Narrative:

While approaching las on the lynsy 2 arrival, we were cleared to FL280 to cross lynsy intersection at 12000 ft. After receiving this clearance, my first officer left the frequency to obtain the current ATIS. While in the descent, center called with instructions to hold at lynsy. No efc was given, so I requested one twice. I then read back the hold point and the efc. At this point, my first officer came back on and I relayed the holding instructions. As we were passing through 13000 ft, center requested our altitude. My first officer responded with our current altitude and our 'cleared to' altitude of 12000 ft. He responded by clearing us to 12000 ft and informed us we had been instructed to hold at 15000 ft. At lynsy intersection, we were given a turn to a southerly heading. The controller advised us of a possible deviation and to call ZLA after landing. During the call to supervisor at ZLA, I was informed the controller's instructions had included an altitude of 15000 ft. I asked him if the transcript indicated if I had responded to the altitude limitation. He confirmed my response did not include the altitude. I had only responded to the hold fix and efc. This error was caused by improper controller phraseology and failure to confirm the readback of the altitude restr given. Supplemental information from acn 574755: ATC cleared us down to FL280, cross lynsy intersection at 12000 ft. ATC cannot just assume that a flight crew has received a new clearance, they have to get a readback.

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Original NASA ASRS Text

Title: C560 DSNDED 2000 FT BELOW CLRED ALT IN HOLDING PATTERN ENVIRONMENT.

Narrative: WHILE APCHING LAS ON THE LYNSY 2 ARR, WE WERE CLRED TO FL280 TO CROSS LYNSY INTXN AT 12000 FT. AFTER RECEIVING THIS CLRNC, MY FO LEFT THE FREQ TO OBTAIN THE CURRENT ATIS. WHILE IN THE DSCNT, CTR CALLED WITH INSTRUCTIONS TO HOLD AT LYNSY. NO EFC WAS GIVEN, SO I REQUESTED ONE TWICE. I THEN READ BACK THE HOLD POINT AND THE EFC. AT THIS POINT, MY FO CAME BACK ON AND I RELAYED THE HOLDING INSTRUCTIONS. AS WE WERE PASSING THROUGH 13000 FT, CTR REQUESTED OUR ALT. MY FO RESPONDED WITH OUR CURRENT ALT AND OUR 'CLRED TO' ALT OF 12000 FT. HE RESPONDED BY CLRING US TO 12000 FT AND INFORMED US WE HAD BEEN INSTRUCTED TO HOLD AT 15000 FT. AT LYNSY INTXN, WE WERE GIVEN A TURN TO A SOUTHERLY HDG. THE CTLR ADVISED US OF A POSSIBLE DEV AND TO CALL ZLA AFTER LNDG. DURING THE CALL TO SUPVR AT ZLA, I WAS INFORMED THE CTLR'S INSTRUCTIONS HAD INCLUDED AN ALT OF 15000 FT. I ASKED HIM IF THE TRANSCRIPT INDICATED IF I HAD RESPONDED TO THE ALT LIMITATION. HE CONFIRMED MY RESPONSE DID NOT INCLUDE THE ALT. I HAD ONLY RESPONDED TO THE HOLD FIX AND EFC. THIS ERROR WAS CAUSED BY IMPROPER CTLR PHRASEOLOGY AND FAILURE TO CONFIRM THE READBACK OF THE ALT RESTR GIVEN. SUPPLEMENTAL INFO FROM ACN 574755: ATC CLRED US DOWN TO FL280, CROSS LYNSY INTXN AT 12000 FT. ATC CANNOT JUST ASSUME THAT A FLT CREW HAS RECEIVED A NEW CLRNC, THEY HAVE TO GET A READBACK.

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.