Date:	Monday 2 December 1985
Time:	06:34
Type:	Boeing 747-228B
Owner/operator:	Air France
Registration:	F-GCBC
MSN:	22427/485
Year of manufacture:	1980
Total airframe hrs:	22762 hours
Engine model:	General Electric CF6-50E
Fatalities:	Fatalities: 0 / Occupants: 282
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	Rio de Janeiro-Galeão International Airport, RJ (GIG) -   Brazil
Phase:	Landing
Nature:	Passenger - Scheduled
Departure airport:	Paris-Charles de Gaulle Airport (CDG/LFPG)
Destination airport:	Rio de Janeiro-Galeão International Airport, RJ (GIG/SBGL)
Investigating agency:	CENIPA
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Air France flight 091 was involved in runway excursion accident at Rio de Janeiro-Galeão International Airport, Brazil. The aircraft, a Boeing 747-200, took off from Paris-Charles de Gaulle Airport, France at 21:30 UTC on a flight to Santiago, Chile with en route stops at Rio de Janeiro and Buenos Aires, Argentina.
The flight to Rio de Janeiro took about eleven hours and was uneventful.
At 08:34 UTC the aircraft touched down on runway 14, 400 m from the threshold. After reversers were set, the aircraft deviated from the runway heading and at 2000 m from the threshold it veered off the right side of the runway.
The aircraft ran over the grass for 765 m, until passing over a drainage ditch and the load apron concrete step, where the landing gears folded aft with the left wing gear completely separating. On the load apron concrete the aircraft spun around for 275 m until stopping, after the left outboard wing section struck an illumination
stand.
For a few seconds engines 2, 3 and 4 kept running at maximum reverse thrust, while engine number one run operated at full forward thrust.
After the engines were shut down, the passengers evacuated using three of the aircraft's left hand side escape slides. The fire that started on the area near engines number 2 and 3 was extinguished by the airport fire fighters.
It appeared that the no. 1 engine throttle cable had broken, making it impossible for the flight crew to control engine power. The engine had accelerated to an unusually high level of (forward) thrust (above takeoff power).

Contributing Factors
(1) Human Factor
Physiological Aspect - The crewmembers physical conditions (fatigue) might have contributed to their delay in perceiving the engine failure and to the inadequate reactions during the emergency.
(2) Material Factor
a) The hydraulic pump ripple of the CF6-50E engine caused considerable vibration on the pulley support region, which worked as a dynamic source to produce cable oscillation and relative movement between cable and pulley.
b) Pulley bracket design deficiency, possibly related to the reduced contact area between cable and pulley, allowing for the wearing of these components in the presence of abrasive agents, in association with the vibration on that area, knowing that there is localized contact between both (at the same points) in an almost permanent way (93% of the engine operating time in cruise range).
c) The tests performed by the Manufacturer confirmed the existing relative movement between cable and pulley, even after the introduction of modifications.
(3) Maintenance Deficiency
a) The use of an aluminum pulley, not authorized by the manufacturer as a substitution to the recommended phenolic pulley, made possible the formation of the abrasive agent (alumina).
b) The inadequate fixation of the pulley bracket due to the use, by the operator, of a screw of insufficient length for an additional washer, left loose the support side brace, allowing for the increase of the relative movement. already existing at that region, between cable and pulley.
(4) Flight Manual Deficiency
a) The 8-747 AFM instructions allow the pilot flying to apply reverse thrust before knowing the effective transit of reversers.
b) The 8-747 AFM has no instruction regarding a failure of reverser deployment
associated with an engine runaway fOrNard thrust. The lack of instructions on
this specific kind of abnormality, contributed to the crew not noticing that the
failure had occurred.
(5) Training Requirement Deficiency
The lack of simulator training requirement for this type of emergency contributed to the control loss.
(6) Crewmember Factor due to Operational Error
a) The captain did not observe the AFM instructions about the reverse levers and manual brake use.
b) The FIE did not observe the AFM instru ctions about the correct engine instrument monitoring during the reverse operation.

08:00 UTC / 06:00 local time:
METAR SBGL 0800Z 33003 CAVOK 20/19 1012 2AC080

08:35 UTC / 06:35 local time:
METAR SBGL 0835Z 35004 7000 10BR 1SC015 20/18 1012 VIS N/SE 9999

09:00 UTC / 07:00 local time:
METAR SBGL 0900Z 36004 6000 10BR 1SC015 21/19 1013 VIS NW/N 9999

Jornal do Brasil - 3 December 1985

photo (c) Alberto Bertoni; Rio de Janeiro-Galeao International Airport, RJ (GIG); 02 December 1985

photo (c) Alberto Bertoni; Rio de Janeiro-Galeao International Airport, RJ (GIG); 02 December 1985

photo (c) Alberto Bertoni; Rio de Janeiro-Galeao International Airport, RJ (GIG); 02 December 1985

photo (c) Alberto Bertoni; Rio de Janeiro-Galeao International Airport, RJ (GIG); 02 December 1985

photo (c) via Werner Fischdick; Nice-Côte d'Azur Airport (NCE); April 1985

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