Narrative:

While flying the civet 1 arrival into lax, we, an air carrier, were issued a clearance direct to arnes approximately 25 mi east of arnes. Within 30 seconds, a speed restr of 210 KTS was given, we complied. Immediately thereafter a 3RD clearance that we interpreted as to cross 13 mi east of arnes at or below 14000 ft to cross arnes at 10000 ft MSL. At 18 mi east of arnes we were descending through 12700 ft which prompted the ATC controller to state 'I thought I told you to cross 13 mi east of arnes at 14000 ft to cross arnes at 10000 ft.' PNF: 'we thought you said at or below 14000 ft, 13 mi east of arnes.' ATC then cleared us to 12000 ft followed again by a new clearance to cross 7 mi east of arnes at 12000 ft and cross arnes at 10000 ft. We then complied. All the above clrncs were issued with very short notice and not a single expect clearance as is often issued. Contributing factors: ATC deviating from the expected civet 1 arrival. Unusual crossing restr not normally used or expected during an approach into lax. Too many short notice clrncs issued with very little time between each of them. The civet 1 arrival offers several between altitudes and I think we were mentally programmed to receive a between altitude clearance when in fact it was a hard clearance.

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Original NASA ASRS Text

Title: ALTDEV ALT XING RESTR -- FLC OF AN ACR MISINTERPRETED A XING RESTR ALT AS BEING AT OR BELOW THE ASSIGNED ALT.

Narrative: WHILE FLYING THE CIVET 1 ARR INTO LAX, WE, AN ACR, WERE ISSUED A CLRNC DIRECT TO ARNES APPROX 25 MI E OF ARNES. WITHIN 30 SECONDS, A SPD RESTR OF 210 KTS WAS GIVEN, WE COMPLIED. IMMEDIATELY THEREAFTER A 3RD CLRNC THAT WE INTERPRETED AS TO CROSS 13 MI E OF ARNES AT OR BELOW 14000 FT TO CROSS ARNES AT 10000 FT MSL. AT 18 MI E OF ARNES WE WERE DSNDING THROUGH 12700 FT WHICH PROMPTED THE ATC CTLR TO STATE 'I THOUGHT I TOLD YOU TO CROSS 13 MI E OF ARNES AT 14000 FT TO CROSS ARNES AT 10000 FT.' PNF: 'WE THOUGHT YOU SAID AT OR BELOW 14000 FT, 13 MI E OF ARNES.' ATC THEN CLRED US TO 12000 FT FOLLOWED AGAIN BY A NEW CLRNC TO CROSS 7 MI E OF ARNES AT 12000 FT AND CROSS ARNES AT 10000 FT. WE THEN COMPLIED. ALL THE ABOVE CLRNCS WERE ISSUED WITH VERY SHORT NOTICE AND NOT A SINGLE EXPECT CLRNC AS IS OFTEN ISSUED. CONTRIBUTING FACTORS: ATC DEVIATING FROM THE EXPECTED CIVET 1 ARR. UNUSUAL XING RESTR NOT NORMALLY USED OR EXPECTED DURING AN APCH INTO LAX. TOO MANY SHORT NOTICE CLRNCS ISSUED WITH VERY LITTLE TIME BTWN EACH OF THEM. THE CIVET 1 ARR OFFERS SEVERAL BTWN ALTS AND I THINK WE WERE MENTALLY PROGRAMMED TO RECEIVE A BTWN ALT CLRNC WHEN IN FACT IT WAS A HARD CLRNC.

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.