Incident at GANDER INTL NL (CYQX) (Flight instrument failure, Conflict - loss of separation, Communication navigation surveillance/air traffic system)


2001-08-01: TSB Update August 1, 2001. A01A0089: The Luftansa Airlines Boeing 747-200, call-sign DLH422, was on a scheduled flight from Frankfurt Intl. Airport to Logan Intl. Airport. The aircraft was approaching 51N/50W at FL350 when a programming error within one of the two Inertial Navigation Systems (INS) commanded the autopilot to turn the aircraft east of original track. Gander ACC attempted to intervene and correct the problem but the effort had limited effect due to the aircraft position at the time, limit of radar coverage and communication range. Traffic affected was an Olympic Airlines Airbus 340 on a parallel track 60 NM south. Separation required was 60 NM; actual separation eroded to 40 NM. Other traffic affected was a Virgin Atlantic Airbus 340 at FL350 approximately 21 minutes behind the Lufthansa aircraft. Virgin Atlantic was cleared to FL360 to avoid the traffic. Separation required was 10 minutes; however, separation achieved was approximately 8 minutes. The Luftansa Flight Safety Department is conducting an investigation into flight crew cross check procedures while programming the INS systems.
2001-07-30: DLH422 B747 enroute Frankfurt to Bostn when approaching 51n/50w at FL350, DLH422 lost programming in his FMS system. Programming reverted to original state with coordinates 00/00. The aircraft turned left and headed in an easterly direction. The controller attempted to intervene to correct the problem but was limited because the aircraft was at the limit of radar and communications control. Traffic was OAL423 operating at FL350 on a track 60 miles south and parallel. Separation required was 60 miles, separation acheived was 40 miles. Traffic also was VIR27 operating at FL350 and 21 minutes behind DLH422. Separation required was 10 minutes. Separation acheived was approximatly 8 minutes. VIR27 had also been cleared to FL360 to avoid the traffic and reported level at 1454. Operating Irregularity occurred due to aircraft equipment failure. No Nav Canada involvement. TSB Case Closed with more to follow.


CADORS Number 2001A0462
Occurrence Type Incident
Reported By NAV CANADA
Occurred At 2001-07-29 - 14:40
Day or Night? Day-time
Fatalities 0
Aerodrome ID CYQX
Aerodrome Name GANDER INTL NL (CYQX)
Geographic Location Newfoundland and Labrador, Canada, North America, Atlantic Region, Gander Oceanic
TSB Occurrence Number A01A0089
TSB Class of Investigation Class 5
AOR Number 16734
Reported By NAV CANADA
Categories System/component failure or malfunction [non-powerplant],Airprox/TCAS alert/loss of separation/(near) midair collisions,ATM/CNS
Events Flight instrument failure,Conflict - loss of separation,Communication navigation surveillance/air traffic system

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