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B762, vicinity Busan Korea, 2002 (CFIT HF)
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|On 15 April 2002, during daytime in poor visibility conditions, a Boeing 767-200 operated by Air China crashed during a circling approach, on Mt. Dotdae located 4.6 km north of runway 18R threshold at Busan/Gimhae International Airport at an elevation of 204m AMSL.|
|Event Type||CFIT, HF|
|Type of Flight||Public Transport (Passenger)|
|Origin||Beijing Capital International|
|ENR / APR|
|Location - Airport|
|Tag(s)|| Civil use of military airport|
Inadequate Airworthiness Procedures
Inadequate Aircraft Operator Procedures
Inadequate ATC Procedures
|Tag(s)|| Into terrain|
No Visual Reference
Lateral Navigation Error
Vertical navigation error
IFR flight plan
|Tag(s)|| Spatial Disorientation|
Procedural non compliance
|Safety Net Mitigations|
|Malfunction of Relevant Safety Net||No|
|GPWS||Available but ineffective|
|MSAW||Available but ineffective|
|Damage or injury||Yes|
|Aircraft damage||Hull loss|
|Fatalities||Most or all occupants|
|Causal Factor Group(s)|
|Group(s)|| Aircraft Operation|
Air Traffic Management
On 15 April 2002, during daytime in poor visibility conditions, a Boeing 767-200 operated by Air China crashed during a circling approach, on Mt. Dotdae located 4.6 km2.484 nm
15,091.864 ft north of runway 18R threshold at Busan/Gimhae International Airport at an elevation of 204 m669.291 ft AMSL.
This is an extract from the official report of the the accident published by the Korean Aviation - accident Investigation Board (KAIB):
Upon receiving the report that the crew had the runway in sight at 1.7 miles from the end of runway 36L, the approach controller instructed the aircraft to fly the circling approach to runway 18R, and then transferred the control of the flight to the tower. He stated that he verified the flight initiating the normal circling approach.
The testimony of the captain (who survived the crash) is enclosed in the accident Report and part of it includes:
[...]The base turn was started when twenty seconds past abeam the north end of runway 18R, with the ground visible, but without any point of reference. About two thirds of the base turn, the flight entered the clouds, and he saw a hill as the flight emerged from the clouds. Once the base turn was started, there were no words of advice from the first officer, with no comments on the altitude either, but only the callout, “Pull up! Pull up!” After entering the clouds, the captain intended to initiate a go around after rolling out on final to the direction of the runway. […]
According the Report the accident flight was equipped with ground proximity warning system (GPWS), which did not provide any alerts because it was operating outside its terrain warning envelope. The aircraft was configured for landing with gear down, flaps in landing configuration (25 degrees or more) and maximum closure rate of 1,800 fpm.
The Report further states:
The MSAW [Minimum Surface Altitude Warning] system at Gimhae airport was designed and produced to display only visual warning [in this case it is alerting the controller with flashing letters “LA” on the ground speed portion of the aircraft data tag], anytime an aircraft is flying below the MSAW activation altitude, thus unless the controllers had been continuously monitoring the radar scope or BRITE [radar scope designed to be used under bright conditions and installed in the Gimhae/Busan TWR] display, they would not have been able to recognize warnings in progress, and thereby to provide safety alerts in a timely manner. However, it is a common practice in many other installations at domestic or overseas airports, as well as an ICAO recommendation that the MSAW incorporates both acoustic and visual warning functions. Human factors considerations regarding controller vigilance during monitoring of radar scopes dictate that the acoustic warning function should be included to complement the visual warning, particularly to alert the controllers and their supervisors to an impending problem that might otherwise be overlooked.
The minimum safe altitude was set at “0” ft in the area near the airport with takeoffs and landing traffic centered around the antenna, in order to inhibit frequent activation of nuisance warnings.
The Report includes the following findings related to probable causes to the accident:
- The flight crew of flight 129 performed the circling approach, not being aware of the weather minima of wide-body aircraft (B767-200) for landing, and in the approach briefing, did not include the missed approach, etc., among the items specified in Air China’s operations and training manuals.
- The flight crew exercised poor crew resource management and lost situational awareness during the circling approach to runway 18R, which led them to fly outside of the circling approach area, delaying the base turn, contrary to the captain’s intention to make a timely base turn.
- The flight crew did not execute a missed approach when they lost sight of the runway during the circling approach to runway 18R, which led them to strike high terrain (mountain) near the airport.
- When the first officer advised the captain to execute a missed approach about 5 seconds before impact, the captain did not react, nor did the first officer initiate the missed approach himself.
The accident Report also includes the following findings as related to risk:
- The flight crew’s training for the circling approach was conducted with the simulator only for the Beijing Capital International Airport (Beijing airport hereinafter), and they had never been trained for the circling approach to Gimhae airport’s runway 18R.
- The crew resource management (CRM) training of Air China was insufficient for the three flight crew complement.
- Air China did not perform the improving action for Service Bulletin (SB) 767-34-0067(May 31, 1989), which was issued by the Boeing Company for the reinforcement of the GPWS functions.
- Air China provided one set of Jeppesen manuals to the flight crew, which the captain was using during the instrument approach, making it difficult for the other flight crewmembers to crosscheck the information in the manuals.
- Instrument approach chart used by the flight crew of flight 129 did not depict the high terrain north of the airport.
- During the circling approach, the flight crew of flight 129 did not use standard callouts defined by Air China.
- Flight 129 was flown between 150 and 160 kt on the downwind leg, which exceeded the maximum speed of 140 kt of Gimhae airport’s circling approach category “C,” and the width of the downwind leg was narrower than normal, for which corrective actions were inappropriate.
- The second officer, tasked with handling radio communications, did not reply correctly to controllers’ instructions a number of times, however, the captain and first officer did not correct the second officer’s inappropriate replies.
- When the tower controllers lost visual contact with the flight 129 aircraft on the downwind and base legs, they tried to find the flight 129 aircraft visually, however, they did not use the tower BRITE, which is an aid to complement visual observations.
- The flight crew did not reply appropriately to the local [tower] controller’s question when the controller asked them the possibility of landing, because the local controller did not have the flight 129 aircraft in sight after issuing the landing clearance.
- The approach controller felt that the flight 129 aircraft was flying on a longer pattern than normal, so he asked the local controllers via intercom, “Does it seem go around?” however, the local controllers stated that they did not hear this question.
- The local controller asked a question to the flight crew to confirm the position of the aircraft, however, the local controller did not issue any direct warning or advice based on his own subjective awareness of the situation.
- “The Korean Standard Air Traffic Control Procedures”and “Gimhae Base Local Procedures” did not specify radar monitoring of the aircraft on a circling approach by means of the BRITE and MSAW systems.
- The MSAW system installed in Gimhae tower at the time of the accident was designed only with the function of visual warning, which was not consistent with the ICAO recommendation to include an aural warning also. Thus, the low altitude (LA) warning would not have been noticed in a timely manner, unless the controller monitored the BRITE closely.
- The MSAW activation area was programmed in the vicinity north of the circling approach area of Gimhae airport, which was set to be higher than the altitude of the circling approach pattern, and the MSAW would be activated in the case of a normal base turn in close proximity to the MSAW activation area within the circling approach area due to its predictive warning function.
When the aircraft disappeared from radar, and radio communication was lost between the tower and the aircraft, the tower controllers did not notify the search and rescue department in a timely manner.
- The measuring equipment of runway visual range (RVR) of Gimhae airport’s runway (18R/36L) had been out of order for a considerable time period, thus it had not been operated appropriately for the purpose of category II runway-use.
The Report's recommendations, beginning on page 160, focus on the institutional and organisational issues (see Further Reading).
For further information see the full accident report published by KAIB.