B737-700 flight crew have a track deviation on departure.

Attributes
ACN	689996
Time
Date	200603
Local Time Of Day	0601 To 1200
Place
Locale Reference	intersection : beads
State Reference	NY
Altitude	msl single value : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	departure : other published ifr departure
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 160 flight time total : 2700 flight time type : 160
ASRS Report	689996
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 150 flight time total : 13000 flight time type : 6500
ASRS Report	689997
Events
Anomaly	non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended or assigned course
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

Shortly after departure from isp we were given direct beads (approximately 080 degree heading) then as filed. At 15000 ft in the climb; autoplt engaged; LNAV engaged as we approached beads (approximately 7 NM) and I started a lead turn (autoplt/LNAV) to intercept the course to the next fix of emjay. The new course was roughly a 150 degree course reversal from our previous course into beads and the early lead turn didn't seem unusual with the strong tailwind. 1/2 way through the turn; the ATC controller directed us to roll out on our current heading (150 degrees) and wanted to know why we hadn't flown to beads prior to starting our turn. Shortly after; ATC cleared us back on course. After landing; the captain placed a call to our ATC specialist and informed him of the situation. Supplemental information from acn 689997: after we stopped the turn; the controller asked if we were given a heading by departure. I replied in the negative and he told us we were 10 mi from beads. By our display and instrumentation; it did not appear to be the case but we did receive an 'unable to comply with rnp navigation' message earlier in the flight. I did not consider this until writing this report. From my perspective; nothing seemed to be out of the ordinary.

Original NASA ASRS Text

Title: B737-700 FLT CREW HAVE A TRACK DEV ON DEP.

Narrative: SHORTLY AFTER DEP FROM ISP WE WERE GIVEN DIRECT BEADS (APPROX 080 DEG HDG) THEN AS FILED. AT 15000 FT IN THE CLB; AUTOPLT ENGAGED; LNAV ENGAGED AS WE APCHED BEADS (APPROX 7 NM) AND I STARTED A LEAD TURN (AUTOPLT/LNAV) TO INTERCEPT THE COURSE TO THE NEXT FIX OF EMJAY. THE NEW COURSE WAS ROUGHLY A 150 DEG COURSE REVERSAL FROM OUR PREVIOUS COURSE INTO BEADS AND THE EARLY LEAD TURN DIDN'T SEEM UNUSUAL WITH THE STRONG TAILWIND. 1/2 WAY THROUGH THE TURN; THE ATC CTLR DIRECTED US TO ROLL OUT ON OUR CURRENT HDG (150 DEGS) AND WANTED TO KNOW WHY WE HADN'T FLOWN TO BEADS PRIOR TO STARTING OUR TURN. SHORTLY AFTER; ATC CLRED US BACK ON COURSE. AFTER LNDG; THE CAPT PLACED A CALL TO OUR ATC SPECIALIST AND INFORMED HIM OF THE SIT. SUPPLEMENTAL INFO FROM ACN 689997: AFTER WE STOPPED THE TURN; THE CTLR ASKED IF WE WERE GIVEN A HDG BY DEP. I REPLIED IN THE NEGATIVE AND HE TOLD US WE WERE 10 MI FROM BEADS. BY OUR DISPLAY AND INSTRUMENTATION; IT DID NOT APPEAR TO BE THE CASE BUT WE DID RECEIVE AN 'UNABLE TO COMPLY WITH RNP NAV' MESSAGE EARLIER IN THE FLT. I DID NOT CONSIDER THIS UNTIL WRITING THIS RPT. FROM MY PERSPECTIVE; NOTHING SEEMED TO BE OUT OF THE ORDINARY.

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.