Narrative:

Note: copilot on first line sequence after completing training and chkflts with training captain, no previous jet experience, previous position with this air carrier was second officer (3 yrs), background commuter carrier, non military. The incident occurred on the third leg of 6 legs scheduled to fly that day, layover was scheduled for 17+44 hours after an 11+46 hour scheduled on duty day. Mob departure cleared air carrier to continue climb to 17000' and gave a heading to intercept J37 to mgm. Copilot read back clearance, clearly stating climb to 17000' and set 17000' in the assigned altitude readout of the altitude alert indicator panel. Captain/reporter flying aircraft commenced climb to 17000', passing 13500' ATC requested what altitude we were climbing to, clearance was to 10000', requested we stop climb at 14000'. Copilot responded that we were cleared to 17000', that was read back to ATC. Departure requested we change to hou center. Copilot checked in with hou center at 14000', hou requested to know what altitude we were cleared to. Copilot responded our understanding was 17000'. An obvious mix up occurred. Captain/reporter also stated to hou center I understood cleared to climb to 17000'. The problem was in communications. The crew flying the aircraft understood a specific altitude to climb to and read back that clearance. ATC did not challenge the readback, so we assumed that we were cleared as was read back and commenced climb to that altitude. This is an ongoing problem in aviation. It requires constant vigilance on the part of ATC and pilots that what is desired is correctly stated, what is heard is correctly responded to, and that the response is in fact what was initially stated as the clearance. While it may not have occurred at this facility on this day with regard to this occurrence, I have noted an increasing amount of ATC usage of 2 frequencys being used by 1 controller, ie, I cannot hear the responses from whomever ATC is controling and I assume vice versa. Many calls are not responded to in a timely manner because of this and adds to the possibility of a communications breakdown. Also, what has been increasingly being utilized by ATC is the same controller handling departures and arrs, again making timely clearance and response difficult. I also suggest that this type of control is difficult to separate in the mind of the controller and materially adds and detracts from ATC workload. A further consideration on this occurrence would be the heavier workload imposed on a 2 member flight crew particularly heavier due to the copilot recent upgrade from engineer after 3 yrs of PNF positions, plus this series of flts being a first time experience for the copilot.

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Original NASA ASRS Text

Title: CLRNC READ BACK AS CLIMB AND MAINTAIN 17000'. DEP CTLR ADVISED CLRNC WAS TO MAINTAIN 10000'. NO CONFLICT.

Narrative: NOTE: COPLT ON FIRST LINE SEQUENCE AFTER COMPLETING TRNING AND CHKFLTS WITH TRNING CAPT, NO PREVIOUS JET EXPERIENCE, PREVIOUS POS WITH THIS ACR WAS S/O (3 YRS), BACKGROUND COMMUTER CARRIER, NON MIL. THE INCIDENT OCCURRED ON THE THIRD LEG OF 6 LEGS SCHEDULED TO FLY THAT DAY, LAYOVER WAS SCHEDULED FOR 17+44 HRS AFTER AN 11+46 HR SCHEDULED ON DUTY DAY. MOB DEP CLRED ACR TO CONTINUE CLB TO 17000' AND GAVE A HDG TO INTERCEPT J37 TO MGM. COPLT READ BACK CLRNC, CLEARLY STATING CLB TO 17000' AND SET 17000' IN THE ASSIGNED ALT READOUT OF THE ALT ALERT INDICATOR PANEL. CAPT/RPTR FLYING ACFT COMMENCED CLB TO 17000', PASSING 13500' ATC REQUESTED WHAT ALT WE WERE CLBING TO, CLRNC WAS TO 10000', REQUESTED WE STOP CLB AT 14000'. COPLT RESPONDED THAT WE WERE CLRED TO 17000', THAT WAS READ BACK TO ATC. DEP REQUESTED WE CHANGE TO HOU CENTER. COPLT CHKED IN WITH HOU CENTER AT 14000', HOU REQUESTED TO KNOW WHAT ALT WE WERE CLRED TO. COPLT RESPONDED OUR UNDERSTANDING WAS 17000'. AN OBVIOUS MIX UP OCCURRED. CAPT/RPTR ALSO STATED TO HOU CENTER I UNDERSTOOD CLRED TO CLB TO 17000'. THE PROB WAS IN COMS. THE CREW FLYING THE ACFT UNDERSTOOD A SPECIFIC ALT TO CLB TO AND READ BACK THAT CLRNC. ATC DID NOT CHALLENGE THE READBACK, SO WE ASSUMED THAT WE WERE CLRED AS WAS READ BACK AND COMMENCED CLB TO THAT ALT. THIS IS AN ONGOING PROB IN AVIATION. IT REQUIRES CONSTANT VIGILANCE ON THE PART OF ATC AND PLTS THAT WHAT IS DESIRED IS CORRECTLY STATED, WHAT IS HEARD IS CORRECTLY RESPONDED TO, AND THAT THE RESPONSE IS IN FACT WHAT WAS INITIALLY STATED AS THE CLRNC. WHILE IT MAY NOT HAVE OCCURRED AT THIS FAC ON THIS DAY WITH REGARD TO THIS OCCURRENCE, I HAVE NOTED AN INCREASING AMOUNT OF ATC USAGE OF 2 FREQS BEING USED BY 1 CTLR, IE, I CANNOT HEAR THE RESPONSES FROM WHOMEVER ATC IS CTLING AND I ASSUME VICE VERSA. MANY CALLS ARE NOT RESPONDED TO IN A TIMELY MANNER BECAUSE OF THIS AND ADDS TO THE POSSIBILITY OF A COMS BREAKDOWN. ALSO, WHAT HAS BEEN INCREASINGLY BEING UTILIZED BY ATC IS THE SAME CTLR HANDLING DEPS AND ARRS, AGAIN MAKING TIMELY CLRNC AND RESPONSE DIFFICULT. I ALSO SUGGEST THAT THIS TYPE OF CTL IS DIFFICULT TO SEPARATE IN THE MIND OF THE CTLR AND MATERIALLY ADDS AND DETRACTS FROM ATC WORKLOAD. A FURTHER CONSIDERATION ON THIS OCCURRENCE WOULD BE THE HEAVIER WORKLOAD IMPOSED ON A 2 MEMBER FLT CREW PARTICULARLY HEAVIER DUE TO THE COPLT RECENT UPGRADE FROM ENGINEER AFTER 3 YRS OF PNF POSITIONS, PLUS THIS SERIES OF FLTS BEING A FIRST TIME EXPERIENCE FOR THE COPLT.

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.