There is a lot of blame to go around here, not all of it apparent in the official accident report.
The Air China manual classified this Boeing 767 as Category C for straight in approaches and Category D for circling. The crew briefed and began the only available instrument approach: ILS 36L. When the runway was changed to 18R the controller asked the crew for their Approach Category and they responded "Charlie." During their maneuvering they were recorded at 160 knots, well above the Category C maximum speed.
If you really want to trace the causes of an aviation mishap, look at the corrective action taken as a result. The job here, after all, is to prevent recurrence. The circling minimums were based on U.S. TERPS which, back then, were much tighter than ICAO standards. Having to maneuver a Boeing 767 within 2.3 nm under Category D minimums is foolhardy. Doing so within 1.7 nm under Category C minimums, in this case, was fatal to most of the passengers on board.
The FAA acknowledged this in 2009, seven years later, by revising TERPS Circling Approach Area criteria. While most U.S. circling approaches are still, as of April 2013, based on the tighter criteria, charts designed after 2011 should be closer to the ICAO standard.
The approach plate in front of you is probably based on the smaller area. You as the pilot can improve your odds by upping your personal visibility minimums. Mine? Three miles gets me to the ICAO minimums and revised TERPS standards. What about your minimum ceiling to circle? We require a go around if outside of Stabilized Approach criteria at 1,000 feet when IMC. If your ceiling minimums are lower than 1,000 feet, you can't do this. We also require a go around if you are not stabilized below 500 feet on a visual or circling approach. If you are fully banked turning on final two miles from the runway, you can't do this.
Everything here is from the references shown below, with a few comments in an alternate color.
Figure: RKPK ILS/DME 36L, from Korea Aviation Accident Investigation Board Report, Figure 1-10.
Click photo for a larger image
[Korea AAR F0201, page 25]
The Boeing 767 is a Category Delta aircraft
Because this approach was designed using older TERPS criteria, as are most approaches in the United States, it had an unreasonably small circling approach area.
More about this: Circling Approach Area.
It is unclear why the first officer needed to manually fly the descent. He did not turn the aircraft using a standard rate and to the full heading needed to establish an adequate offset. He did not correct for the "overshooting" crosswind and by the time they were abeam the end of runway 18R, they only had 1.1 NM offset which would not be enough of a diameter for the airplane to complete a base turn to final.
Figure: Circling Approach Radar Track, from Korea Aviation Accident Investigation Board Report, Figure 1-7.
Click photo for a larger image
[Korea AAR F0201, page 17]
The approach was designed under older TERPS criteria with a 1.7 NM radius for Category C and 2.3 NM radius for Category D aircraft. The aircraft crashed at a point about 2.48 NM from the threshold of runway 18R. Had the approach been designed under ICAO rules, or under newer TERPS rules, the radius would have been much wider but so would the visibility required to fly the circling approach. All of that notwithstanding, the downwind was flown too close to the runway to make the turn even under optimal conditions.
[Korea AAR F0201, page 18]
Korea Aviation Accident Investigation Board Report, AAR F0201, Controlled Flight Into Terrain, Air China International Flight 129, B767-200ER, B2552, Mountain Dotdae, Gimhae, April 15, 2002
Copyright 2019. Code 7700 LLC. All Rights Reserved.