Narrative:

Flight xyz cleared to cross allentown VOR at 13000' and lizza at 11000'. Flight xyz descended 15 mi west of allentown VOR to 12500' when ny center instructed fly xyz to return to 13000', which was immediately accomplished. Flight xyz continued normally, contributing factors were an unexpected and unusual presentation of the clearance 'cross allentown at 13000', lizza at 11000'.' a better clearance would have been 'cross allentown at 13000', expect lizza at 11000'.' the new 'milton 1' arrival is somewhat confusing and too busy. We had not seen this arrival before. We experienced communication problems with ny center, there were at least three exchanges before the clearance was successfully transmitted and read back. The controller became irritated at this problem. The copilot tried to repeat clearance twice without success. Controller was irritated and his reply sounded somewhat sarcastic. The first officer then was able to communication with ny center. The controller's clearance differed from that published on 'milton 1,' the published arrival shows cross five mi west of allentown at 13000'. These factors led to confusion on what to set in the altitude alerting device either 13000' or 11000'? Flight xyz selected 11000' and this in combination with the other factors tended to remove the 13000' crossing altitude restriction from our flight planning in the descent. When we returned to 13000' the controller asked us in what seemed a sarcastic tone if we were confused. When we tried to explain, he said somewhat defensively 'you repeated the clearance back correctly!' in retrospect flight xyz should have set the higher of the two altitudes. The other factor for the captain was the location of the altitude alerting device on the right side of the gear handle and out of my vision. Supplemental information from acn 84915. Contributing factors were unexpected and unusual presentation of the clearance, to cross abe at 13000', cross lizzi at 11000'. A better would have been cross abe at 13000' and 'expect' lizzi at 11000'. The milton 5 STAR shows the 13000' crossing at a point 5 mi west of abe.the milton 5 STAR which we had not seen before is somewhat confusing in that it has an inordinate number of crossing restrictions adding to pilot workload. This led to confusion as to what altitude to set in our altitude alert device, either 13000' or 11000'. We decided to set 11000' and this combined with the other factors mentioned tended to remove the 13000' restriction from our descent planning. In retrospect we should have set 13000', the higher of the two altitudes. Supplemental information from acn 84912. The captain (flying) answered the call. He read back the clearance two times but due to multiple xmissions by other aircraft was unsuccessful to get through. He was a little unsure of the clearance at the time of the attempted readbacks also. He even asked us if we caught the transmission. The first officer asked which altitude he wanted in the altitude alert system to which the captain replied 11000'. Approximately 15 mi west of abe the controller questioned our altitude. The captain immediately pulled up and within seconds we were back to 13000' from approximately 12400'. Contributing factors. Captain was still possibly unsure of clearance. Complexity of arrival procedure. First officer and second officer were involved in descent checks at level off time. Corrective actions. After hearing captain struggle with readbacks we should have questioned the captain insuring he completely understood the clearance. At critical stages in flight, everyone backs up pilot at controls. Do checklist at less critical times. Put highest altitude cleared to in altitude alert system.

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Original NASA ASRS Text

Title: LGT ACR DEVIATED FROM ARTCC CLRNC TO CROSS ABE VORTAC AT 13000' AND LIZZIE INTERSECTION AT 11000'. FLT DESCENDED TO 12400' 15 MI WEST OF ABE BEFORE CORRECTED BY ZNY.

Narrative: FLT XYZ CLRED TO CROSS ALLENTOWN VOR AT 13000' AND LIZZA AT 11000'. FLT XYZ DSNDED 15 MI W OF ALLENTOWN VOR TO 12500' WHEN NY CENTER INSTRUCTED FLY XYZ TO RETURN TO 13000', WHICH WAS IMMEDIATELY ACCOMPLISHED. FLT XYZ CONTINUED NORMALLY, CONTRIBUTING FACTORS WERE AN UNEXPECTED AND UNUSUAL PRESENTATION OF THE CLRNC 'CROSS ALLENTOWN AT 13000', LIZZA AT 11000'.' A BETTER CLRNC WOULD HAVE BEEN 'CROSS ALLENTOWN AT 13000', EXPECT LIZZA AT 11000'.' THE NEW 'MILTON 1' ARR IS SOMEWHAT CONFUSING AND TOO BUSY. WE HAD NOT SEEN THIS ARR BEFORE. WE EXPERIENCED COM PROBS WITH NY CENTER, THERE WERE AT LEAST THREE EXCHANGES BEFORE THE CLRNC WAS SUCCESSFULLY TRANSMITTED AND READ BACK. THE CTLR BECAME IRRITATED AT THIS PROB. THE COPLT TRIED TO REPEAT CLRNC TWICE WITHOUT SUCCESS. CTLR WAS IRRITATED AND HIS REPLY SOUNDED SOMEWHAT SARCASTIC. THE F/O THEN WAS ABLE TO COM WITH NY CENTER. THE CTLR'S CLRNC DIFFERED FROM THAT PUBLISHED ON 'MILTON 1,' THE PUBLISHED ARR SHOWS CROSS FIVE MI W OF ALLENTOWN AT 13000'. THESE FACTORS LED TO CONFUSION ON WHAT TO SET IN THE ALT ALERTING DEVICE EITHER 13000' OR 11000'? FLT XYZ SELECTED 11000' AND THIS IN COMBINATION WITH THE OTHER FACTORS TENDED TO REMOVE THE 13000' XING ALT RESTRICTION FROM OUR FLT PLANNING IN THE DSCNT. WHEN WE RETURNED TO 13000' THE CTLR ASKED US IN WHAT SEEMED A SARCASTIC TONE IF WE WERE CONFUSED. WHEN WE TRIED TO EXPLAIN, HE SAID SOMEWHAT DEFENSIVELY 'YOU REPEATED THE CLRNC BACK CORRECTLY!' IN RETROSPECT FLT XYZ SHOULD HAVE SET THE HIGHER OF THE TWO ALTS. THE OTHER FACTOR FOR THE CAPT WAS THE LOCATION OF THE ALT ALERTING DEVICE ON THE RIGHT SIDE OF THE GEAR HANDLE AND OUT OF MY VISION. SUPPLEMENTAL INFO FROM ACN 84915. CONTRIBUTING FACTORS WERE UNEXPECTED AND UNUSUAL PRESENTATION OF THE CLRNC, TO CROSS ABE AT 13000', CROSS LIZZI AT 11000'. A BETTER WOULD HAVE BEEN CROSS ABE AT 13000' AND 'EXPECT' LIZZI AT 11000'. THE MILTON 5 STAR SHOWS THE 13000' XING AT A POINT 5 MI W OF ABE.THE MILTON 5 STAR WHICH WE HAD NOT SEEN BEFORE IS SOMEWHAT CONFUSING IN THAT IT HAS AN INORDINATE NUMBER OF XING RESTRICTIONS ADDING TO PLT WORKLOAD. THIS LED TO CONFUSION AS TO WHAT ALT TO SET IN OUR ALT ALERT DEVICE, EITHER 13000' OR 11000'. WE DECIDED TO SET 11000' AND THIS COMBINED WITH THE OTHER FACTORS MENTIONED TENDED TO REMOVE THE 13000' RESTRICTION FROM OUR DSCNT PLANNING. IN RETROSPECT WE SHOULD HAVE SET 13000', THE HIGHER OF THE TWO ALTS. SUPPLEMENTAL INFO FROM ACN 84912. THE CAPT (FLYING) ANSWERED THE CALL. HE READ BACK THE CLRNC TWO TIMES BUT DUE TO MULTIPLE XMISSIONS BY OTHER ACFT WAS UNSUCCESSFUL TO GET THROUGH. HE WAS A LITTLE UNSURE OF THE CLRNC AT THE TIME OF THE ATTEMPTED READBACKS ALSO. HE EVEN ASKED US IF WE CAUGHT THE XMISSION. THE F/O ASKED WHICH ALT HE WANTED IN THE ALT ALERT SYS TO WHICH THE CAPT REPLIED 11000'. APPROX 15 MI W OF ABE THE CTLR QUESTIONED OUR ALT. THE CAPT IMMEDIATELY PULLED UP AND WITHIN SECONDS WE WERE BACK TO 13000' FROM APPROX 12400'. CONTRIBUTING FACTORS. CAPT WAS STILL POSSIBLY UNSURE OF CLRNC. COMPLEXITY OF ARR PROC. F/O AND S/O WERE INVOLVED IN DSCNT CHKS AT LEVEL OFF TIME. CORRECTIVE ACTIONS. AFTER HEARING CAPT STRUGGLE WITH READBACKS WE SHOULD HAVE QUESTIONED THE CAPT INSURING HE COMPLETELY UNDERSTOOD THE CLRNC. AT CRITICAL STAGES IN FLT, EVERYONE BACKS UP PLT AT CONTROLS. DO CHKLIST AT LESS CRITICAL TIMES. PUT HIGHEST ALT CLRED TO IN ALT ALERT SYSTEM.

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.