Heading track deviation during SID departure procedure.

Attributes
ACN	309930
Time
Date	199507
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sea
State Reference	WA
Altitude	msl bound lower : 4000 msl bound upper : 4800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea
Operator	general aviation : corporate
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 91
Navigation In Use	Other Other
Flight Phase	climbout : initial climbout : takeoff climbout : intermediate altitude
Route In Use	departure other departure sid : sid enroute other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 90 flight time total : 10500 flight time type : 2500
ASRS Report	309930
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Copilot flying from left seat, captain (me) right seat as is company policy. I handed SID to PF for review then we briefed the departure. We were assigned runway 34L for takeoff with commuter on runway 34R. Tower released commuter then released us for takeoff, to keep the commuter in sight. No problem as we had him visually and on TCASII. The PF was flying FMS to the 1ST 'fix' which was 8 mi, 4000 ft or more. Altitude was no problem, we were above 4000 ft but PF started turn too soon. Both of us watching commuter, FMS commanded turn to heading 070 degrees as per the SID. I checked DME and saw 6.8 -- not 8.0 as called out on SID. We turned to heading early. Departure asked if we had been assigned SID. I replied yes. He reminded us we needed 4000 ft and 8 mi before the turn east. We were both aware of what was to be flown and I caught the early turn, reminded PF but we were then on the heading (070 degrees). Several contributing factors: FMS 'turned us early,' both pilots watching traffic on right. Next time call turn from right seat or use VOR/DME on left side navigation rather than FMS, tell departure of error (after the turn, the DME was 7.6 mi so I thought it unnecessary to tell departure), check and double-check all the time.

Original NASA ASRS Text

Title: HDG TRACK DEV DURING SID DEP PROC.

Narrative: COPLT FLYING FROM L SEAT, CAPT (ME) R SEAT AS IS COMPANY POLICY. I HANDED SID TO PF FOR REVIEW THEN WE BRIEFED THE DEP. WE WERE ASSIGNED RWY 34L FOR TKOF WITH COMMUTER ON RWY 34R. TWR RELEASED COMMUTER THEN RELEASED US FOR TKOF, TO KEEP THE COMMUTER IN SIGHT. NO PROB AS WE HAD HIM VISUALLY AND ON TCASII. THE PF WAS FLYING FMS TO THE 1ST 'FIX' WHICH WAS 8 MI, 4000 FT OR MORE. ALT WAS NO PROB, WE WERE ABOVE 4000 FT BUT PF STARTED TURN TOO SOON. BOTH OF US WATCHING COMMUTER, FMS COMMANDED TURN TO HDG 070 DEGS AS PER THE SID. I CHKED DME AND SAW 6.8 -- NOT 8.0 AS CALLED OUT ON SID. WE TURNED TO HDG EARLY. DEP ASKED IF WE HAD BEEN ASSIGNED SID. I REPLIED YES. HE REMINDED US WE NEEDED 4000 FT AND 8 MI BEFORE THE TURN E. WE WERE BOTH AWARE OF WHAT WAS TO BE FLOWN AND I CAUGHT THE EARLY TURN, REMINDED PF BUT WE WERE THEN ON THE HDG (070 DEGS). SEVERAL CONTRIBUTING FACTORS: FMS 'TURNED US EARLY,' BOTH PLTS WATCHING TFC ON R. NEXT TIME CALL TURN FROM R SEAT OR USE VOR/DME ON L SIDE NAV RATHER THAN FMS, TELL DEP OF ERROR (AFTER THE TURN, THE DME WAS 7.6 MI SO I THOUGHT IT UNNECESSARY TO TELL DEP), CHK AND DOUBLE-CHK ALL THE TIME.

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.