Clearance confusion, lack of coordination. Possible altitude deviation.

Attributes
ACN	116060
Time
Date	198907
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : hec
State Reference	CA
Altitude	msl bound lower : 12000 msl bound upper : 24000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute airway : zla
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : private pilot : instrument pilot : commercial
Experience	flight time last 90 days : 80 flight time total : 3000 flight time type : 900
ASRS Report	116060
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 12000
ASRS Report	116061
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation

Narrative:

During en route descent into ont we were given a descent clearance pilot discretion to FL240 cross dawna at 12,000'. Because of radio chatter and a cluttered frequency we requested a confirmation of the clearance and were given the same instructions. We were handed off to ZLA (126.35) and after passing FL225 we were told we were only cleared to FL240, contradicting our earlier clearance. We were then given clearance to 17,000'.

Original NASA ASRS Text

Title: CLRNC CONFUSION, LACK OF COORD. POSSIBLE ALT DEVIATION.

Narrative: DURING ENRTE DSCNT INTO ONT WE WERE GIVEN A DSCNT CLRNC PLT DISCRETION TO FL240 CROSS DAWNA AT 12,000'. BECAUSE OF RADIO CHATTER AND A CLUTTERED FREQ WE REQUESTED A CONFIRMATION OF THE CLRNC AND WERE GIVEN THE SAME INSTRUCTIONS. WE WERE HANDED OFF TO ZLA (126.35) AND AFTER PASSING FL225 WE WERE TOLD WE WERE ONLY CLRED TO FL240, CONTRADICTING OUR EARLIER CLRNC. WE WERE THEN GIVEN CLRNC TO 17,000'.

Data retrieved from NASA's ASRS site as of August 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.