Narrative:

First officer's 6TH trip on the large transport, since completing training approximately 1 month earlier. Captain had also completed training recently. Details: I was the first officer on the flight. I was operating the aircraft on autoplt at the time. The captain was making the required in-range call to washington national operations at the time. I had just completed a VNAV descent to FL270 when we were given a vector heading followed shortly by a clearance to descend to FL240. Since the captain was on the other radio, I acknowledged the clearance and reset the altitude alert on the mode select panel (MCP) to 24000. I then pulled up the cruise page on the flight management computer (FMC) and entered FL240 into it and executed. In my mind the autoplt/flight director was still in the VNAV mode and in that mode, executing the cruise altitude of 240 should have started a descent to that altitude. The aircraft had, however, leveled off at 270 and transferred into the altitude hold mode, which would not automatically respond to the setting and executing of a new, lower altitude in the FMC. Meanwhile, the captain had tuned the ATIS and I heard from his cockpit speaker that washington national had switched from the north operation we had expected and had set in the FMC to a south operation. I pulled up the arrival page on the FMC and reset the computer to the new arrival while the captain was copying the ATIS. In the meantime, the aircraft continued to cruise at FL270. Shortly thereafter, washington center called and asked to verify our altitude, at which time I realized what had happened and started an immediate descent. There was no indication from center that the failure to descend had jeopardized safety. Other factors: it was approximately nine hours since I had reported for duty at atlanta that morning. I had been called for the trip at about XA30 am for an xd:17 departure. Since I usually allow 3 hours before departure as a time to leave home, and being unsure of how much gas I had and how often the crew bus ran from the parking lot in the early morning, I did not return to bed after the call. I had had about 3 hours sleep at the time of the phone call. In training they emphasized that one pilot should fly and the other should program the FMC. I understood and believe that, however, most of the experience pilots I had been flying with since training seemed to do most of their own FMC management while flying, especially if I was otherwise occupied on the other radio. Following that example, which may work for an experienced large transport pilot but certainly not for one at my level, I fell into the trap they had warned me about! I pushed the buttons, but I did not check the response to the input before going on to something else. No one was flying the aircraft. In the future I will initiate all altitude changes on the MCP (using fl level change) when the other pilot is unable to enter data in the FMC, and will check the basic aircraft instruments for a response to the inputs I make to this complex, multi-faceted automatic flight control system.

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Original NASA ASRS Text

Title: ACR LGT NON ADHERENCE TO ATC CLRNC. FLT CREW FAILED TO START DESCENT AFTER CLRNC READBACK.

Narrative: F/O'S 6TH TRIP ON THE LGT, SINCE COMPLETING TRAINING APPROX 1 MONTH EARLIER. CAPT HAD ALSO COMPLETED TRAINING RECENTLY. DETAILS: I WAS THE F/O ON THE FLT. I WAS OPERATING THE ACFT ON AUTOPLT AT THE TIME. THE CAPT WAS MAKING THE REQUIRED IN-RANGE CALL TO WASHINGTON NATIONAL OPERATIONS AT THE TIME. I HAD JUST COMPLETED A VNAV DESCENT TO FL270 WHEN WE WERE GIVEN A VECTOR HEADING FOLLOWED SHORTLY BY A CLRNC TO DESCEND TO FL240. SINCE THE CAPT WAS ON THE OTHER RADIO, I ACKNOWLEDGED THE CLRNC AND RESET THE ALT ALERT ON THE MODE SELECT PANEL (MCP) TO 24000. I THEN PULLED UP THE CRUISE PAGE ON THE FLT MGMNT COMPUTER (FMC) AND ENTERED FL240 INTO IT AND EXECUTED. IN MY MIND THE AUTOPLT/FLT DIRECTOR WAS STILL IN THE VNAV MODE AND IN THAT MODE, EXECUTING THE CRUISE ALT OF 240 SHOULD HAVE STARTED A DESCENT TO THAT ALT. THE ACFT HAD, HOWEVER, LEVELED OFF AT 270 AND TRANSFERRED INTO THE ALT HOLD MODE, WHICH WOULD NOT AUTOMATICALLY RESPOND TO THE SETTING AND EXECUTING OF A NEW, LOWER ALT IN THE FMC. MEANWHILE, THE CAPT HAD TUNED THE ATIS AND I HEARD FROM HIS COCKPIT SPEAKER THAT WASHINGTON NATIONAL HAD SWITCHED FROM THE NORTH OPERATION WE HAD EXPECTED AND HAD SET IN THE FMC TO A SOUTH OPERATION. I PULLED UP THE ARRIVAL PAGE ON THE FMC AND RESET THE COMPUTER TO THE NEW ARRIVAL WHILE THE CAPT WAS COPYING THE ATIS. IN THE MEANTIME, THE ACFT CONTINUED TO CRUISE AT FL270. SHORTLY THEREAFTER, WASHINGTON CENTER CALLED AND ASKED TO VERIFY OUR ALT, AT WHICH TIME I REALIZED WHAT HAD HAPPENED AND STARTED AN IMMEDIATE DESCENT. THERE WAS NO INDICATION FROM CENTER THAT THE FAILURE TO DESCEND HAD JEOPARDIZED SAFETY. OTHER FACTORS: IT WAS APPROX NINE HOURS SINCE I HAD REPORTED FOR DUTY AT ATLANTA THAT MORNING. I HAD BEEN CALLED FOR THE TRIP AT ABOUT XA30 AM FOR AN XD:17 DEP. SINCE I USUALLY ALLOW 3 HOURS BEFORE DEP AS A TIME TO LEAVE HOME, AND BEING UNSURE OF HOW MUCH GAS I HAD AND HOW OFTEN THE CREW BUS RAN FROM THE PARKING LOT IN THE EARLY MORNING, I DID NOT RETURN TO BED AFTER THE CALL. I HAD HAD ABOUT 3 HOURS SLEEP AT THE TIME OF THE PHONE CALL. IN TRAINING THEY EMPHASIZED THAT ONE PLT SHOULD FLY AND THE OTHER SHOULD PROGRAM THE FMC. I UNDERSTOOD AND BELIEVE THAT, HOWEVER, MOST OF THE EXPERIENCE PLTS I HAD BEEN FLYING WITH SINCE TRAINING SEEMED TO DO MOST OF THEIR OWN FMC MGMNT WHILE FLYING, ESPECIALLY IF I WAS OTHERWISE OCCUPIED ON THE OTHER RADIO. FOLLOWING THAT EXAMPLE, WHICH MAY WORK FOR AN EXPERIENCED LGT PLT BUT CERTAINLY NOT FOR ONE AT MY LEVEL, I FELL INTO THE TRAP THEY HAD WARNED ME ABOUT! I PUSHED THE BUTTONS, BUT I DID NOT CHECK THE RESPONSE TO THE INPUT BEFORE GOING ON TO SOMETHING ELSE. NO ONE WAS FLYING THE ACFT. IN THE FUTURE I WILL INITIATE ALL ALT CHANGES ON THE MCP (USING FL LEVEL CHANGE) WHEN THE OTHER PLT IS UNABLE TO ENTER DATA IN THE FMC, AND WILL CHECK THE BASIC ACFT INSTRUMENTS FOR A RESPONSE TO THE INPUTS I MAKE TO THIS COMPLEX, MULTI-FACETED AUTO FLT CTL 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.