| Statuts: | Enquête Officielle |
| Date: | 25 MAI 1979 |
| Heure: | 15:04 |
| Type/Sous-type: | McDonnell Douglas DC-10-10 |
| Compagnie: | American Airlines |
| Immatriculation: | N110AA |
| Numéro de série: | 46510/22 |
| Année de Fabrication: | 1972 |
| Heures de vol: | 19871 |
| Moteurs: | 3 General Electric CF6-6D |
| Equipage: | victimes: 13 / à bord: 13 |
| Passagers: | victimes: 258 / à bord: 258 |
| Total: | victimes: 271 / à bord: 271 |
| Victimes au sol: | victimes: 2 |
| Dégats de l'appareil: | Détruit |
| Conséquences: | Written off (damaged beyond repair) |
| Lieu de l'accident: | Chicago-O'Hare International Airport, IL (ORD) (Etats-Unis d'Amérique)
 |
| Phase de vol: | Au décollage (TOF) |
| Nature: | Transport de Passagers Nat. |
| Aéroport de départ: | Chicago-O'Hare International Airport, IL (ORD/KORD), Etats-Unis d'Amérique |
| Aéroport de destination: | Los Angeles International Airport, CA (LAX/KLAX), Etats-Unis d'Amérique |
| Numéro de vol: | 191 |
Détails:Flight 191 left the gate at Chicago-O'Hare at 14:59 and taxied to runway 32R. At 15:02 the flight was cleared for takeoff. The takeoff roll was normal until just before rotation at which time sections of the No. 1 engine pylon structure came off the aircraft. During rotation the entire no. 1 engine and pylon separated from the aircraft, went over the top of the wing, and fell to the runway. Flight 191 lifted off about 6,000 feet down the runway, climbed out in a wings level attitude, and reached an altitude of about 300 feet agl with its wings still level. Shortly thereafter, the aircraft began to turn and roll to the left, the nose pitched down, and the aircraft began to descend. As it descended, it continued to roll left until the wings were past the vertical position. The DC-10 crashed in an open field and trailer park about 4,680 feet northwest of the departure end of runway 32R. The aircraft was demolished during the impact, explosion, and ground fire. Two persons on the ground were killed.
PROBABLE CAUSE: "The asymmetrical stall and the ensuing roll of the aircraft because of the uncommanded retraction of the left wing outboard leading edge slats and the loss of stall warning and slat disagreement indication systems resulting from maintenance-induced damage leading to the separation of the no.1 engine and pylon assembly procedures which led to failure of the pylon structure.
Contributing to the cause of the accident were the vulnerability of the design of the pylon attach points to maintenance damage; the vulnerability of the design of the leading edge slat system to the damage which produced asymmetry; deficiencies in FAA surveillance and reporting systems which failed to detect and prevent the use of improper maintenance procedures; deficiencies in the practices and communications among the operators, the manufacturer, and the FAA which failed to determine and disseminate the particulars regarding previous maintenance damage incidents; and the intolerance of prescribed operational procedures to this unique emergency."
Sources:
» NTSB Safety Recommendations A-79-98/105
» NTSB-AAR-79-17
Official accident investigation report
Sample newspaper article from Newspaperarchive.com
Opérations de secours
On June 6, 1979, after a series of postaccident inspections disclosed damaged aft bulkheads in the wing to engine pylons, the Administrator of the FAA
issued an Emergency Order of Suspension. The Order suspended the DC-10 series aircraft type certificate "until such time as it can be ascertained that the DC-10 aircraft meets the certification criteria of Part 25 of the FAR and is eligible for a Type Certificate."
On June 26, 1979, the FAA issued Special Federal Aviation Regulation 40 which prohibited the "operation of any Model DC-10 aircraft within the airspace of the United States."
On July 13, 1979, after a series of formal investigations, the Administrator found that the DC-10 met the requirements for issuance of a type certificate. Accordingly, the Emergency Order of Suspension was terminated.
In November 1979 the FAA fined American Airlines $500,000 for using a faulty maintenance procedure on its DC-10 aircraft by using forklift trucks to mate the complete engine/pylon assembly with wing attachment points. Continental Airlines was fined $100,000 on a similar charge.
NTSB issued 12 Safety Recommendations
| Issued: 27-MAY-1979 | To: | A-79-041 |
| ISSUE IMMEDIATELY AN EMERGENCY AIRWORTHINESS DIRECTIVE TO INSPECT ALL PYLON ATTACH POINTS ON ALL DC-10 AIRCRAFT BY APPROVED INSPECTION METHODS. (Closed - Acceptable Action) |
| Issued: 04-JUN-1979 | To: | A-79-045 |
| ISSUE A TELEGRAPHIC AIRWORTHINESS DIRECTIVE TO REQUIRE AN IMMEDIATE INSPECTION OF ALL DC-10 AIRCRAFT IN WHICH AN ENGINE PYLON ASSEMBLY HAS BEEN REMOVED AND REINSTALLED FOR DAMAGE TO THE WING-MOUNTED PYLON AFT BULKHEAD, INCLUDING ITS FORWARD FLANGE AND THE ATTACHING SPAR WEB AND FASTERNERS. REQUIRE REMOVAL OF ANY SEALANT WHICH MAY HIDE A CRACK IN THE FLANGE AREA AND EMPLOY EDDY-CURRENT OR OTHER APPROVED TECHNIQUES TO ENSURE DETECTION OF SUCH DAMAGE. (Closed - Acceptable Action) |
| Issued: 04-JUN-1979 | To: | A-79-046 |
| ISSUE A MAINTENANCE ALERT BULLETIN DIRECTING FAA MAINTENANCE INSPECTORS TO CONTACT THEIR ASSIGNED CARRIERS AND ADVISE THEM TO IMMEDIATELY DISCONTINUE THE PRATICE OF LOWERING AND RAISING THE PYLON WITH THE ENGINE STILL ATTACHED. CARRIERS SHOULD ADHERE TO THE PROCEDURE RECOMMENDED BY THE DOUGLAS AIRCRAFT COMPANY SERVICE BULLETIN WHICH INCLUDE REMOVING THE ENGINE FROM THE PYLON BEFORE REMOVING THE PYLON FROM THE WING. (Closed - Acceptable Action) |
| Issued: 22-JUN-1979 | To: | A-79-052 |
| ISSUE A MAINTENANCE ALERT BULLETIN TO U.S. CERTIFICATED AIR CARRIERS, AND NOTIFY STATES THAT HAVE REGULATORY RESPONSIBILITIES OVER FOREIGN AIR CARRIERS OPERATING DC-10 AIRCRAFT, TO REQUIRE APPROPRIATE STRUCTURAL INSPECTIONS OF THE ENGINE PYLONS FOLLOWING ENGINE FAILURES INVOLVING SIGNIFICANT IMBALANCE CONDITIONS OR SEVERE SIDE LOADS. (Closed - Acceptable Alternate Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-098 |
| INCORPORATE IN TYPE CERTIFICATION PROCEDURES FULL CONSIDERATION OF (Closed - Acceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-099 |
| INSURE THAT THE DESIGN OF TRANSPORT CATEGORY AIRCRAFT PROVIDES POSITIVE PROTECTION AGAINST ASYMMETRY OF LIFT DEVICES DURING CRITICAL PHASES OF FLIGHT; OR, IF CERTIFICATION IS BASED UPON DEMONSTRATED CONTROLLABILITY OF THE AIRCRAFT UNDER CONDITION OF ASYMMETRY, INSURE THAT ASYMMETRIC WARNING SYSTEMS, STALL WARNING SYSTEMS, OR OTHER CRITICAL SYSTEMS NEEDED TO PROVIDE THE PILOT WITH INFORMATION ESSENTIAL TO SAFE FLIGHT ARE COMPLETELY REDUNDANT. (Closed - Unacceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-100 |
| INITIATE AND CONTINUE STRICT AND COMPREHENSIVE SURVEILLANCE EFFORTS IN THE FOLLOWING AREAS (Closed - Unacceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-101 |
| ASSURE THAT THE MAINTENANCE REVIEW BOARD FULLY CONSIDERS THE FOLLOWING ELEMENTS WHEN IT APPROVES AN AIRLINE/MANUFACTURER MAINTENANCE PROGRAM (Closed - Unacceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-102 |
| REQUIRE THAT AIR CARRIER MAINTENANCE FACILITIES AND OTHER DESIGNATED REPAIR STATIONS (Closed - Unacceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-103 |
| REVISE 14 CFR 121.707 TO MORE CLEARLY DEFINE "MAJOR" AND "MINOR" REPAIR CATEGORIES TO INSURE THAT THE REPORTING REQUIREMENT WILL INCLUDE ANY REPAIR OF DAMAGE TO A COMPONENT IDENTIFIED AS "STRUCTURALLY SIGNIFICANT." (Closed - Unacceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-104 |
| EXPAND THE SCOPE OF SURVEILLANCE OF AIR CARRIER MAINTENANCE BY (Closed - Unacceptable Action) |
| Issued: 21-DEC-1979 | To: FAA | A-79-105 |
| REVISE OPERATIONAL PROCEDURES AND INSTRUMENTATION TO INCREASE STALL MARGIN DURING SECONDARY EMERGENCIES BY (Closed - Acceptable Action) |
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Plan
Ce plan montre l'aéroport de départ ainsi que la supposé destination du vol. La ligne fixe reliant les deux aéroports n'est pas le plan de vol exact.
La distance entre Chicago-O'Hare International Airport, IL et Los Angeles International Airport, CA est de 2783 km (1739 miles).