Air carrier flight crew departs assigned altitude during STAR into lax.

Attributes
ACN	521490
Time
Date	200108
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : jli.vortac
State Reference	CA
Altitude	msl bound lower : 23500 msl bound upper : 24000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	Large Transport
Flight Phase	descent : vacating altitude descent : intermediate altitude
Route In Use	arrival star : paradise
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	controller military : 10 controller non radar : 11 controller radar : 11 flight time last 90 days : 95 flight time total : 2600 flight time type : 487
ASRS Report	521490
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Denver flight from sal to lax. Aircraft was cleared for the paradise 4 arrival prior to jli. Aircraft level at FL240. Passing jli the first officer (PNF) asked the captain (PF) if he wanted 16000 ft set in altitude window. Captain said yes and asked if we were cleared. First officer said 'we are cleared on the paradise 4 arrival.' captain began descent and first officer told center aircraft was leaving FL240 for 16000 ft. Center said 'negative, maintain FL240.' first officer said 'roger, maintaining FL240, understand we were cleared on the paradise 4 arrival?' center said 'you were cleared on the paradise 4 but altitudes will be given by the next controller (approach).' during this time the aircraft descended to FL235 before returning to FL240. No traffic conflict occurred and nothing else was said by ZLA. The flight continued normally from this point. 2 causal factors contributed to this event. The first officer incorrectly asked to set the next expected altitude in the autoplt and the captain did not completely hear or comprehend the clearance given by center. Only by reporting the departure of FL240 did we prevent a much larger altitude deviation.

Original NASA ASRS Text

Title: ACR FLT CREW DEPARTS ASSIGNED ALT DURING STAR INTO LAX.

Narrative: DENVER FLT FROM SAL TO LAX. ACFT WAS CLRED FOR THE PARADISE 4 ARR PRIOR TO JLI. ACFT LEVEL AT FL240. PASSING JLI THE FO (PNF) ASKED THE CAPT (PF) IF HE WANTED 16000 FT SET IN ALT WINDOW. CAPT SAID YES AND ASKED IF WE WERE CLRED. FO SAID 'WE ARE CLRED ON THE PARADISE 4 ARR.' CAPT BEGAN DSCNT AND FO TOLD CTR ACFT WAS LEAVING FL240 FOR 16000 FT. CTR SAID 'NEGATIVE, MAINTAIN FL240.' FO SAID 'ROGER, MAINTAINING FL240, UNDERSTAND WE WERE CLRED ON THE PARADISE 4 ARR?' CTR SAID 'YOU WERE CLRED ON THE PARADISE 4 BUT ALTS WILL BE GIVEN BY THE NEXT CTLR (APCH).' DURING THIS TIME THE ACFT DSNDED TO FL235 BEFORE RETURNING TO FL240. NO TFC CONFLICT OCCURRED AND NOTHING ELSE WAS SAID BY ZLA. THE FLT CONTINUED NORMALLY FROM THIS POINT. 2 CAUSAL FACTORS CONTRIBUTED TO THIS EVENT. THE FO INCORRECTLY ASKED TO SET THE NEXT EXPECTED ALT IN THE AUTOPLT AND THE CAPT DID NOT COMPLETELY HEAR OR COMPREHEND THE CLRNC GIVEN BY CTR. ONLY BY RPTING THE DEP OF FL240 DID WE PREVENT A MUCH LARGER ALTDEV.

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.