Korean Air Cargo Flight 8509

Coordinates: 51°51′23″N 0°12′59″E / 51.85639°N 0.21639°E / 51.85639; 0.21639
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Korean Air Cargo Flight 8509
A large cargo aircraft in the colours of Korean Air Cargo
HL7451, the 747 involved in the accident, in 1992.
Accident
Date22 December 1999
SummaryCrashed after take off due to pilot error caused by instrument failure compounded by poor CRM
SiteGreat Hallingbury, England, United Kingdom
51°51′23″N 0°12′59″E / 51.85639°N 0.21639°E / 51.85639; 0.21639[1]
Aircraft
Aircraft typeBoeing 747-2B5F
OperatorKorean Air Cargo
IATA flight No.KE8509
ICAO flight No.KAL8509
Call signKOREAN AIR 8509
RegistrationHL7451
Flight originGimpo International Airport, Seoul, South Korea
1st stopoverTashkent International Airport, Tashkent, Uzbekistan
2nd stopoverLondon Stansted Airport, England, United Kingdom
DestinationMilan Malpensa Airport, Milan, Italy
Occupants4
Crew4
Fatalities4
Survivors0

Korean Air Cargo Flight 8509 was a

Boeing 747-2B5F, registered HL7451 bound for Milan Malpensa Airport, that crashed due to instrument malfunction and pilot error on 22 December 1999 shortly after take-off from London Stansted Airport where the final leg of its route from South Korea to Italy had begun. The aircraft crashed into Hatfield Forest near the village of Great Hallingbury, close to, but clear of, some houses. All four crew members on board were killed.[2][3]

The aircraft

The aircraft involved was a 19-year-old

Boeing 747-200F freighter registered HL7451. First flown on 4 April 1980, the aircraft had completed 15,451 flights with a total flight time of 83,011 hours before its fatal flight.[2][4][5]

INU failure and failed repair

Following the plane's departure from

inertial navigation units (INUs) had partially failed, providing erroneous roll data to the captain's attitude director indicator (ADI or artificial horizon). The first officer's ADI and a backup ADI were correct, a comparator alarm called attention to the discrepancy, and in daylight, the erroneous indication was easily identified. The ADI's input selector was switched to the other INU and the correct indications returned.[2]

At Stansted, the engineers who attempted to repair the ADI did not have the correct Fault Isolation Manual available and did not repair or replace the faulty number 1 INU. One of them identified and repaired a damaged connecting plug on the ADI. When the ADI responded correctly to its "Test" button, they believed the fault had been corrected, although this button only tested the ADI and not the INU. The ADI's input selector was left in the normal position.[2]

Flight crew

The flight crew consisted of:

  • 57-year-old Captain Park Duk-kyu (
    M-R
    : Pak Tŭkkyu)
  • 33-year-old First Officer Yoon Ki-sik (
    M-R
    : Yun Kishik)
  • 38-year-old Flight Engineer Park Hoon-kyu (
    M-R
    : Pak Hun'gyu)
  • 45-year-old maintenance mechanic Kim Il-suk (
    M-R: Kim Ilsŏk).[6][7]

The captain was a former colonel and pilot in the Republic of Korea Air Force and a highly experienced airman,[8] with a total of 13,490 flying hours – 8,495 of which were accumulated flying Boeing 747s. The first officer, in contrast, was relatively inexperienced with just 195 hours of flying experience on the 747 and a total of 1,406 flight hours. The flight engineer, like the captain, had a lot of experience flying 747s – 4,511 out of his 8,301 total flight hours were accrued in them. The maintenance mechanic had been involved with the failed INU repair.[8]

Flight

Attitude reference data at the moment of impact of HL-7451. Note the captain's (left side) ADI shows the aircraft near wings-level and nearly 40 degrees nose-down, while the first officer's (right) ADI shown the aircraft in a steep left bank of nearly 90 degrees and nearly 40 degrees nose down. These indications were reconstructed using the last information recovered from the flight data recorder. The centre instrument, the "standby horizon," was heavily damaged in the impact, and only the front part of it was recovered a year later. Its near 90 degree bank angle agrees with the first officer's ADI, and smudge marks suggest the vertical reference was forcibly moved against the instrument, which might account for its apparent pitch discrepancy with the other two instruments.[1][2]

It was dark when the plane took off from

bank attitude.[2] The aircraft exploded on impact.[8]

Aftermath

After the investigation, the United Kingdom's Air Accidents Investigation Branch (AAIB) issued recommendations to Korean Air to revise its training program and company culture, to promote a more free atmosphere between the captain and the first officer.[8] The first recommendation of the AAIB's final accident report was that:

Korean Air continue to update their training and Flight Quality Assurance programmes, to accommodate Crew Resource Management evolution and industry developments, to address issues specific to their operational environment and ensure adaptation of imported training material to accommodate the Korean culture.[2][1]

In popular culture

A March 2012 episode of Mayday also called Air Crash Investigation in the U.K. and the rest of the world (Season 11 Episode 7) titled "Bad Attitude" or "Stansted Crash" investigates this accident.[8]

See also

References

External links