Tuesday, November 16, 2010

Crew fatigue cited in Delta Air Lines Boeing 767 taxiway landing at Atlanta

by B. N. Sullivan

A final report has been issued by the U.S. National Transportation Safety Board (NTSB) regarding its investigation of a 2009 incident in which a Delta Air Lines Boeing 767-332ER aircraft landed on a taxiway at Atlanta's Hartsfield-Jackson International Airport (ATL).  According to the report, crew fatigue was a major cause of the incident.

At the time of the incident, on October 19, 2009, the aircraft (registration N185DN) was arriving at Atlanta.  The aircraft was operating as Delta Flight 60, a scheduled passenger service from Rio de Janeiro (GIG) to ATL.  The NTSB report summary gives this account of what happened:
During the flight one of the three required flight deck crew members became ill and was considered to be incapacitated.  The remaining two crew members conducted the entire night flight without the benefit of a customary break period.  Throughout the flight the crew made comments indicating that they were fatigued and identified fatigue as their highest threat for the approach, but did not discuss strategies to mitigate the consequences of fatigue.  At the time of the incident, the crew had been on duty for about 12 hours and the captain had been awake for over 22 hours, while the first officer had been awake for at least 14 hours.

During the descent and approach, the flight crew was assigned a number of runway changes; the last of which occurred near the final approach fix for runway 27L While the flight was on final approach, the crew was offered and accepted a clearance to sidestep to runway 27R for landing.  Although the flight crew had previously conducted an approach briefing for two different runways, they had not briefed the approach for runway 27R and were not aware that the approach light system and the instrument landing system (ILS) were not available to aid in identifying that runway.  When the crew accepted the sidestep to runway 27R, the captain, who was the flying pilot, saw the precision approach path indicator and lined the airplane up on what he said were the brightest set of lights he could see.  During the final approach, the first officer was preoccupied with attempting to tune and identify the ILS frequency for runway 27R.  Just prior to the airplane touching down, the captain realized they were landing on a taxiway.  The airplane landed on taxiway M, 200 feet north of, and parallel to, runway 27R.

Postincident flight evaluations of the airport lighting indicated that there were a number of visual cues that could have misguided the captain to align with taxiway M instead of runway 27R while on final approach.  These cues included numerous taxiways signs along the sides of taxiway M which, from the air, appeared to be white and could be perceived as runway edge lights.  In addition, the blue light emitting diode (LED) lights used on the eastern end of taxiway M were perceived to be brighter than the adjacent incandescent lights on the airfield and the alternating yellow and green lights in the ILS critical area provided the appearance of a runway centerline.  The postincident flight evaluations indicated that when the approach lights or the ILS for runway 27R were available and used, it was clearly evident when the airplane was not aligned with the runway.
The NTSB determined the probable cause of this incident to be, "The flight crew’s failure to identify the correct landing surface due to fatigue."

Contributing causes were:
  • the flight crew’s decision to accept a late runway change,
  • the unavailability of the approach light system and the instrument landing system for the runway of intended landing,
  • the combination of numerous taxiway signs and intermixing of light technologies on the taxiway.
No one was injured in the incident.

Here are the links to the NTSB's final report:
RELATED:  NTSB investigating Delta Air Lines Boeing 767 taxiway landing at Atlanta - AircrewBuzz.com, Oct 21, 2009