Narrative:

We were being handled by ZDC ATC. During the flight; we experienced 2 accidental altdevs. Preceding the first incident; we were given an unusually high number of 'climb and maintain' instructions that changed our altitude by only 1000 ft at a time. Also; there were a high number of instructions for waypoint changes; directing us to fly 'direct to xyz' waypoint. This required a high number of FMS keyboard entry changes in a short amount of time. Also; at the time; we were having difficulty entering navigation waypoint data in the FMS computer. This was a distraction to both crew members. Normally; the FMS data entry function is a copilot duty; so the PIC can be focused on flying the aircraft. During this time; the PIC was performing the data entry and; therefore; was heads down and not focused on the primary function of flying the aircraft. We were asked by ATC to climb and maintain 14000 ft. As the copilot; I set '14000 ft' in the altitude alerter and set the 'arm' button on the autoplt altitude hold feature; calling out '14000 ft; set and armed.' for some unknown reason; the altitude arm feature of the altitude hold function of the autoplt did not 'catch' and we climbed through 14000 ft to approximately 14400 ft. I had been heads down; looking at the navigation charts for waypoint data to enter into the FMS and did not notice the altitude overshoot. The controller queried us; saying we had been cleared to 14000 ft and to descend and maintain 14000 ft; which we did with no further discussion on the matter with ATC. Later; we received an instruction; on what I thought I heard 'climb and maintain one nine; nineteen.' I read back to ATC (exactly what I thought I heard) 'one nine; nineteen.' this is pilot/controller phraseology for 19000 ft or FL190. I set FL190 in the altitude alerter and set the 'arm' button on the autoplt altitude hold feature; calling out '190; set and armed.' instead of 'climb and maintain one nine; nineteen;' the controller had apparently said 'climb and maintain one five; fifteen.' although I had read back the instruction 'climb and maintain one nine; nineteen;' the controller had apparently not heard me correctly and did not correct me to the 15000 ft original instruction. This is what the readback is all about; assuring accurate communications. We had climbed beyond 15000 ft and were then instructed by ATC to descend and maintain 15000 ft; which we did without further discussion on the matter with ATC. I asked the PIC what he heard as our altitude instruction and the reply was 'I'm not sure.' in both cases; the pilot was distraction from the primary task of flying the aircraft by entering data in the FMS. I was distraction from assisting the PIC on the flight condition of the aircraft by looking at a chart for navigation data. At all times; at least 1 crew member needs to be 'flying the aircraft' while the other crew member attends to the other cockpit duties. In the examples above; this was not the case. Both crew members were preoccupied with other cockpit duties and in the one case miscom caused the deviation.

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Original NASA ASRS Text

Title: C560 FLT CREWHANDLED BY ZDC EXPERIENCES 2 ALTDEVS DURING CLBOUT.

Narrative: WE WERE BEING HANDLED BY ZDC ATC. DURING THE FLT; WE EXPERIENCED 2 ACCIDENTAL ALTDEVS. PRECEDING THE FIRST INCIDENT; WE WERE GIVEN AN UNUSUALLY HIGH NUMBER OF 'CLB AND MAINTAIN' INSTRUCTIONS THAT CHANGED OUR ALT BY ONLY 1000 FT AT A TIME. ALSO; THERE WERE A HIGH NUMBER OF INSTRUCTIONS FOR WAYPOINT CHANGES; DIRECTING US TO FLY 'DIRECT TO XYZ' WAYPOINT. THIS REQUIRED A HIGH NUMBER OF FMS KEYBOARD ENTRY CHANGES IN A SHORT AMOUNT OF TIME. ALSO; AT THE TIME; WE WERE HAVING DIFFICULTY ENTERING NAV WAYPOINT DATA IN THE FMS COMPUTER. THIS WAS A DISTR TO BOTH CREW MEMBERS. NORMALLY; THE FMS DATA ENTRY FUNCTION IS A COPLT DUTY; SO THE PIC CAN BE FOCUSED ON FLYING THE ACFT. DURING THIS TIME; THE PIC WAS PERFORMING THE DATA ENTRY AND; THEREFORE; WAS HEADS DOWN AND NOT FOCUSED ON THE PRIMARY FUNCTION OF FLYING THE ACFT. WE WERE ASKED BY ATC TO CLB AND MAINTAIN 14000 FT. AS THE COPLT; I SET '14000 FT' IN THE ALT ALERTER AND SET THE 'ARM' BUTTON ON THE AUTOPLT ALT HOLD FEATURE; CALLING OUT '14000 FT; SET AND ARMED.' FOR SOME UNKNOWN REASON; THE ALT ARM FEATURE OF THE ALT HOLD FUNCTION OF THE AUTOPLT DID NOT 'CATCH' AND WE CLBED THROUGH 14000 FT TO APPROX 14400 FT. I HAD BEEN HEADS DOWN; LOOKING AT THE NAV CHARTS FOR WAYPOINT DATA TO ENTER INTO THE FMS AND DID NOT NOTICE THE ALT OVERSHOOT. THE CTLR QUERIED US; SAYING WE HAD BEEN CLRED TO 14000 FT AND TO DSND AND MAINTAIN 14000 FT; WHICH WE DID WITH NO FURTHER DISCUSSION ON THE MATTER WITH ATC. LATER; WE RECEIVED AN INSTRUCTION; ON WHAT I THOUGHT I HEARD 'CLB AND MAINTAIN ONE NINE; NINETEEN.' I READ BACK TO ATC (EXACTLY WHAT I THOUGHT I HEARD) 'ONE NINE; NINETEEN.' THIS IS PLT/CTLR PHRASEOLOGY FOR 19000 FT OR FL190. I SET FL190 IN THE ALT ALERTER AND SET THE 'ARM' BUTTON ON THE AUTOPLT ALT HOLD FEATURE; CALLING OUT '190; SET AND ARMED.' INSTEAD OF 'CLB AND MAINTAIN ONE NINE; NINETEEN;' THE CTLR HAD APPARENTLY SAID 'CLB AND MAINTAIN ONE FIVE; FIFTEEN.' ALTHOUGH I HAD READ BACK THE INSTRUCTION 'CLB AND MAINTAIN ONE NINE; NINETEEN;' THE CTLR HAD APPARENTLY NOT HEARD ME CORRECTLY AND DID NOT CORRECT ME TO THE 15000 FT ORIGINAL INSTRUCTION. THIS IS WHAT THE READBACK IS ALL ABOUT; ASSURING ACCURATE COMS. WE HAD CLBED BEYOND 15000 FT AND WERE THEN INSTRUCTED BY ATC TO DSND AND MAINTAIN 15000 FT; WHICH WE DID WITHOUT FURTHER DISCUSSION ON THE MATTER WITH ATC. I ASKED THE PIC WHAT HE HEARD AS OUR ALT INSTRUCTION AND THE REPLY WAS 'I'M NOT SURE.' IN BOTH CASES; THE PLT WAS DISTR FROM THE PRIMARY TASK OF FLYING THE ACFT BY ENTERING DATA IN THE FMS. I WAS DISTR FROM ASSISTING THE PIC ON THE FLT CONDITION OF THE ACFT BY LOOKING AT A CHART FOR NAV DATA. AT ALL TIMES; AT LEAST 1 CREW MEMBER NEEDS TO BE 'FLYING THE ACFT' WHILE THE OTHER CREW MEMBER ATTENDS TO THE OTHER COCKPIT DUTIES. IN THE EXAMPLES ABOVE; THIS WAS NOT THE CASE. BOTH CREW MEMBERS WERE PREOCCUPIED WITH OTHER COCKPIT DUTIES AND IN THE ONE CASE MISCOM CAUSED THE DEV.

Data retrieved from NASA's ASRS site as of January 2009 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.