Cali Accident Report
University of Bielefeld&-& Faculty of technology
Networks and distributed Systems
Research group of Prof. Peter B. Ladkin, Ph.D.
AA965 Cali
Accident Report
Near Buga, Colombia, Dec 20, 1995
Prepared for the WWW by
Peter Ladkin
Universit&t Bielefeld
Prepared November 6, 1996
[Preparer's Note: Footnote markers are written in square brackets, e.g.,
[22], and footnotes appear denoted by the same figures in brackets at the
bottom of the same page, separated from the page contents by a dashed line.
Typographical errors have been retained in the
original as far as possible, except for occasional double full stops at
the ends of some paragraphs. PBL]
AERONAUTICA CIVIL
of THE REPUBLIC OF COLOMBIA
SANTAFE DE BOGOTA, D.C. - COLOMBIA
AIRCRAFT ACCIDENT REPORT
CONTROLLED FLIGHT INTO TERRAIN
AMERICAN AIRLINES FLIGHT 965
BOEING 757-223, N651AA
NEAR CALI, COLOMBIA
DECEMBER 20, 1995
Final Report of Aircraft Accident
American Airlines flight 965, December 20, 1995
1.FACTUAL INFORMATION
1.1 History of Flight 1
1.2 Injuries to Persons
1.3 Damage to Aircraft 5
1.4 Other Damage
Personnel Information 5
1.6 Airplane Information 9
1.7 Meteorological Information 10
1.8 Aids to Navigation 11
1.9 Communications 11
1.10 Aerodrome Information
1.11 Flight Recorders 12
1.12 Wreckage and Impact Information 13
1.13 Medical and Pathological Information14
1.14 Fire15
1.15 Survival Aspects15
1.16 Tests and Research15
1.17 Organizational and Management Information21
1.18 Additional Information22
2. ANALYSIS
2.1General 28
2.2The Decision to Accept Runway 19 29
2.3Situational Awareness 32
2.4Awareness of Terrain 35
2.5Automation40
2.6Crew Resource Management46
2.7Speedbrakes48
2.8The Cali Approach Controller49
2.9FAA Oversight51
2.10GPWS Escape Maneuver51
2.11Recording of FMS Data54
3CONCLUSIONS
3.1Findings55
Probable Cause57
3.3Contributing Factors57
4RECOMMENDATIONS58
5APPENDIXES
Appendix A--Investigation62
Appendix B-- Cockpit Voice Recorder Transcript63
Appendix C--Cali Approach Charts64
Appendix D--American Airlines Ops. Manual page65
Appendix E--Photos of Wreckage66
Appendix F--Route Pages Prior to Impact67
AIRCRAFT ACCIDENT REPORT
AERONAUTICA CIVIL OF THE REPUBLIC OF COLOMBIA
SANTAFE DE BOGOTA, D.C. - COLOMBIA
CONTROLLED FLIGHT INTO TERRAIN
AMERICAN AIRLINES FLIGHT 965, BOEING 757-223, N651AA
NEAR CALI, COLOMBIA, DECEMBER 20, 1995
1. FACTUAL INFORMATION
History of Flight
At 2142 eastern standard time (est) [l], on December 20, 1995, American
Airlines Flight 965 (AA965), a Boeing 757-223, N651AA, on a regularly
scheduled passenger flight from Miami International Airport (MIA),
Florida, U.S.A., to Alfonso Bonilla Aragon International Airport
(SKCL), in Cali, Colombia, operating under instrument flight rules
(IFR), crashed into mountainous terrain during a descent from cruise
altitude in visual meteorological conditions (VMC). The accident site
was near the town of Buga, 33 miles northeast of the Cali VOR [2]
(CLO). The airplane impacted at about 8,900 feet mean sea level (msl),
near the summit of El Deluvio and approximately 10 miles east of
Airway W3. Of the 155 passengers, 2 flightcrew members, and 6
cabincrew members on board, 4 passengers survived the accident.
On the previous flight under a different crew, the airplane arrived at
MIA from Guayaquil, Equador, at 1438, on December 20, 1996. The
Guayaquil to MIA flightcrew reported that there were no significant
maintenance or operations-related discrepancies on the airplane. The
captain and first officer of AA965 (MIA to SKCL) arrived at the
airline's MIA operations office about 1 hour before the proposed
departure time of 1640. The operations base manager later stated that
----------------
[1] All times herein are expressed in est, based on the 24-hour clock, unless
otherwise indicated. The Colombian and MIA local time was the same (est).
[2] Very high frequency (VHF) omni-directional radio range.
both the captain and first officer were in his office about 40 minutes
before the required check-in time, and appeared to be in good spirits.
According to the AA flight dispatcher at MIA, AA965 was delayed about
34 minutes, waiting for the arrival of connecting passengers and
The flight departed the gate at 1714, and then experienced
another ground delay of 1 hour 21 minutes that the flight dispatcher
stated was related to gate congestion due to airport traffic. AA965
departed MIA at 1835, with an estimated time enroute to Cali of 3 hour
12 minutes.
AA965 was cleared to climb to flight level (FL) 370 [3]. The route of
flight was from MIA through Cuban airspace, then through Jamaican
airspace, and into Colombian airspace, where the flight was recleared
by Barranquilla Air Traffic Control Center (Barranquilla Center) to
proceed from KILER Intersection direct to BUTAL Intersection. The
flight then passed abeam Cartegena (CTG). Bogota Center subsequently
cleared the flight to fly direct from BUTAL to the Tulua VOR (ULQ)
At 2103, AA965 estimated to Bogota Center that they would cross BUTAL
at 2107. As AA965 passed BUTAL, Bogota Center again cleared the flight
from its present position to ULQ, and told the flight to report when
they were ready to descend. At 2110, AA965 communicated via ACARS [4]
with AA's System Operations Control (SOC) center, asking for weather
information at Cali. At 2111, Cali weather was reported as clear,
visibility greater than 10 kilometers, and scattered clouds. At
2126:16, AA965 requested descent clearance. The flight was initially
cleared to FL 240 and then to FL 200. At 2134:04, the flight was
instructed to contact Cali Approach Control (Approach).
AA965 contacted Approach at 2134:40. The captain, making the radio
transmissions [5] said, "Cali approach, American nine six five." The
approach controller replied, "American niner six five, good
evening. go ahead." The captain stated, "ah, buenos noches senor,
American nine six five leaving two three zero, descending to two zero
zero. go ahead sir." The controller asked, "the uh, distance DME [6] from
Cali?" The captain replied, "the DME is six three." The controller
----------------
[3] 37,000 feet. Flight levels are expressed in hundreds of feet above msl.
[4]Aircraft Communications Addressing and Reporting System.
[5] Based on the air traffic control (ATC) and cockpit voice
recordings (CVR), the captain made the radio communications and the
first officer was at the controls of the airplane.
[6]Distance measuring equipment, providing a display in nautical miles.
then stated, "roger, is cleared to Cali VOR, uh, descend and maintain
one, fve thousand feet. altimeter three zero zero two.... no delay
expect for approach.
report uh, Tulua VOR." The captain replied, "OK,
understood. cleared direct to Cali VOR. uh, report Tulua and altitude
one five, that's fifteen thousand three zero.. zero.. two. is that all
correct sir?" The controller stated, "affirmative." The captain
replied at 2135:27, "Thank you. At 2135:28, the captain informed the
first officer that he had "...put direct Cali for you in there." [7]
At 2136:31, Approach asked AA965, "sir the wind is calm. are you able
to [execute the] approach [to] runway one niner?" (see approach
charts, appendix C, "VOR DME Rwy 19" and "ILS RWY 01") The captain
responded, "uh yes sir, we'll need a lower altitude right away
though." The approach controller then stated, "roger. American nine
six five is cleared to VOR DME approach runway one niner. Rozo number
one, arrival. report Tulua VOR." The captain, replied, "cleared the
VOR DME to one nine, Rozo one arrival. will report the VOR, thank you
sir." The controller stated, "report uh, Tulua VOR." The captain
replied, "report Tulua."
At 2137:29, AA965 asked Approach, "can American airlines uh, nine six
five go direct to Rozo and then do the Rozo arrival sir?" The Cali
approach controller replied, "affirmative. take the Rozo one and
runway one niner, the wind is calm." The captain responded, "alright
Rozo, the Rozo one to one nine, thank you, American nine six five."
The controller stated, "(thank you very much) [8]....
report Tulua and
e'eh, twenty one miles ah, five thousand feet." The captain responded,
"OK, report Tulua twenty one miles and five thousand feet, American
nine uh, six five."
At 2137, after passing ULQ [9], during the descent, the airplane began to
turn to the left of the cleared course and flew on an easterly heading
for approximately one minute. Then the airplane turned to the right,
while still in the descent. At 2139:25, Morse code for the letters
"VC" was recorded by navigation radio onto the airplane's CVR. At
2139:29, Morse code similar to the letters "ULQ" was recorded. At
2140:01, the captain asked Approach, "and American uh,
----------------
[7] A reference to the airplane's flight management system (FMS).
[8] "Questionable insertion" transcribed during hearing of the tape by CVR
invest1gators.
[9]Position based on ATC and CVR recordings, flight data recorder
(FDR) information, time and distance measurements, and reconstructed
data from the airplane's flight management computer (FMC). (see
section 1.16).
thirty eight miles north of Cali, and you want us to go Tulua and then
do the Rozo uh, to uh, the runway, right to runway one nine?" The
controller answered, "...you can [unintelligible word] landed,
runway one niner, you can use runway one niner.
what is (you)
altitude and (the) DME from Cali?" The flight responded, "OK, we're
thirty seven DME [10] at ten thousand feet." The controller stated at
2140:25, "roger.
report (uh) five thousand and uh, final to one one,
runway one niner."
The CVR recorded the flightcrew's conversations as well as radio
transmissions. At 2140:40, the captain stated, "it's that [expletive]
Tulua I'm not getting for some reason. see I can't get. OK now,
no. Tulua's [expletive] up." At 2140:49 the captain said, "but I can
put it in the box if you want it." The first officer replied, "I don't
want Tulua. let's just go to the extended centerline of uh...." The
captain stated, "which is Rozo." At 2140:56, the captain stated, "why
don't you just go direct to Rozo then, alright?" The first officer
replied, "OK, let's...The captain said, "I'm goin' to put that over
you." The first officer replied, "...get some altimeters, we'er out of
uh, ten now."
At 2141:02, Cali Approach requested the flight's altitude. The flight
replied, "nine six five, nine thousand feet." The controller then
asked at 2141: 10, "roger, distance now?" The flightcrew did not
respond to the controller. At 2141:15, the CVR recorded from the
cockpit area microphone the mechanical voice and sounds of the
airplane's ground proximity warning system (GPWS), "terrain, terrain,
whoop, whoop." The captain stated, "Oh [expletive]," and a sound
similar to autopilot disconnect warning began. The captain said,
"...pull up baby." The mechanical voice and sound continued, "...pull
up, whoop, whoop, pull up." The FDR showed that the flightcrew added
full power and raised the nose of the airplane, the spoilers
(speedbrakes) that had been extended during the descent were not
retracted. The airplane entered into the regime of stick shaker stall
warning, nose up attitude was lowered slightly [11], the airplane came
out of stick shaker warning, nose up attitude then increased and stick
shaker was reentered. The CVR ended at 2141 :28.
The wreckage path and FDR data evidenced that the airplane was on a
magnetic heading of 223 degrees, nose up, and wings approximately
level, as it struck trees at about 8,900 feet msl on the east side of
El Deluvio. The airplane
----------------
[10] 37 DME north of the Cali VOR (CLO) places the airplane 6 miles
south of ULQ and 28 miles north of the approach end of runway 19 at
[11] From FDR data.
continued over a ridge near the summit and impacted and burned on the
west side of the mountain, at 3 degrees 50 minutes 45.2 seconds north
latitude and 76 degrees 6 minutes 17.1 seconds west
longitude. Approach unsuccessfully attempted to contact AA965 several
times after the time of impact (see appendix D, two photographs of the
accident site).
1.2 Injuries to Persons
Injuries FlightcrewCabincrewPassengersTotal
Damage to Airplane
The airplane was destroyed.
Other Damage
None. Impact was in tree-covered mountainous terrain.
Personnel Information
The captain and first officer were certified by the U.S. Federal
Aviation Administration (FAA) to hold their respective positions in
the Boeing 757 (B-757) and each possessed a current first class
medical certificate. FAA records showed that neither had been involved
in an accident, incident, or enforcement action.
Cockpit Crew
Pilot In CommandFirst Officer
Date of Birth
Date of Hire with American Airlines 9/22/6910/11/86
First Class Medical Certificate Issued 12/7/95
Approximate Total Flying Time13,000 hrs 5,800 hrs
Total on Type (B757/B767)
Total hrs last 90 Days
Total hrs last 60 Days
Total hrs last 30 Days
Total Last 7 Days
Accident Flight hrs (est.)
Hours On Duty Prior to Accident
Hours Off Duty Prior to Work Period120+ (5 days)120+(5 days)
The captain began flying as a civilian student pilot in September
He then joined the U.S. Air Force, became an Air Force pilot
and flew a variety of military airplanes including fighters and
4-engine transport airplanes in domestic and foreign operations
through 1969. He became employed by AA on September 22,
1969. Employment records at AA indicated that he had acquired about
2,698 flight hours before being hired, and all except 36 hours were
with the U.S. Air Force. His service at AA began as a B-727 flight
engineer. As flew as captain on the B-727, -757 and -767 [12].
The captain underwent his last proficiency check in a flight simulator
on April 28, 1995. AA referred to this check as the "R2" check or the
"simulator check." The check ended a S-day training and checking
sequence in which other annual requirements were also met, including
training regarding security and hazardous materials, crew resource
management (CRM), and international operations. The captain completed
annual line checks, administered by an AA FAA-approved check airman on
November 9, 1995 (domestic) and on December 9, 1995
(international). In the line check on December 9, 1995, he flew as
captain on AA965 from MIA to SKCL. Including flights to SKCL on
December 9, and December 14, 1995, the captain flew a total of 13
times into Cali before the accident flight.
----------------
[12] The FAA awards common type ratings to pilots qualifying on the B-757
and -767 because of the similarities between the two
airplanes. B-757/767 type rated pilots for AA and other airlines may
serve on both airplane types equally, without need of additional
certification.
The captain's last medical examination was on December 7, 1995, when
his Class I medical certificate was renewed. His certificate bore the
following limitation: "Holder shall wear lenses that correct for
distant vision and possess glasses that correct for near vision while
exercising the privileges of this airman certificate."
The captain was described by his colleagues as a non-smoker, avid
tennis player, in exemplary health, and respected for his professional
skills, including his skill in communicating with crewmembers and
passengers. Company records contained numerous letters from passengers
and company employees that reflected outstanding and courteous
performance. The captain was married and had two adult children who
lived outside of the home.
On the day of the accident, December 20, 1995, the captain arose
around 0500. His wife began to prepare for a trip in her capacity as
an AA flight attendant. She was later not sure whether the captain had
returned to sleep after she departed their home at 0600. She estimated
that he departed from home about 1200 for the drive to MIA.
The day prior to the accident, December 19, the captain awoke about
0700, and spent the day relaxing around the house and then playing
tennis about l 1/2 hours with his wife. They returned home about
2130. From December 15 through 18, the captain and his wife visited
his family in New Jersey, on what was described as an enjoyable
Christmas visit that they took early because of the scheduled trips.
First Officer
The first officer began his flying eareer as a college undergraduate
by enrolling in the U.S. Air Force Reserve Officer Training Corps. He
began pilot training with the Air Force in 1979, flying a variety of
aircraft, including trainers and F-4E fighters, through 1986. He
served as an instructor in ground school, in flight simulators, and in
airplanes, and in 1985 was awarded Air Force Instruetor of the Year.
The first officer beeame employed by AA on Oetober 11, 1986.
reeords indicated that he had accumulated a total of 1,362 flight
hours when hired. He began as a flight engineer on the B-727. Later
duties included first
officer on the B-727, McDonnell Douglas (MD) 11, and B-757 and -767. He
possessed type ratings in the MD 11 and B757/B767.
The first officer attended the AA 5-day qualification and recurrence
course and satisfactorily completed the required annual simulator
check on November 27, 1995. As part of that sequence, annual recurrent
requirements also ineluded training regarding security, hazardous
materials, CRM, and international operations. The first officer's
annual line cheek was aeeomplished on August 31, 1995.
The first offieer's Class 1 medical certificate was renewed on June 21,
1995, with no limitations.
The first officer had never flown into Cali. However, he had flown to
other destinations in South America as an internationally qualified
B-757/767 first officer.
The first officer was described by his colleagues as professionally
competent, and appropriately assertive as a flightcrew member. He was
married and the father of three young children who lived at home.
On the day of the accident, the first officer arose about 0700, and
had breakfast with his family. Around 0830, he worked with his wife to
prepare for their children's home schooling aetivities. He later
exercised. He visited with his father and family around midday and,
around 1230, left for the airport at Orlando, Florida, for the flight
On the day prior to the accident, December 19, the first officer arose
about 0700, and had an 0830, appointment with an aviation medical
examiner (AME) for a flight physical [13]. Afterwards, the first officer
visited with his brother at his brother's place of business, and later
the two had lunch. The first officer returned home at 1530, and played
basketball with his children. The family had dinner about 1730, and at
1900, he, his wife, and children attended a basketball game where
their son was playing. The family returned home about 2015, and at
2115 the first officer helped put the children to bed. He and his wife
watched television briefly and retired about 2330.
----------------
[13] The AME later stated that the first officer was found in excellent health.
On December 18, the first officer arose about 0715, and after
breakfast exercised at the local YMCA. He assisted his wife in home
schooling their children and then had lunch with his wife. After
shopping for holiday gifts, they took the children to a restaurant for
dinner and returned home about 2100.
Airplane Information
The airplane, a Boeing 757-223, serial no. 24609, was operated by AA
since new on August 27, 1991. The airplane was owned by Meridian Trust
Company of Reading, Pennsylvania, U.S.A., and leased to the airline.
Before the accident flight, the airplane accumulated 13,782 flight
hours and 4,922 cycles. The airplane was equipped with two RB-211 535E
4B Rolls Royce turbofan engines. The left engine, serial no. 31146,
accumulated 10,657 hours and 3,768 cycles. The right engine, serial
no. 31042, had accumulated 13,274 total hours and 4,966 cycles.
There were no malfunctions or outstanding maintenance items on the
airplane prior to its departure from MIA on December 20, 1995. The
airplane received a B-level maintenance check (B-check) in November
1995, and all subsequent required maintenance checks were
performed. In addition, there was no record of repetitive navigation
or flight control system anomalies.
Weight and Balance Information
The airplane weight and balance was determined by AA's dispatch center
at Dallas/Ft. Worth International Airport (DFW), Texas, U.S.A. The
airplane was loaded with 43,300 pounds of fuel for takeoff from MIA on
December 20, 1995. Its takeoff gross weight was calculated as 209,520
pounds. The airplane's center of gravity (c.g.) at takeoff was
determined to be 25.2 percent mean aerodynamic chord (MAC). The gross
weight and c.g. were within limits for takeoff.
Estimated flight plan calculations indicated that the airplane
consumed 26,620 pounds of fuel prior to impact. Its impact gross
weight was 182,900 pounds and its c.g. was 23.8 percent MAC. The final
gross weight and c.g. were within landing limits.
Flight Management System
The B-757 and -767 are flight management system (FMS)-equipped
airplanes. The accident airplane incorporated an FMS that included an
flight management computer (FMC), a worldwide navigation data base
that contained radio frequencies, and latitude and longitude
coordinates of relevant navigation aids as well as coordinates of
airports capable of B-757 operations. The FMC data base also included
B-757 performance data which, combined with pilot inputs, governed
autothrottle and autopilot functions. The FMS monitored the system and
engine status and displayed the information, as well as airplane
attitude, flightpath, navigation, and other information, through
electronically-generated cathode ray tube (CRT) displays [14].
Pilot input into the FMS could be performed either through a keyboard
and associated cathode ray tube (CRT), known as a control display unit
(CDU), or through more limited FMS input via controls on the
glareshield (see section 1.16, regarding post-accident testing of FMS
components).
Meteorological Information
The flight crew received the following AA terminal weather forecast
for Cali in the flight dispatch records:
Cali at 0606 universal coordinated time (utc) [15]: Winds calm, visibility
more than 10 kilometers, clouds scattered at 2,500 and 10,000 feet
Temporary change (Cali) from 0900 to 1300 utc: 8000 meters visibility,
rain showers in the vicinity, clouds scattered at 2,000, broken at
8,500 feet
Temporary change (Cali) from 2000 through 0200 utc: Winds 360 degrees
at 05 knots, rain showers in the vicinity, clouds scattered at 2,000
feet and broken at 8,000 feet
The flight departure paper recorded the weather at 1500 est as: Winds
calm, visibility more than 10 kilometers, clouds scattered at 2,000
and 12,000 feet,
----------------
[14] On the instrument panel before each pilot
[15] Universal coordinate time. Est is 5 hours behind utc.
temperature 28 centigrade, dew point 18 degrees centigrade (C.),
altimeter (QNH) 29.94 inches of mercury
The flight crew received an updated weather message via the ACARS.
The weather was for 1700 est and was reported as:
(Cali): Winds 340 degrees at 06 knots, visibility more than 10
kilometers, rain showers in the vicinity, clouds scattered at 1,700
feet and broken at 10,000 feet, temperature 28 degrees C., dew point
18 degrees C., altimeter (QNH) 29.98 inches of mercury
Enroute, the flight crew requested the Cali weather via ACARS at 2050
est. The company replied at 2051, via ACARS, that there was "no
current data."
At 2110 est, the flightcrew requested, again, the weather for Cali. At
2111, the flightcrew received via the uplink, the following weather
information for 2000 local at Cali: Winds 160 degrees at 04 knots,
visibility more than 10 kilometers, clouds scattered at 1,700 and
10,000 feet, temperature 23 degrees and dew point 18 degrees C.,
altimeter (QNH) 29.98 inches of mercury. This was the last request and
uplink of weather recorded.
Aids to Navigation
There were no difficulties with aids to navigation.
Communications
There were no difficulties with communications equipment.
Aerodrome Information
Alfonso Bonilla Aragon Airport (SKCL) in Cali, is located in a long,
narrow valley oriented north to south. Mountains extend up to 14,000
feet msl to the east and west of the valley. The airport is located
approximately 7.5 miles north of CLO, at an elevation of 3,162 feet
At the time of the accident, the airport control tower operated 24
hours a day, controlling departing and arriving traffic to runways 01
and 19. The runway was hard surfaced, 9,842 feet long, and 148 feet
wide, with a parallel taxiway running the full length. Runway 01 had
instrument landing system (ILS) CAT 1 and VOR/DME approaches
available. The ILS has a 2.5 degree glide slope, with precision
approach path indicator (PAPI) visual glide path lighting to match the
2.5 degree electronic glide slope. Runway 19 had a VOR/DME approach
available and the lighting included a PAPI system with a 3.0 degree
glide path. Two standard arrivals (STARs) were available, one from the
north of the airport (ROZO 1) and one from the east (MANGA 1). There
were 12 published departures available.
Radio navigation facilities included the ILS (IPAS), the Cali VOR
(CLO), Rozo NDB (R), the middle marker (AS), and the Cali NDB (CLO). The
Tulua VOR (ULQ) was approximately 33 nautical miles north of the airfield (43
DME from CLO), and was the initial point depicted on the ROZO 1 arrival.
The airport was served by Cali Approach. No approach control radar
was available.
The field report recorded in the AA dispatch records
indicated that runways 01 and 19 were open and dry. There were three
notices to airmen (NOTAMS) in the flight departure papers, they were:
1. Until further notice, runway 01 LM/AS frequency 240
Mhz ops on test period.
2. Fire and rescue services downgrades to VII cat.
3. Until further notice, MER/NDB 1.685 Khz inop.
Flight Recorders
1.11.1 Flight Data Recorder
The airplane was equipped a Sundstrand digital FDR, serial
FDR recorded parameters included: radio
autothrottle and
ground proximity warning
and parameters indicating flight control position, including
brake deployment. The data were recorded on a continuous 25 hour cycle
in which the oldest data were erased and new data recorded.
The FDR was extensively damaged by impact forces. There was
no evidence of fire damage to the recorder. The tape recording medium
was undamaged. The FDR was brought to the U.S. National Transportation
Safety Board's (NTSB's) laboratories in Washington, D.C., U.S.A., and
1.11.2 Cockpit Voice Recorder
The airplane was equipped with a Fairchild model A-lOOa CVR, serial
no. 59225. Examination in the NTSB CVR laboratory found exterior structural
damage. The exterior case was cut away to access the tape medium. The tape did
not sustain heat or impact damage. The recording was of good quality and a
transcript was prepared of the entire 30:40 minute recording.
Wreckage and Impact Information
The airplane struck near the top of a mountain ridge about
35 miles northeast of Cali. The elevation of the top of the ridge was
about 9,000 feet mean sea level. The airplane initially struck trees
on the east side of the ridge, and the preponderance of the wreckage,
which contained the occupants of the airplane and included both
engines, came to rest on the west face of the ridge. There was no
indication of in-flight fire or separation of parts before initial
The initial impact area was marked by an area of broken
trees, followed by a swath where the trees had been essentially
flattened or uprooted. The area of uprooted trees began about 250 feet
below the top of the ridge. The initial impact swath was oriented
along a heading of about 220°. Wreckage that was found at the
beginning of the wreckage path included thrust reverser parts, a fan
cowling, an APU tail cone, flap jackscrews, an engine fire bottle, the
FDR, and a small section of wing. The pattern of the broken trees
indicated that the airplane initially struck at a high nose up
The main wreckage came to rest on the west side of the
ridge, about 400 to 500 feet from the top. In addition to the engines,
the largest portion of wreckage included the cockpit, a section of
center fuselage about 35 feet long, the CVR, aviation electronics
(avionics) boxes, a section of the aft fuselage, and a portion of the
wing center section.
The wreckage evidence indicated that both flaps and landing
gear were in the retracted position at the time of impact.
Both engines were examined on site. The left engine showed
ingestion of soil and foliage as far aft as the inlet guide vanes to
the intermediate compressor section. There was a substantial bending
of fan blades in a counter-clockwise direction, with some bent
clockwise.
The right engine was found slightly buried into the
ground. The blade damage that was observable was similar to the damage
observed on the left engine.
Soil and foliage were found as far aft
as the inlet to the intermediate compressor section. Neither engine
showed evidence of fire damage.
Numerous cireuit cards and other parts that were onsidered
likely to contain non-volatile memory were retrieved from the site,
packed in static free material, and shipped to the United States for
read out at the facilities of their manufacturers. With the exception
of one circuit card from the Honeywell- manufaetured FMC, the material
either did not contain non-volatile memory or was too severely damaged
to permit data retrieval. Discussion of the data retrieval of the
non-volatile memory from the FMC is located in section 1.16, Tests and
Medical and Pathological Information
The body of the first officer was recovered on the first day
after the accident. The body of the captain was retrieved from the
crash site on the third day after the accident. The cause of death of
each was determined to be blunt force trauma.
Specimens of liver, blood, and vitreous humor were obtained
and analyzed by the Colombian Instituto Nacional de Medicina
Legal. The samples from the body of the first officer were found to be
negative for alcohol and drugs of abuse. The blood and liver samples
from the captain were found to be positive for alcohol at 0.074
percent and 0.35 percent blood alcohol levels, respectively, and
negative for drugs of abuse. Vitreous specimens were found to be
negative for both pilots.
Portions of the liver and blood samples from the bodies of
the flightcrew members were then flown to the United States to be
further analyzed by
the Forensic Toxicology Laboratory of the U.S. Armed Forces Institute
of Pathology. The analysis and subsequent reexamination of the results
of the analysis in Colombia indicated that the positive alcohol level
derived from post-mortem microbial action, and not from pre-mortem
alcohol ingestion.
The was no evidence preimpact fire or explosion. There was
limited postimpact fire, where the main fuselage came to rest.
Survival Factors
Search and rescue facilities coordinators around the Cali
and Buga area were notified of the missing flight at 2150 local
time. At 2230, the Civil Defense, Red Cross, Police and Army
contingencies were mobilized to the Buga general area where the
airplane was last reported. The initial sighting of the crash site was
made by a helicopter at 06:30, December 21, 1995. Search teams arrived
by helicopter to the crash site within a few minutes of the sighting.
The characteristics and magnitude of the impact and
subsequent destruction of the airplane indicated that the accident was
non survivable. However, 5 passengers initially survived the crash,
having sustained serious injuries. One died later in the hospital.
Postmortem examination of the occupants indicated that the
characteristics of the fatal and non fatal injuries varied according
to the location of the persons in the crashed airplane. All of the
injuries were consistent with deceleration trauma of different
intensity consistent with the aircraft's impact and breakdown
pattern. Because some passengers were found to have changed seats
within the airplane, evaluating individual injuries by seat assignment
was not successful.
Tests and Research
Follow-up examinations and testing were conducted regarding
aircraft systems, operations procedures, and human performance. These
were conducted in the United States at Flight Safety International
Academy in Miami, F Honeywell Air Transport Systems, in
Phoenix, A Jeppesen Sanderson
Company, in Englewood, C American Airlines in Fort Worth, T and
Boeing Commercial Airplane Group, in Seattle, Washington.
1.16.1 FMS Component Examinations
Portions of the FMS, including the FMC, that had been
recovered from the wreckage, were examined at Honeywell Air Transport
After the components were cleaned for laboratory
examination, it was found that the FMC contained a printed circuit
card that had two non-volatile memory integrated circuits. Data
recovered from the integrated circuits included a navigation data
base, guidance buffer, built in test equipment (BITE) history file,
operational program, and other reference information.
A load test of the FMC memory showed that the operational
software and navigational data were current for the time of the
accident. The BITE showed that there had been no recorded loss of
function during the last 10 flights of the airplane.
The guidance buffer recorded that the FMC-planned route of
flight at the point of power loss [16] was from the last passed waypoint,
shown as KILER, direct to the next waypoint that had not yet been
passed, shown as ULQ. The route beyond ULQ was shown as waypoint R,
then CLO, then CLO03 [17], then the stored ILS runway 01 approach of
CI01, then FI01, then RW01, then ROZO, then a hold [18] at ROZO.
When the FMC memory was first restored, a modification to
the above route was displayed. The modified route was shown as ULQ, a
ROUTE DISCONTINUITY message, then R, another ROUTE DISCONTINUITY
message, then CLO, then CLO03, then CI01, then FI01, then RW01, then
ROZO, then a hold at ROZO.
The FMC was put through a short term (power transient)
initialization and the captain's and first officer's CDU displays were
identical, as follows:
----------------
[16] Coinciding with the time of impact.
[17] CLO03 was found to be a point-bearing distance location.
[18] BITE provided non volatile memory of FMC activity for previous 10
flights of the accident airplane. Hold indicates routing to a
preplanned holding pattern location.
MOD RTE 1 LEGS1/2
R268/FL364
--ROUTE DISCONTINUITY -
CLO237/5510
161°3NM
CLO03207/5190
307°2NM
CI01189/5000
&ERASERTE DATA&
The CLO03 was not seen on a printed format of the route. When the (L4)
line select key (LSK) for CLO03 was pressed, the scratch pad area (LSK
L6) at the bottom of the screen was displayed:
CLO163.0/003.0
Pushing the NEXT PAGE button showed:
MOD RTE LEGS2/2
013°2NM
FI01170/5000
013°7NM
RW01130/3200
013°4NM
ROZO---/3560A
ROZO---/5000
&ERASE RTE DATA&
----------------
[19] The font size on the airspeeds and altitudes associated with CLO
and CLO03 were smaller than the font sizes of comparable information
for CI01. These differences indicate that the information for CI01 was
inputted by the pilot whereas the information for CLO were generated
by the FMS.
REF NAV DATA was displayed for the following points:
IDENTLATLONGFREQ
ULQN04degO5.8W076degl3.6
CLON03deg24.2W076deg24.6
CLO03 N03deg21.4 W076deg23.6
N03deg22.5 W076deg25.0
N03deg24.5 W076deg24.7
N03deg31.6 W076deg23.2
LENGTH=9842ft
N03deg35.8 W076deg22.5
N04deg40.7 W074deg06.3 [20]
N03deg32.8 W076deg23.1
KILER N15deO0.0 W076deg52.0
All of the above points were within 0.1 mile of their
location in the ARINC-424 [21] navigational data for December 21, 1995,
with the exception of RW01 at SKCL. However, it was found that the FMC
display showed the threshold of the runway and the ARINC-424 data
showed the touch-down point for the instrument landing system.
During testing at Honeywell Systems, the memory card from
the accident airplane was installed into an FMC that was programmed in
the AA configuration and run on an engineering simulator. Different
route modifications were executed and timed for delays after the
EXECUTE button was pushed. Over ULQ, inputting "direct" changes to
ROZO from different orientations, as well as to KILER, resulted in
execution delays of not more than approximately 2 seconds (see
appendix E, Reconstructed Route Pages from accident FMC).
At the completion of the tests, the memory card was returned
to the original FMC computer case that had been recovered from the
accident site. Dirt
----------------
[20] R refers to an NDB in Bogota, located about 130 miles
east-northeast of Cali.
[21] Aeronautical Radio. Inc. of Annapolis, Maryland).
was vacuumed from the interior of the FMC and brushed from the faces
of dirty circuit cards. Although a number of connector pins were found
broken from the dented rear face, they were then box mounted into the
simulator without difficulty and operated successfully.
1.16.2 At Jeppesen Sanderson
The Jeppesen Sanderson Company described that software
inputs that are provided by contract to operators of FMS-equipped
aircraft are made in accordance with the guidelines of ARINC-424
Chapter 7, "Naming Conventions, " establishes the coding rules of
identifiers and Name fields when government source data does not
provide these Identifiers or Names within the rules established by
International Civil Aviation Organization (ICAO) Annex 11. As stated
by the Jeppesen Sanderson Senior Vice President, Flight Information
and Technology, in a subsequent letter to the President of the
Investigation:
An important item to remember is that all of Jeppesen's
navigation data is entered into our database using the ARINC 424
Aeronautical Database Specifications standard. This standard is the
result of an effort that began in August 1973 and has been
continuously updated and now is in its 14th revision. The ARINC spec
is a set of rules that has been established by industry, airlines,
avionics manufacturers, FAA, ICAO, international AIS offices, and
others to ensure agreement in concept of using aeronautical
information in automated systems worldwide.
As one of the first considerations, databases cannot accept
duplicate information. There cannot be two names for the same item.
Specifically, the Romeo NDB uses the letter R for its identifier. The
Rozo NDB also uses the same letter R for its identifier. The letter R
was assigned to both of these navaids by the Colombian government.
Both of these navaids are within the same country and therefore
have the same ICAO identifier. For enroute facilities, the combination
of both the NDB identifier and [emphasis in original] the ICAO code is
normally adequate to provide uniqueness for entering data in the
When entering navaid information into the database, the navaid
identifier is used as the key identifier. This means that the letter R
is the default value for the Romeo NDB and the Rozo NDB. Since the
Bogota city and airport is larger than Cali, the larger airports are
entered sequentially at the beginning to satisfy the greatest amount
of users. The letter R was entered for the Romeo NDB as the "key" to
the navaid. Therefore, when using most FMSs, entering the letter R
when in Colombia will call up the Romeo NDB since it is the identifier
for the Romeo NDB.
When the Rozo NDB was entered into the database, the letter R was
attempted, but the computer rejected the letter R since it had already
been used for the Romeo NDB. According to the ARINC 424 standards,
when a duplicate exists, the name of the NDB can be used as the
identifier for entry into the database. In the case of Rozo, since the
name is four letters or less, the complete name of Rozo was used as
the identifier. At Jeppesen, we are not experts on the use of FMSs,
but we understand the access to NDBs in most FMSs is via their
identifier.
In this case, an entry of the single letter R would
retrieve Rome since R is the identifier for Romeo. To retrieve the
Rozo NDB, the letters ROZO would need to be entered into the FMS since
that is the identifier for Rozo.
Under the NavData tab in the Jeppesen Airway Manual, there is an
explanation of most of the procedures specified in ARINC 424 as they
apply to the user of an FMS....
Following the examinations at Honeywell Systems and the
meehngs at Jeppesen Sanderson, tests were conducted at Boeing
Commercial Airplane Group, using a B-757 fixed base simulator as well
as a CDU/FMS bench-type simulator.
Several different displays were
used to replicate the flightpath and routing information that was
recovered from the accident FMC non volatile memory at Honeywell
Systems, and the accident flight's arrival, descent, approach phase,
and attempted escape maneuver were replicated as closely as possible
on the fixed-base simulator.
It was found that neither the Boeing fixed base simulator
nor the CDU/FMS simulator could be backdriven with the data obtained
directly from the accident airplane's FDR. Instead, data obtained from
the FDR and non volatile memory data from the FMC were input into both
simulators, to replicate the flight as closely as possible from 63
miles north of CLO to and including the escape maneuver. It was found
that calling up R on the CDU displayed a series of waypoints and their
coordinates. They were located north and south of the equator and
ordered from top to bottom of the display by their distance from the
Romeo, a non directional radio beacon (NDB) in the City of
Bogota, was the first and closest waypoint displayed. Rozo, which was
also an NDB, was not displayed, and entering R would not call up
Rozo. Rozo could only called up by spelling out ROZO on the CDU.
The Simulations found that when R was entered into the CDU,
a white dashed line pointed off the map display towards the
east-northeast. When R was "executed," the airplane turned towards R
(in the City of Bogota) and the white dashed line turned to a solid
magenta colored line on the display.
Investigators also attempted to replicate the GPWS escape
maneuver, particularly because wreckage examinations and FDR data
indicated that the speedbrakes were not retracted during the escape
maneuver. Because the B-757 flight simulators could not be back driven
during the tests, it could not be determined with precision whether
the airplane would have missed the mountain/tree tops if the
speedbrakes had been retracted during the escape attempt.
Organizational and Management Information
AA began operating its Latin American routes in July 1991,
and the MIA crew base opened at that time. At the time of the
accident, the MIA base was third in terms of the number of pilots,
behind DFW and Chicago-O'Hare International Airport (ORD). The
accident flightcrew members were based at MIA. On AA's Latin American
and Caribbean routs, 98.4 percent of the flightcrews were based at MIA.
The MIA base was overseen by a base manager who was a
B-757/767 captain in their South American division. He had been a line
pilot until approximately one year before the accident. AA's Latin
American operations and domestic operations from MIA were each
overseen by their own chief pilot.
Pilots based at MIA reported to the base manager. He was supervised by
the Assistant Vice President, Line Operations., who reported to the
Vice President, Flight Operations. He was supervised by the Executive
Vice President, Operations, who reported to the President of AA. The
President was responsible to the Chief Executive Officer of the
Additional lnformation
1.18.1 Air Traffic Control
Upon entering Colombian airspace on December 20, 1995, AA965
was under the control of the Barranquilla Center, and then Bogota
Center. Upon exiting the limits of the Bogota Center airspace, the
airplane entered the airspace controlled by Cali Approach.
At the time of the accident, the Cali approach
control facility was located in the control tower at SKCL. The
approach controller was located in a small cab 8 to 10 feet from the
tower controller. Flight progress strips were used to keep track of
aircraft that were inbound or outbound from the airport, or traversing
the Cali airspace. Radar coverage and radar services were not
available.
Colombian controllers operate under rules promulgated by the
Aeronautica Civil Communications. Pilots are governed by Annex 10 to
the Convention on International Civil Aviation, "Aeronautical
Telecommunications."
The annex establishes the rules under which
pilots and controllers, who are not conversant in each other' s native
language, can communicate.
Section 1.2 of Annex 10 states:
The primary means for exchanging information in air-ground
communications is the language of the ground stations, which will in
most cases be the national language of the State responsible for the
Paragraph 5.2.1.1 2 recommends, that where English is not the language
of the ground station the English language should be available on
request, thereby, the recommendations of the Annex indicate that the
English language will be available as a universal medium for
radiotelephone communications.
Section 1.4 of the Annex adds:
That means of assuring safety, however, can hardly be
satisfactory in practice. It is always possible that an emergency may
require communication with a ground station not foreseen in the
original planning, and that the handicapping or prevention of such
emergency communications by the lack of a language common to the
flightcrew and the ground station could lead to an accident.
In the Latin American Pilot Reference Guide that AA provided
to its Latin American division pilots, the following guidance was
Because the controller may not understand any comments that
are unexpected, out of sequence, or not in the ICAO format, you
should use only ICAO accepted radio-telephony terminology.
Colombian rules included the following:
If a clearance given by the air traffic control center is not
satisfactory to the pilot of the aircraft, the pilot can request an
amended clearance, and if possible, he will receive an amended
clearance.
1.18.2 Cali Air Traffic Controller
The air traffic controller, who was on duty at the time of the
accident, in his first interview indicated to investigators that there
were no language difficulties in the communications between himself
and the accident flightcrew.
However, in a second interview, when
asked a specific question regarding his opinion about the effects the
difference in native languages between the accident flightcrew and
approach control may have had, he stated that he would have asked the
pilots of AA965 more detailed questions regarding the routing and the
approach if the pilots had spoken Spanish. He stated that he believed
that his comprehension of the pilot's transmission was satisfactory
and that the pilot also understood him.
The controller said that, in
a non-radar environment, it was unusual for a pilot to request to fly
from his or her present position to the arrival transition. The air
traffic controller also stated that the request from the flight to fly
direct to the Tulua VOR, when the flight was 38 miles north of Cali,
made no sense to him. He said that his fluency in non-aviation English
was limited and he could not ask them to elaborate on the
request. Rather, he restated the clearance and requested their
relative to the Cali VOR. He believed that the pilot's response, that
AA965 was 37 miles from Cali, suggested that perhaps the pilot had
forgotten to report passing the Tulua VOR.
The controller further stated that had the pilots been
Spanish-speaking, he would have told them that their request made
little sense, and that it was illogical and incongruent. He said that
because of limitations in his command of English he was unable to
convey these thoughts to the crew.
1.18.3 FAA Surveillance
At the time of the accident, FAA oversight of AA's operations into
Latin America was the carried out by its Flight Standards District
Office (FSDO) No. 19, based at MIA. The FAA office responsible for
overall surveillance of AA was based near the airline's headquarters
in at DFW. FSDO 19 was the largest FSDO in the United States,
responsible for the oversight of 11 carriers operating under 14 Code
of Federal Regulations (CFR) Part 121, 51 carriers under Part 135, 12
flight schools operating under Part 141, 233 repair stations operating
under Part 145, as well as several other certificates. FSDO 23, also
based at MIA was responsible for surveillance of Part 129 foreign
carriers operating into MIA. Under a memorandum of understanding (MOU)
with FSDO-19, FSDO-23 accomplished some of the surveillance of
U.S. carriers operating into Latin America. FSDO 19 was responsible
for performing geographic surveillance of AA surveillance as well as
surveillance of United Airlines and Continental Airlines operations
into Latin America and the Caribbean. AA management personnel
described the FAA presence at MIA as positive and cooperative.
During post accident interviews, FAA personnel indicated that AA
conducted about 1,870 of the 7,200 weekly operations at MIA, and that
enroute surveillance of operations into South America were often
conducted by airworthiness inspectors who were already traveling to
Latin America to perform facility inspections. Airworthiness
inspectors would plan and conduct enroute inspections on flights to
South America, inspect the facility at the destination, and conduct
enroute inspections on the return trip. Inspections were planned in
this manner to reduce the FAA expenses associated with overseas
travel. During interviews, FAA personnel verified that operations
inspectors, who perform cockpit enroute checks are given different FAA
training than airworthiness inspectors.
Airworthiness inspectors
specialize in maintenance matters and are not qualified flightcrew
operational evaluators.
International Civil Aviation Organization (ICAO) document no. 8335,
Chapter 9, part 9.4.1 states:
Ideally a CAA inspector should be at least as qualified as the
personnel to be inspected or supervised. To carry out in-flight
inspections, a CAA inspector should not only be qualified in the type
of aircraft used but also possess appropriate route experience.
Part 9.6.33 states:
The following guidelines are suggested as minimum
requirements with respect to the frequency of conducting the various
inspections.
TypeFrequency
En-route inspectionquarterly
Three operations inspectors at FSDO-19 performed 1,807 flight
checks, including simulator, oral or actual airplane checks, out of
3,400 requests.
1.18.4 American Airlines Training in Latin American Operations
AA provided additional ground school instruction to all flightcrew
members who were to begin operations into Latin America. This followed
a 2-day ground school for all pilots who were to begin flying
international routes. In the Latin America training, the airline also
distributed to students a Jeppesen-sized reference guide devoted
exclusively to the hazards and demands of flying into Latin
America. Pilots also participated annually AA provided CRM training,
exclusive to Latin American flight operations. The training and
reference guide were not required by Federal Aviation Regulations
The following were among the title of topics addressed in both the
reference guide and initial ground school training:
Warning! Arrivals May be Hazardous
They'll [ATC] Forget About You
Know Where You Are!
When "Knowing Where You Are" is Critical
Howto Determine Terrain Altitude
In addition, the introduction to the reference guide included the
following guidance:
Flights into Latin America can be more challenging and far more
dangerous than domestic flying or the highly structured North
Atlantic/European operation. Some Latin American destinations have
multiple hazards to air operations, and ATC facilities may provide
little assistance in avoiding them.
Enroute and terminal radar coverage may be limited or non-existent.
Mountains, larger and more extensive than anything you've
probably ever seen, will loom up around you during descent and
approach, and during departure. Communications, navigation, weather
problems, and an Air Traffic Control philosophy peculiar to Latin
America may conspire with disastrous consequences.
There are many hazards in this environment, but the greatest danger is
pilot complacency. From 1979 through 1989, 44 major accidents
involving large commercial aircraft occurred in South America. Of
these 44 accidents, 34 were attributable to pilot error, or were
pilot-preventable with proper situational awareness (emphasis in
original).
Speedbrake System Description for the B-757
The speedbrake system in the B-757 consists of overwing control
surfaces that extend and retract at the command of the pilot through
the aft and forward movement of the speedbrake control lever located
in the top left side of the center control stand. In flight operation
of the speedbrake system is manual.
Automatic extension and
retraction are restricted to the landing phase and is activated upon
main wheel touchdown and forward movement of the power levers
respectively. Due to the limited aerodynamic effect of the
speedbrakes, flightcrews may become unaware that they are in the
extended mode. Annunciation of speedbrake deployment only becomes
activated in landing configuration and / or below 800 feet. (see
appendix D, Aileron and Spoiler Controls)
1.18.6GPWS Escape Maneuvers
The Ground Proximity Warning Escape Maneuver procedure was contained
in American Airlines B-757 Flight Operations Manual under the section
entitled, "Instruments." The procedure addressed the flightcrew
actions that must be carried out in order to attain maximum climb
performance of the airplane in order to overcome the obstacles ahead
of its flight path. These pilot actions include the dlsengagement of
autopilot and autothrottle system as well as selecting maximum power
and attaining best angle of climb.
2. ANALYSIS
There was no evidence of failures or malfunctions in the airplane, its
components, or its systems. Weather was not a factor in this
accident. Both crewmembers were properly qualified and certificated to
operate the airplane on this flight. The specific details of the
training history of the accident flightcrew was not available to the
accident investigation team, because of the AA policy of maintaining
training records which indicate only pass/fail on evaluations. No
evidence was found that either crewmember was experiencing a
behavioral or physiological impairment at the time that could have
caused or contributed to of the accident.
The evidence indicates that AA965 continued on the appropriate flight
path until it entered the Cali Approach airspace. After contacting the
Cali approach controller, the flightcrew accepted the controller's
offer to land on runway 19 at SKCL, rather than runway 01 per the
flight planned route. After receiving clearances to descend, lastly to
5,000 feet msl, neither flighterew member made an attempt to terminate
the descent, despite the airplane's deviation from the published
approach course, in a valley between two mountain ridges. After the
flightcrew recognized that the airplane had deviated from the
prescribed inbound course, as the first offieer stated less than 1
minute prior to impact, they attempted to turn back to the "extended
centerline" of the runway, which as the eaptain then stated, "...is
Rozo." The accident occurred following the turn back to the right from
a track to the east of the prescribed course and an attempt to fly in
a southwesterly heading to directly intercept the extended runway
centerline.
The investigation examined flightcrew actions to determine how a
properly trained and qualified crew would allow the airplane to
proceed off course, and continue the descent into an area of
mountainous terrain. In addition, the investigation examined the
actions of the Cali approach controller to determine what role, if
any, his actions may have had upon the accident. The quality of the
FAA surveillance of the AA South American operation was examined. The
investigation also assessed survivability issues to determine the
extent to which the number of the injuries and fatalities could have
been reduced, and the design of the speedbrake, and AA's procedures
and training in retracting speedbrakes during GPWS escape maneuvers..
The Decision to Accept Runway 19
The evidence indicates that the captain and first officer committed a
series of operational errors that led to the accident. The errors,
which individually were not causal, interacted in a way that caused
the accident. The CVR contained the final approximately 30 minutes of
cockpit voice recording, but did not contain details of an approach
briefing into Cali, and investigators were unable to determine whether
or how detailed a flightcrew approach briefing took place before the
beginning of recorded information. However, investigators were able to
identify a series of errors that initiated with the flightcrew's
acceptance of the controller's offer to land on runway 19 rather than
the filed approach to runway 01. This expectation was based on the
experience of AA pilots operating into Cali, where almost all landings
had been on runway 01, and AA's operations office at SKCL had radioed
the accident flightcrew about 5 minutes prior to the controller's
offer information regarding the active runway. Also, FMC
reconstruction found that the ILS approach to runway 01 had been
entered into the airplane's FMS.
The CVR indicates that the decision to accept the offer to
land on runway 19 was made jointly by the captain and first officer in
a 4-second exchange that began at 2136:38. The captain asked: "would
you like to shoot the one nine straight in?" The first officer
responded, "Yeah, we'll have to scramble to get down.
We can do it."
This interchange followed an earlier discussion in which the captain
indicated to the first officer his desire to hurry the arrival into
Cali, following the delay on departure from MIA, in an apparent
attempt to minimize the effect of the delay on the flight attendants'
rest requirements. For example, at 2126:01, he asked the first officer
to "keep the speed up in the descent."
As a result of the decision to accept a straight in approach to runway
19, the flightcrew needed to accomplish the following actions
expeditiously:
Locate, remove from its binder, and prominently position
the chart for the approach to runway 19
Review the approach chart for relevant information such
as radio frequencies, headings, altitudes, distances, and missed
procedures
Select and enter data from the airplane's flight
management system (FMS) computers regarding the new approach
Compare information on the VOR DME Runway 19 approach chart
with approach information displayed from FMS data
Verify that selected radio frequencies, airplane headings, and FMS-
entered data were correct
Recalculate airspeeds, altitudes, configurations and other airplane
control factors for selected points on the approach
Hasten the descent of the airplane because of the shorter distance
available to the end of new runway.
Monitor the course and descent of the airplane, while maintaining
communications with air traffi1c control (ATC)
The evidence of the hurried nature of the tasks performed and the inadequate
review of critical information between the time of the flightcrew's
acceptance of the offer to land on runway 19 and the flight's crossing
the initial approach fix, ULQ, indicates that insufficient time was
available to fully or effectively carry out these
actions. Consequently, several necessary steps were performed
improperly or not at all and the flightcrew failed to recognize that
the airplane was heading towards terrain, until just before
impact. Therefore, Aeronautica Civil believes that flightcrew actions
caused the accident.
Researchers studying decision making in dynamic situations [22] have suggested
that experienced persons can quickly make decisions based on cues that
they match with those from previous experiences encountered in similar
situations.
A referenced text refers to this characteristic as
Recognition Primed Decision Making, in which a decision maker's rapid
assessment of the situation is almost immediately followed by the
selection of an outcome. It states:
Our research has shown that recognitional decision making is
more likely when the decision maker is experienced, when time
pressure is greater, and when conditions are less stable. [23]
It is likely therefore that when previously faced with similar
situations, such as the opportunity to execute an approach that was
closer to the airplane's
----------------
[22] Klein, G., (1993), Naturalistic Decision Making: Implications for
Design. Wright-Patterson Air Force Base, Ohio: Crew System Ergonomics
Information Analysis Center.
[23] Klein, G., (1993), A recognition primed decision (RPD) model of
rapid decision making. In Klein, G. A., Orasanu, J., Calderwood, R.,
and Zsambok, C. E., (Eds.), Decision Making in Action: Models and
Methods. Norwood, New Jersey, Ablex, p. 146.
position than the approach anticipated, the pilots of AA965, each of
whom had acquired years of experience as air transport pilots,
accepted the offers and landed without incident.
However, recognition primed decision making can present risks to the
decision maker if the initial assessment of the situation is
incorrect, or if the situation changes sufficiently after the decision
has been made but the initial decision is not reconsidered. In this
accident, the latter scenario appears t there is
no evidence that either flightcrew member reconsidered the initial
decision to accept the offer to land on runway 19 and all subsequent
actions were directed to completing the steps necessary to
successfully land.
The evidence suggests that either of two reasons could account for the
flightcrew's persistence in attempting to land rather than
discontinuing the approach.
These include the failure to adequately
consider the time required to perform the steps needed to execute the
approach and the reluctance of decision makers in general to alter a
decision once it has been made.
The CVR transcript indicates that the captain, at 2137:10, gave the
only consideration either flightcrew member expressed in reference to
the time available, after accepting the offer to land on runway 19,
when he asked the first officer, in response to an ATC clearance,
"Yeah he did [say the Rozo 1 arrival].
We have time to pull that
[approach chart] out?" There is no response to this question, but the
CVR records the sound of "rustling pages," likely the approach
chart. Despite this comment, there is no evidence that either pilot
acknowledged that little time was available to perform the preliminary
tasks such as verifying their position relative to the navaids that
formed the basis for the approach or to execute the approach.
Once they began to prepare for the approach to runway 19, there is no
evidence that the flightcrew revisited the decision, despite
increasing evidence that should have discontinued the approach. This
evidence, supported by recovered FMC non volatile memory, includes the
following:
Inability to adequately review and brief the approach
Inability to adhere to requirement to obtain oral approval from the
other pilot before executing a flight path change through the FMS
Difficulty in locating the VLQ and Rozo fixes that were critical to
conducting the approach.
Turning left to fly for over one minute a heading that was
approximately a right angle from the published inbound course, while
continuing the descent to Cali
By not reconsidering that initial decision, the flightcrew acted
consistently with the findings of human factors research on decision
making that found that decision makers are reluctant to alter a
decision after it has been made.
For example [24]:
Operators tend to seek (and therefore find) information that confirms
the chosen hypothesis and to avoid information or tests whose outcome
... could disconfirm it. This bias produces a sort of "cognitive tunnel
vision" in which operators fail to encode or process information that
is contradictory to or inconsistent with the initially formulated
hypothesis. Such tunneling seems to be enhanced particularly under
conditions of high stress and workload.
Thus, in addition to simply being too busy to recognize that they
could not properly execute the approach, once the decision to land on
runway 19 had been made, the course of action taken was to continue
the approach, rather to consider discontinuing it.
Situational Awareness
Once they made the decision to accept the offer to land on runway 19,
the flightcrew displayed poor situation awareness, with regard to such
critical factors as the following:
Location of navaids and fixes
Proximity of terrain
Flight Path
The flightcrew's situation awareness was further compromised by a lack
of information regarding the rules which governed the logic and
priorities of the navigation data base in the FMS.
----------------
[24] Wickens, C. D., (1984), Engineering Psychology and Human
Performance. Columbus, Ohio: Charles E. Merrill, p. 97.
Situational awareness has been defined [25] as the:
...perception of the elements in the environment within a volume
of time and space, the comprehension of their meaning, and the
projection of their status in the near future.
To airline pilots, situational awareness refers to a flightcrew's
understanding of the status and flightpath of the aircraft, and the
accuracy of their prediction about i}