Computer-Related Incidents with Commercial Aircraft

The Korean Air Lines B747 CFIT Accident in Guam

6 August 1997

Synopsis Approaching Won Pat International Airport on a Localiser-only ILS approach to Runway 6 Left at night, Korean Air Lines Flight 801 impacted Nimitz Hill at 658ft just a few hundred yards from the VORTAC antenna, whose DME KE801 should have been using, and nearly 800ft below the minimum altitude at that point on the approach.

While initially the accident seemed to have little to do with automated systems, it turned out that the Minimum Safe Altitude Warning (MSAW) System used by the Agana tower controllers and installed at nearby Andersen Air Force Base some 10 nautical miles beyond the departure end of Rwy 6L had unbeknowst to controllers not been operational, due to software errors in a new software installation.

Furthermore, when the descent profile and CVR transcript became available, questions were raised about the crew's "resource management" that are also pertinent to dealing with more recent automation and procedures.

These two points were sufficient for us to include two documents on this accident in the compendium.

The first, The Crash of Flight KE801, a Boeing B747-300, Guam, Wednesday 6 August, 1997: What We Know So Far, puts together publically-available information from the weeks after the crash; analyses this information with a view to determining what facts were available; and compiles and comments on the often confusing, unreliable and occasionally frankly false information distributed by news organisations as well as other organisations involved in the crash. Part of the purpose of this commentary is to establish a `social context' for the aftermath of a crash, as the author attempted also to do for the case of Aeroperu Flight 603 in 1996.

We shall include the full set of documents provided by the US National Transportation Safety Board for the Public Hearings on the accident in March 1998, which is a local copy of the original Public Hearings documents on the NTSB Web site.