Missed turn in SID account GPWS sounding and trying to silence.

Attributes
ACN	257178
Time
Date	199311
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sea
State Reference	WA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 21000 flight time type : 50
ASRS Report	257178
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 8700 flight time type : 1200
ASRS Report	257177
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : anomaly accepted other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

We were on the mountain 3 SID from sea-tac, at approximately 300-400 ft. Our GPWS began giving us a terrain warning and it continued through 10000 ft. We could not inhibit the warning. The aural warning was so loud it made ATC transactions difficult to a point we had to ask departure control to repeat a couple of times. We understood departure wanted us to stay on the 338 degree radial. Through the confusion we did not turn to the 070 degree heading, as per the SID. At approximately 13 NM, ATC advised us of our error and turned us to 070 degrees. We were advised no conflict or problem occurred. Contributing factor -- noise level of the GPWS and distraction level of GPWS. Recommendation -- turn down the volume.

Original NASA ASRS Text

Title: MISSED TURN IN SID ACCOUNT GPWS SOUNDING AND TRYING TO SILENCE.

Narrative: WE WERE ON THE MOUNTAIN 3 SID FROM SEA-TAC, AT APPROX 300-400 FT. OUR GPWS BEGAN GIVING US A TERRAIN WARNING AND IT CONTINUED THROUGH 10000 FT. WE COULD NOT INHIBIT THE WARNING. THE AURAL WARNING WAS SO LOUD IT MADE ATC TRANSACTIONS DIFFICULT TO A POINT WE HAD TO ASK DEP CTL TO REPEAT A COUPLE OF TIMES. WE UNDERSTOOD DEP WANTED US TO STAY ON THE 338 DEG RADIAL. THROUGH THE CONFUSION WE DID NOT TURN TO THE 070 DEG HDG, AS PER THE SID. AT APPROX 13 NM, ATC ADVISED US OF OUR ERROR AND TURNED US TO 070 DEGS. WE WERE ADVISED NO CONFLICT OR PROB OCCURRED. CONTRIBUTING FACTOR -- NOISE LEVEL OF THE GPWS AND DISTR LEVEL OF GPWS. RECOMMENDATION -- TURN DOWN THE VOLUME.

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.