B737-700 flight crew has a track and heading deviation during mountain five departure from sea.

Attributes
ACN	716014
Time
Date	200611
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sea.airport
State Reference	WA
Altitude	msl single value : 3000
Environment
Flight Conditions	IMC
Weather Elements	Windshear Rain
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : s46.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	climbout : initial
Route In Use	departure sid : mtn5
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 221 flight time type : 221
ASRS Report	716014
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 161
ASRS Report	716016
Events
Anomaly	non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance Chart Or Publication
Primary Problem	Flight Crew Human Performance

Narrative:

On the mountain 5 departure out of sea; we incorrectly briefed that the turn to 070 degrees should occur at 3000 ft; as opposed to 3000 ft and 5 DME. So; once we reached 3000 ft; we turned left to 070 degrees. Basically we wound up turning 2 mi too early. ATC asked if we were turning for WX in the area; and we said 'no.' he said he had no problem with what we did. We should have taken more time to read the text portion of the SID. If we had done that; we would not have made the error. Also; the sea mountain 5 departure could also highlight the 5 DME portion in the plan view.

Original NASA ASRS Text

Title: B737-700 FLT CREW HAS A TRACK AND HDG DEV DURING MOUNTAIN FIVE DEP FROM SEA.

Narrative: ON THE MOUNTAIN 5 DEP OUT OF SEA; WE INCORRECTLY BRIEFED THAT THE TURN TO 070 DEGS SHOULD OCCUR AT 3000 FT; AS OPPOSED TO 3000 FT AND 5 DME. SO; ONCE WE REACHED 3000 FT; WE TURNED L TO 070 DEGS. BASICALLY WE WOUND UP TURNING 2 MI TOO EARLY. ATC ASKED IF WE WERE TURNING FOR WX IN THE AREA; AND WE SAID 'NO.' HE SAID HE HAD NO PROB WITH WHAT WE DID. WE SHOULD HAVE TAKEN MORE TIME TO READ THE TEXT PORTION OF THE SID. IF WE HAD DONE THAT; WE WOULD NOT HAVE MADE THE ERROR. ALSO; THE SEA MOUNTAIN 5 DEP COULD ALSO HIGHLIGHT THE 5 DME PORTION IN THE PLAN VIEW.

Data retrieved from NASA's ASRS site as of January 2009 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.