A320 crew had track deviation in S46 class east airspace.

Attributes
ACN	475304
Time
Date	200006
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sea.airport
State Reference	WA
Altitude	msl bound lower : 11000 msl bound upper : 14000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : s46.tracon
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	climbout : vacating altitude
Route In Use	departure sid : bluit 3
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 1200
ASRS Report	475304
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter : weather non adherence : published procedure non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : separated traffic controller : issued alert
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Departed runway 16L on bluit 3 departure. Requested left turn off departure due to WX (shoer) south of airport. Cleared to heading 050 degrees to join radial on departure. Captain and first officer both understood (or recall) cleared to join 096 degree radial to departure. Actual radial is 069 degrees. Unsure if controller or pilot error. While captain (PNF) set up FMS, first officer (PF) intercepted raw data 096 degree radial. Shortly (less than 1 min) after turn to join, departure gave immediate left turn to 030 degrees for traffic and said we had made wrong turn. Not sure if actual loss of separation occurred. Several contributing factors. Glance at departure chart course was consistent with 096 degree course. High magnetic variation (approximately 20 degrees) probably affected perception. 1 crew member had difficulty locating departure chart, so crew was sharing 1 chart. Had both crew members been referencing charts, likelihood of error would have been reduced.

Original NASA ASRS Text

Title: A320 CREW HAD TRACK DEV IN S46 CLASS E AIRSPACE.

Narrative: DEPARTED RWY 16L ON BLUIT 3 DEP. REQUESTED L TURN OFF DEP DUE TO WX (SHOER) S OF ARPT. CLRED TO HDG 050 DEGS TO JOIN RADIAL ON DEP. CAPT AND FO BOTH UNDERSTOOD (OR RECALL) CLRED TO JOIN 096 DEG RADIAL TO DEP. ACTUAL RADIAL IS 069 DEGS. UNSURE IF CTLR OR PLT ERROR. WHILE CAPT (PNF) SET UP FMS, FO (PF) INTERCEPTED RAW DATA 096 DEG RADIAL. SHORTLY (LESS THAN 1 MIN) AFTER TURN TO JOIN, DEP GAVE IMMEDIATE L TURN TO 030 DEGS FOR TFC AND SAID WE HAD MADE WRONG TURN. NOT SURE IF ACTUAL LOSS OF SEPARATION OCCURRED. SEVERAL CONTRIBUTING FACTORS. GLANCE AT DEP CHART COURSE WAS CONSISTENT WITH 096 DEG COURSE. HIGH MAGNETIC VARIATION (APPROX 20 DEGS) PROBABLY AFFECTED PERCEPTION. 1 CREW MEMBER HAD DIFFICULTY LOCATING DEP CHART, SO CREW WAS SHARING 1 CHART. HAD BOTH CREW MEMBERS BEEN REFING CHARTS, LIKELIHOOD OF ERROR WOULD HAVE BEEN REDUCED.

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.