Air carrier widebody transport heading deviation from departure vector.

Attributes
ACN	105914
Time
Date	198903
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : aus
State Reference	TX
Altitude	msl bound lower : 700 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : aus tower : stl
Operator	common carrier : air carrier
Make Model Name	Widebody Transport
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude climbout : takeoff ground other : taxi
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 15000
ASRS Report	105914
Person 2
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : atp pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 6000 flight time type : 100
ASRS Report	106294
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Shortly after takeoff on runway 31L, we were vectored to 040 degrees (right turn). When the controller questioned our 040 degree heading, we confirmed, at which time he said we were more like 340 degrees (60 degrees off) and gave us a turn to 90 degrees. We went to the magnetic compass (whiskey) and agreed with his headings. Using our heading set knobs to correct the headings we were able to align them with the magnetic compass quickly and proceeded to dfw. The probability was that the compass systems had not synchronized with the INS reference within 60-80 degrees. I should have been picked up on the runway prior to takeoff, but was not due to a rolling takeoff. No excuse intended, but believe me it's subtle and happened quickly--hopefully never again. Supplemental information from acn 106294: we were able to align our heading systems and continue to destination. The INS did not correctly sync the heading system prior to departure. Error should have been noticed but was not.

Original NASA ASRS Text

Title: ACR WDB HEADING DEVIATION FROM DEP VECTOR.

Narrative: SHORTLY AFTER TKOF ON RWY 31L, WE WERE VECTORED TO 040 DEGS (RIGHT TURN). WHEN THE CTLR QUESTIONED OUR 040 DEG HDG, WE CONFIRMED, AT WHICH TIME HE SAID WE WERE MORE LIKE 340 DEGS (60 DEGS OFF) AND GAVE US A TURN TO 90 DEGS. WE WENT TO THE MAGNETIC COMPASS (WHISKEY) AND AGREED WITH HIS HDGS. USING OUR HDG SET KNOBS TO CORRECT THE HDGS WE WERE ABLE TO ALIGN THEM WITH THE MAGNETIC COMPASS QUICKLY AND PROCEEDED TO DFW. THE PROBABILITY WAS THAT THE COMPASS SYSTEMS HAD NOT SYNCHRONIZED WITH THE INS REF WITHIN 60-80 DEGS. I SHOULD HAVE BEEN PICKED UP ON THE RWY PRIOR TO TKOF, BUT WAS NOT DUE TO A ROLLING TKOF. NO EXCUSE INTENDED, BUT BELIEVE ME IT'S SUBTLE AND HAPPENED QUICKLY--HOPEFULLY NEVER AGAIN. SUPPLEMENTAL INFO FROM ACN 106294: WE WERE ABLE TO ALIGN OUR HDG SYSTEMS AND CONTINUE TO DEST. THE INS DID NOT CORRECTLY SYNC THE HDG SYS PRIOR TO DEP. ERROR SHOULD HAVE BEEN NOTICED BUT WAS NOT.

Data retrieved from NASA's ASRS site as of August 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.