Narrative:

PIC was on the #2 communication with company dispatch while sic (reporter) was flying and handling ATC communications on the #1 communication. Center controller requested latitude/long coordinates of our destination airport. Sic called up data on the LORAN and responded with coordinate data to controller. Approximately 1 1/2-2 mins later, center controller advised, 'you were cleared to FL310, I show you at FL334, descend and maintain FL310.' with sic still flying, an immediate descent was begun to FL310. At approximately time of reaching FL310, center again advised of our altitude deviation and again instructed us to return to FL310. At this time, with the aircraft level at or near FL310, sic responded with the phrase to ATC, small transport. Center controller then instructed small transport to contact ZID. The aircraft's altitude alert system did not report at any time during this segment of flight with either an audio or visual indication, even thought it had been properly set to FL310. It is easy and routine to rely on equipment to work as it should. In this case, the altitude alerter with 2 lights and an audio tone for reminder. Equipment which we rely on routinely for hundreds or thousands of times can and does fail. Unfortunately, in our case, this failure occurred while both crewmembers were separately distracted with other things and not watching closely enough the flight's progress. In the future, we will keep nonflying activities, such as contact on company frequency, to an absolute minimum until a less 'critical phase of flight' is attained, i.e., cruise flight where altitude changes of deviations are unlikely. Better cockpit management and crew coordination.

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Original NASA ASRS Text

Title: ALT DEVIATION, OVERSHOOT. ACFT EQUIPMENT PROBLEM.

Narrative: PIC WAS ON THE #2 COM WITH COMPANY DISPATCH WHILE SIC (RPTR) WAS FLYING AND HANDLING ATC COMS ON THE #1 COM. CENTER CTLR REQUESTED LAT/LONG COORDINATES OF OUR DEST ARPT. SIC CALLED UP DATA ON THE LORAN AND RESPONDED WITH COORDINATE DATA TO CTLR. APPROX 1 1/2-2 MINS LATER, CENTER CTLR ADVISED, 'YOU WERE CLRED TO FL310, I SHOW YOU AT FL334, DSND AND MAINTAIN FL310.' WITH SIC STILL FLYING, AN IMMEDIATE DSCNT WAS BEGUN TO FL310. AT APPROX TIME OF REACHING FL310, CENTER AGAIN ADVISED OF OUR ALT DEVIATION AND AGAIN INSTRUCTED US TO RETURN TO FL310. AT THIS TIME, WITH THE ACFT LEVEL AT OR NEAR FL310, SIC RESPONDED WITH THE PHRASE TO ATC, SMT. CENTER CTLR THEN INSTRUCTED SMT TO CONTACT ZID. THE ACFT'S ALT ALERT SYS DID NOT RPT AT ANY TIME DURING THIS SEGMENT OF FLT WITH EITHER AN AUDIO OR VISUAL INDICATION, EVEN THOUGHT IT HAD BEEN PROPERLY SET TO FL310. IT IS EASY AND ROUTINE TO RELY ON EQUIP TO WORK AS IT SHOULD. IN THIS CASE, THE ALT ALERTER WITH 2 LIGHTS AND AN AUDIO TONE FOR REMINDER. EQUIP WHICH WE RELY ON ROUTINELY FOR HUNDREDS OR THOUSANDS OF TIMES CAN AND DOES FAIL. UNFORTUNATELY, IN OUR CASE, THIS FAILURE OCCURRED WHILE BOTH CREWMEMBERS WERE SEPARATELY DISTRACTED WITH OTHER THINGS AND NOT WATCHING CLOSELY ENOUGH THE FLT'S PROGRESS. IN THE FUTURE, WE WILL KEEP NONFLYING ACTIVITIES, SUCH AS CONTACT ON COMPANY FREQ, TO AN ABSOLUTE MINIMUM UNTIL A LESS 'CRITICAL PHASE OF FLT' IS ATTAINED, I.E., CRUISE FLT WHERE ALT CHANGES OF DEVIATIONS ARE UNLIKELY. BETTER COCKPIT MGMNT AND CREW COORD.

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.