Heading track deviation.

Attributes
ACN	307350
Time
Date	199506
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dna airport : sna
State Reference	CA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure other departure sid : sid enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 26000 flight time type : 1500
ASRS Report	307350
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flight took off from sna for sfo (at PM00 6/xx/95) on a musel 5 departure. We were heading 175 degrees and departure told us to intercept 084 degree radial of sxc, proceed as filed. I line selected sxc 17 by mistake on legs page. There was no sxc or musel listed on my FMC. After activating the selected change we noticed the magenta line did not intercept sxc. As we were returning to our previous heading, departure contacted us saying we were 8 mi off course. We re-entered our clearance and flew the remainder of the flight without a problem. This problem resulted from trying to keep a visual picture with small aircraft in the area and stay with the computer updates. I think the computer possibly dropped out the musel 5 but I have never had this happen before. In the future I will use the fix page to insure sxc/084 degree radial is on the screen before takeoff.

Original NASA ASRS Text

Title: HDG TRACK DEV.

Narrative: FLT TOOK OFF FROM SNA FOR SFO (AT PM00 6/XX/95) ON A MUSEL 5 DEP. WE WERE HDG 175 DEGS AND DEP TOLD US TO INTERCEPT 084 DEG RADIAL OF SXC, PROCEED AS FILED. I LINE SELECTED SXC 17 BY MISTAKE ON LEGS PAGE. THERE WAS NO SXC OR MUSEL LISTED ON MY FMC. AFTER ACTIVATING THE SELECTED CHANGE WE NOTICED THE MAGENTA LINE DID NOT INTERCEPT SXC. AS WE WERE RETURNING TO OUR PREVIOUS HDG, DEP CONTACTED US SAYING WE WERE 8 MI OFF COURSE. WE RE-ENTERED OUR CLRNC AND FLEW THE REMAINDER OF THE FLT WITHOUT A PROB. THIS PROB RESULTED FROM TRYING TO KEEP A VISUAL PICTURE WITH SMALL ACFT IN THE AREA AND STAY WITH THE COMPUTER UPDATES. I THINK THE COMPUTER POSSIBLY DROPPED OUT THE MUSEL 5 BUT I HAVE NEVER HAD THIS HAPPEN BEFORE. IN THE FUTURE I WILL USE THE FIX PAGE TO INSURE SXC/084 DEG RADIAL IS ON THE SCREEN BEFORE TKOF.

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.