Flight crew of heavy transport departing sea interpreted clearance to mean turn now, rather than fol...

Attributes
ACN	121868
Time
Date	198909
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : sea
State Reference	WA
Altitude	msl bound lower : 2500 msl bound upper : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	departure other departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time total : 2150
ASRS Report	121868
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 18000 flight time type : 150
ASRS Report	121875
Events
Anomaly	non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other other
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

After reaching approximately 3 DME north of sea VOR, departure control issued a clearance, 'heavy transport on the mountain one departure, turn right heading 050.' to me, this meant the controller was saying, I acknowledge that you are on the mountain one departure but you are to turn now to 050 degree. It seemed like an amendment to our SID. (Normally 8 DME fix is where turn is initiated). I have flown out of seattle often and have not heard that terminology. It has always been to my recollection 'at the 8 DME fix, turn XXXX'. This change of terminology threw me off and further convinced me that our clearance was an amendment to the SID (mountain one departure). We turned immediately to 050 degree. The controller came back and said we were not supposed to turn yet and she gave us vectors to resume the SID. Sea departure controllers should standardize their terminology on the SID. I think 'spelling' out the fix at which a turn should be started would alleviate confusion.

Original NASA ASRS Text

Title: FLT CREW OF HVT DEPARTING SEA INTERPRETED CLRNC TO MEAN TURN NOW, RATHER THAN FOLLOW THE SID.

Narrative: AFTER REACHING APPROX 3 DME N OF SEA VOR, DEP CTL ISSUED A CLRNC, 'HVT ON THE MOUNTAIN ONE DEP, TURN RIGHT HDG 050.' TO ME, THIS MEANT THE CTLR WAS SAYING, I ACKNOWLEDGE THAT YOU ARE ON THE MOUNTAIN ONE DEP BUT YOU ARE TO TURN NOW TO 050 DEG. IT SEEMED LIKE AN AMENDMENT TO OUR SID. (NORMALLY 8 DME FIX IS WHERE TURN IS INITIATED). I HAVE FLOWN OUT OF SEATTLE OFTEN AND HAVE NOT HEARD THAT TERMINOLOGY. IT HAS ALWAYS BEEN TO MY RECOLLECTION 'AT THE 8 DME FIX, TURN XXXX'. THIS CHANGE OF TERMINOLOGY THREW ME OFF AND FURTHER CONVINCED ME THAT OUR CLRNC WAS AN AMENDMENT TO THE SID (MOUNTAIN ONE DEP). WE TURNED IMMEDIATELY TO 050 DEG. THE CTLR CAME BACK AND SAID WE WERE NOT SUPPOSED TO TURN YET AND SHE GAVE US VECTORS TO RESUME THE SID. SEA DEP CTLRS SHOULD STANDARDIZE THEIR TERMINOLOGY ON THE SID. I THINK 'SPELLING' OUT THE FIX AT WHICH A TURN SHOULD BE STARTED WOULD ALLEVIATE CONFUSION.

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.

Flight crew of heavy transport departing sea interpreted clearance to mean turn now, rather than follow the SID.