B737-500 flight crew descended to an altitude that ZLA questioned near gvo.

Attributes
ACN	441023
Time
Date	199906
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : gvo.vortac
State Reference	CA
Altitude	msl bound lower : 5000 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Route In Use	arrival : profile descent
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : multi engine pilot : cfi pilot : atp
Experience	flight time last 90 days : 250 flight time total : 11000 flight time type : 2600
ASRS Report	441023
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	441024
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : detected after the fact
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:

About 50 NM north of gvo VOR, both myself and the first officer understood ZLA to clear us down to 5000 ft. I read back 'cleared to 5000 ft.' no response from the controller. Passing 8800 ft, the controller asked if we were going to level. We replied that we were cleared to 5000 ft. At this time the controller said we were cleared to 9000 ft, but now reclred to 7000 ft. After landing, I called ZLA and talked to the shift supervisor. He said that there was no loss of separation or other conflict.

Original NASA ASRS Text

Title: B737-500 FLC DSNDED TO AN ALT THAT ZLA QUESTIONED NEAR GVO.

Narrative: ABOUT 50 NM N OF GVO VOR, BOTH MYSELF AND THE FO UNDERSTOOD ZLA TO CLR US DOWN TO 5000 FT. I READ BACK 'CLRED TO 5000 FT.' NO RESPONSE FROM THE CTLR. PASSING 8800 FT, THE CTLR ASKED IF WE WERE GOING TO LEVEL. WE REPLIED THAT WE WERE CLRED TO 5000 FT. AT THIS TIME THE CTLR SAID WE WERE CLRED TO 9000 FT, BUT NOW RECLRED TO 7000 FT. AFTER LNDG, I CALLED ZLA AND TALKED TO THE SHIFT SUPVR. HE SAID THAT THERE WAS NO LOSS OF SEPARATION OR OTHER CONFLICT.

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.