B737 proceeds on wrong course from habit rather than from the clearance as given departing iad.

Attributes
ACN	447740
Time
Date	199908
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : iad.airport
State Reference	VA
Altitude	msl single value : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc tower : ric.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	cruise : level
Route In Use	enroute airway : j6.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 180 flight time total : 5000 flight time type : 850
ASRS Report	447740
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : clearance non adherence : far other spatial deviation
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	controller : issued new clearance controller : issued alert flight crew : became reoriented flight crew : returned to intended or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Depart iad en route to fll. During numerous radar vectors, we were given fly heading to intercept J61 on course. Our routing was daily J61 hobbs J193. I did not hear the clearance and asked the captain to confirm present heading to intercept J193. He said, 'yes, that's right.' a few mins later ATC called and said we were 5 mi left of course turn right and intercept J61. The captain then said, to me, 'is that what you asked me?' I said, 'yes.' he said, 'sorry.' captain should not have confirmed clearance unless he was sure. First officer could have asked ATC for clarification even though captain confirmed clearance, checking our course off J61. I had us 10 degrees at 22 mi from ott VOR (approximately 4 mi off course). No TCASII or traffic noted in area. We made right turn and reintercepted J61.

Original NASA ASRS Text

Title: B737 PROCEEDS ON WRONG COURSE FROM HABIT RATHER THAN FROM THE CLRNC AS GIVEN DEPARTING IAD.

Narrative: DEPART IAD ENRTE TO FLL. DURING NUMEROUS RADAR VECTORS, WE WERE GIVEN FLY HEADING TO INTERCEPT J61 ON COURSE. OUR ROUTING WAS DAILY J61 HOBBS J193. I DID NOT HEAR THE CLRNC AND ASKED THE CAPT TO CONFIRM PRESENT HEADING TO INTERCEPT J193. HE SAID, 'YES, THAT'S RIGHT.' A FEW MINS LATER ATC CALLED AND SAID WE WERE 5 MI L OF COURSE TURN R AND INTERCEPT J61. THE CAPT THEN SAID, TO ME, 'IS THAT WHAT YOU ASKED ME?' I SAID, 'YES.' HE SAID, 'SORRY.' CAPT SHOULD NOT HAVE CONFIRMED CLRNC UNLESS HE WAS SURE. FO COULD HAVE ASKED ATC FOR CLARIFICATION EVEN THOUGH CAPT CONFIRMED CLRNC, CHKING OUR COURSE OFF J61. I HAD US 10 DEGS AT 22 MI FROM OTT VOR (APPROX 4 MI OFF COURSE). NO TCASII OR TFC NOTED IN AREA. WE MADE R TURN AND REINTERCEPTED J61.

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.