."

Accident investigation:
cover
Investigating agency: NTSB
Status: Investigation completed
Duration: 2 years and 9 months
Accident number: DCA97MA049
Download report: Summary report

Sources:
» NTSB
» USA Today 27-5-2003


Opérations de secours

NTSB issued 5 Safety Recommendations

Show all AD's and Safety Recommendations

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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 Boston-Logan International Airport, MA et Miami International Airport, FL est de 2014 km (1259 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.
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