|University of Bielefeld - Faculty of technology|
Networks and distributed Systems
Research group of Prof. Peter B. Ladkin, Ph.D.
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Washington, D.C. 20694
December 28, 1995
The Director General of Civil Aviation of Colombia has requested that the National Transportation Safety Board make the following information available to the news media. This information was released today by the Government of Colombia in connection with the investigation of the December 20, 1995, American Airlines flight 965 accident near Buga, Colombia.
The accident investigation is being conducted by the Colombian officials in accordance with the provisions of Annex 13 to the Convention on International Civil Aviation. Under those provisions, the U.S. team, led by Safety Board investigators, is participating fully in the investigation. The U.S. team includes advisors from the Federal Aviation Administration, American Airlines, Allied Pilots Association, and Boeing Commercial Airplane Company. The U.S. team participated fully in the development of the factual material contained in the attached Colombian press release.
Media inquiries about this investigation should continue to be directed to the Colombian civil aviation authorities.
Colombian Press Release--Factual Data
Aircraft Accident Investigation
American Airlines, Flight 965, Boeing 757, N651AA, Near Buga, Columbia, December 20, 1995
On December 20, 1995, at about 2138 EST, American Airlines, Flight 965, a regularly scheduled passenger flight from Miami, FL to Cali, Columbia, with 156 passengers and 8 crewmembers aboard, crashed into mountainous terrain during a descent under instrument flight rules 38 miles north of Cali. Four passengers survived.
The flight had made initial radio contact with the Cali Approach Control while descending to flight level 200 (20,000 feet) about 63 miles north of the Cali VOR. The flight was subsequently cleared to the Cali VOR, to descend and maintain one five thousand feet. The barometric altimeter setting was reported as 30.02 Hg and the flight was told that no delay was expected for the approach. It was also told to report the Tulua VOR, an en route navigational aid for an instrument approach procedure and landing at Cali.
As of 27 December 1995 Investigators have:
Successfully downloaded the DFDR for the final 30 minutes of flight AA 965
Reviewed data for parameters applicable to the investigation
Auditioned and transcribed the CVR tape, which was of good quality; the tape is 30 minutes and 36 seconds in duration
The data show:
Extended discussion of a non-pertinent nature (flight attendant crew duty time) prior to descent
No indication of descent checklist procedures
No indication of an arrival (approach) procedures briefing
No indication of any aircraft systems or powerplants malfunction
No indication of any unusual meteorological event, i.e. turbulence, wind shear
No indication of any external hostile force acting on the aircraft (subversion or terrorism)
No indication of any out-of-service condition of any applicable ground based navigational aids
Radio communications were accomplished from the left seat of the cockpit without evidence of language difficulty by either the flightcrew or the ATC controller
Flight 965 was operating in a radar surveillance environment until a few minutes before the end of the flight when radar coverage was no longer available
Flight 965 was on autopilot-L-NAV mode, southbound in the Bogota flight information region (FIR) on a direct route from BUTAL to Tulua (ULQ)
Following a position report from the airplane at 63 DME, Cali Approach Control issued the following clearance, "cleared to Cali VOR, descend and maintain 15 thousand feet, altimeter 3002, no delay expected for approach, report Tulua VOR" The flightcrew replied, "OK, understood cleared direct to Cali VOR, report Tulua and altitude 15, that's fifteen thousand, 3002, is that all correct Sir?
Approach replied, "Affirmative"
About two minutes later, Cali approach transmitted, "Okay Sir, the wind is calm, are you able to approach runway 19?
The flightcrew replied, "Ah, yes sir, we'll need a lower altitude right away though"
Approach replied, "Roger 965 is cleared to the VOR DME approach runway one niner, ROZO Number One arrival, report Tulua VOR"
The flightcrew readback was, "Cleared the VOR DME one niner ROZO one arrival, we'll report the VOR, thank you Sir"
Cali approach immediately clarified with, "Report Tulua", and the flightcrew immediately acknowledged, "Report Tulua"
The flightcrew referred to the cockpit chart package (approach publications) after ATC instructions to "Report Tulua"
Flightcrew discussion took place about the navigational aids to be used in the ROZO 1 Arrival, specifically their position relative to Tulua
About 30 seconds later the flightcrew requested, "Can American Airlines 965 go direct to ROZO and then do the ROZO arrival sir?"
Several radio transmissions then took place: Approach replied, "affirmative direct ROZO one and then runway one niner, the winds calm". The flightcrew replied, "all right, ROZO, the ROZO 1 to 19, thank you, American 965. And the controller stated, "Affirmative, report Tulua and twenty one miles, 5000 feet". The flightcrew acknowledged, "OK report Tulua, twenty one miles at 5000 feet, American 965"
DFDR information indicates that, at a point south of Tulua, while continuing descent, the flightcrew selected ULQ in the flight management system and the aircraft made a left turn of about 90 seconds to an easterly heading
Flightcrew discussion took place during this turn regarding a return to the centerline of the approach course, and then also to selection of a course direct to the ROZO radio beacon
DFDR information indicates that, while continuing the descent, the autopilot mode was switched to HDG SEL and the aircraft entered a right turn to a southwesterly heading to the end of the recorded data
Nine seconds prior to end of the recordings, data indicates a ground proximity warning system (GPWS) "TERRAIN" mode warning, then "PULLUP" warnings continue to the end of data
Data indicates the crew initiated a GPWS escape maneuver with increased engine power and airplane pitch attitude two seconds after the initial GPWS alert
The stick shaker activated during the GPWS escape maneuver During the GPWS maneuver, the flight spoilers, which had been extended during the descent, remained in the extended position to the end of the recorded data
Cap. German Duarte P.
Jefe Oficina de Control y
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|Peter B. Ladkin, 1999-02-08|
by Michael Blume