Large transport air carrier aircraft deviated from assigned SID track due to a computer program erro...

Attributes
ACN	245080
Time
Date	199306
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ccc airport : bdl
State Reference	NY
Altitude	msl bound lower : 10000 msl bound upper : 10000
Environment
Flight Conditions	Mixed
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure other departure sid : sid enroute airway : n90
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 68 flight time total : 19000 flight time type : 150
ASRS Report	245080
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other spatial deviation
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

FMC loaded with coastal 1 departure out of bdl with sherl transition. All points for SID were checked in FMC prior to departure and those points matched the SID. ATC cleared us direct to hfd and then on course. After hfd the FMC directed a turn towards sherl, bypassing thumb intersection and following points on the SID. ATC picked up that we turned to a southwest heading and gave us a vector back on course. ATC advised us that another large transport, same flight the night before, and 2 other flts (some flight number, dates unknown) had done the same thing. I checked with maintenance and they said the night before flight was the same aircraft (unable to determine the other 2 flts). Wrote up on arrival phl.

Original NASA ASRS Text

Title: LGT ACR ACFT DEVIATED FROM ASSIGNED SID TRACK DUE TO A COMPUTER PROGRAM ERROR IN THE ACFT FMC.

Narrative: FMC LOADED WITH COASTAL 1 DEP OUT OF BDL WITH SHERL TRANSITION. ALL POINTS FOR SID WERE CHKED IN FMC PRIOR TO DEP AND THOSE POINTS MATCHED THE SID. ATC CLRED US DIRECT TO HFD AND THEN ON COURSE. AFTER HFD THE FMC DIRECTED A TURN TOWARDS SHERL, BYPASSING THUMB INTXN AND FOLLOWING POINTS ON THE SID. ATC PICKED UP THAT WE TURNED TO A SW HDG AND GAVE US A VECTOR BACK ON COURSE. ATC ADVISED US THAT ANOTHER LGT, SAME FLT THE NIGHT BEFORE, AND 2 OTHER FLTS (SOME FLT NUMBER, DATES UNKNOWN) HAD DONE THE SAME THING. I CHKED WITH MAINT AND THEY SAID THE NIGHT BEFORE FLT WAS THE SAME ACFT (UNABLE TO DETERMINE THE OTHER 2 FLTS). WROTE UP ON ARR PHL.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Large transport air carrier aircraft deviated from assigned SID track due to a computer program error in the aircraft FMC.