Medium large transport flight crew misinterprets departure clearance. Heading deviation.

Attributes
ACN	328940
Time
Date	199602
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : yul
State Reference	PQ
Altitude	msl bound lower : 2300 msl bound upper : 2300
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	tower : yul artcc : zob
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : initial climbout : takeoff
Route In Use	departure other departure sid : sid 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 : 120 flight time total : 13500 flight time type : 2300
ASRS Report	328940
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Assigned dorval 1 departure, runway 28. Assigned 315 degree heading by tower upon takeoff. To comply with noise abatement I thought we were supposed to fly runway heading to 3000 ft before turning. Immediately after takeoff I called departure control and stated we were flying runway heading to 3000 ft then turning to 315 degree heading. Departure control replied and told us to 'fly 315 degrees now.' we turned immediately and the flight proceeded normally. I apparently misinterpreted the noise procedure and should have asked for clarification from the tower before takeoff.

Original NASA ASRS Text

Title: MLG FLC MISINTERPRETS DEP CLRNC. HDG DEV.

Narrative: ASSIGNED DORVAL 1 DEP, RWY 28. ASSIGNED 315 DEG HDG BY TWR UPON TKOF. TO COMPLY WITH NOISE ABATEMENT I THOUGHT WE WERE SUPPOSED TO FLY RWY HDG TO 3000 FT BEFORE TURNING. IMMEDIATELY AFTER TKOF I CALLED DEP CTL AND STATED WE WERE FLYING RWY HDG TO 3000 FT THEN TURNING TO 315 DEG HDG. DEP CTL REPLIED AND TOLD US TO 'FLY 315 DEGS NOW.' WE TURNED IMMEDIATELY AND THE FLT PROCEEDED NORMALLY. I APPARENTLY MISINTERPRETED THE NOISE PROC AND SHOULD HAVE ASKED FOR CLARIFICATION FROM THE TWR BEFORE TKOF.

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.