Clearance confusion near needles, ca.

Attributes
ACN	465640
Time
Date	200003
Day	Sun
Local Time Of Day	0601 To 1200
Place
State Reference	CA
Altitude	msl bound lower : 31000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc tower : fll.tower
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp pilot : multi engine
Experience	flight time last 90 days : 220 flight time total : 5000 flight time type : 750
ASRS Report	465640
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : private pilot : multi engine pilot : instrument pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 150 flight time total : 9000 flight time type : 1000
ASRS Report	465225
Events
Anomaly	altitude deviation : excursion from assigned altitude
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

50 mi east of eed at FL350, instructed to cross eed at FL310. Was going to start descent about 15 mi out. About 30 mi from eed, controller told us to start our descent now to FL330 for traffic. I repeated back to start down now to FL330 to cross eed at FL310. No correction back. Controller called out traffic 3000 ft below us. I told him we were descending past FL324 to FL310. He rogered our call. A min later, he asked us why we weren't at our assigned altitude of FL330. I said because of our instructions to cross eed at FL310. I asked him if he wanted us to level at FL324 or climb to FL330. He said no, just continue to FL310. Cause: controller not replying to our readback to descend to FL310. I read back our continuing descent to FL310 because of the ambiguity of the clearance to FL330. With no reply back for correction, we flew to FL310, as previously cleared. Solution: controller be more specific. Pilots inquire if any doubt.

Original NASA ASRS Text

Title: CLRNC CONFUSION NEAR NEEDLES, CA.

Narrative: 50 MI E OF EED AT FL350, INSTRUCTED TO CROSS EED AT FL310. WAS GOING TO START DSCNT ABOUT 15 MI OUT. ABOUT 30 MI FROM EED, CTLR TOLD US TO START OUR DSCNT NOW TO FL330 FOR TFC. I REPEATED BACK TO START DOWN NOW TO FL330 TO CROSS EED AT FL310. NO CORRECTION BACK. CTLR CALLED OUT TFC 3000 FT BELOW US. I TOLD HIM WE WERE DSNDING PAST FL324 TO FL310. HE ROGERED OUR CALL. A MIN LATER, HE ASKED US WHY WE WEREN'T AT OUR ASSIGNED ALT OF FL330. I SAID BECAUSE OF OUR INSTRUCTIONS TO CROSS EED AT FL310. I ASKED HIM IF HE WANTED US TO LEVEL AT FL324 OR CLB TO FL330. HE SAID NO, JUST CONTINUE TO FL310. CAUSE: CTLR NOT REPLYING TO OUR READBACK TO DSND TO FL310. I READ BACK OUR CONTINUING DSCNT TO FL310 BECAUSE OF THE AMBIGUITY OF THE CLRNC TO FL330. WITH NO REPLY BACK FOR CORRECTION, WE FLEW TO FL310, AS PREVIOUSLY CLRED. SOLUTION: CTLR BE MORE SPECIFIC. PLTS INQUIRE IF ANY DOUBT.

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.