S80 crew failed to comply with controller's clearance.

Attributes
ACN	434670
Time
Date	199904
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : pke.vortac
State Reference	CA
Altitude	msl single value : 33000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	434670
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other spatial deviation
Independent Detector	atc equipment other atc equipment : radar other controllera other flight crewa
Resolutory Action	controller : issued advisory none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were given direct pke and engaged the GPS to the autoplt. Navigation was displayed on the FMS, and we were set. For some reason, the GPS switched to heading select without our knowing. ATC asked us why we were going to miss pke by 10 mi. We corrected the error, and I do not believe that a conflict occurred. ATC said it was no problem. I will pay more attention to the GPS in the future, and make sure that it does not slip into heading select again. The rest of the flight the GPS did not go into heading select.

Original NASA ASRS Text

Title: S80 CREW FAILED TO COMPLY WITH CTLR'S CLRNC.

Narrative: WE WERE GIVEN DIRECT PKE AND ENGAGED THE GPS TO THE AUTOPLT. NAV WAS DISPLAYED ON THE FMS, AND WE WERE SET. FOR SOME REASON, THE GPS SWITCHED TO HDG SELECT WITHOUT OUR KNOWING. ATC ASKED US WHY WE WERE GOING TO MISS PKE BY 10 MI. WE CORRECTED THE ERROR, AND I DO NOT BELIEVE THAT A CONFLICT OCCURRED. ATC SAID IT WAS NO PROB. I WILL PAY MORE ATTN TO THE GPS IN THE FUTURE, AND MAKE SURE THAT IT DOES NOT SLIP INTO HDG SELECT AGAIN. THE REST OF THE FLT THE GPS DID NOT GO INTO HDG SELECT.

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.