Narrative:

On 5/90 I was acting as first officer of flight operating between dsm and phl. The aircraft, heavy transport, departed dsm with the captain doing the flying. Our initial route of flight was dsm J-10 to iow and then J-60 to jot. We were using vors as our primary navigation mode, however, we were also equipped with a single VLF omega unit. The captain indicated a desire to overfly iow VOR to establish the accuracy of the omega unit. During our climb en route to iow ATC issued a radar vector which took us slightly south of J-10. Some time later ATC advised that we were cleared to jot and gave us a frequency change. I was unsure if the captain would accept this clearance since he would not be able to update the omega over iow VOR. I started to question him on this when I saw him reset the course on the HSI and begin updating the omega. I therefore assumed the clearance satisfactory and then proceeded to contact center on the new frequency. Upon contact with center I reported that we were proceeding to jot. The captain meanwhile had the aircraft in a left turn. I then became occupied with other cockpit duties for a short time. ATC then called and asked if we were proceeding direct jot. I replied that we were. Once I made the reply I noticed that we were still turning left and were considerably beyond the heading required for direct jot. Apparently the captain was still intent on overflying iow and had failed to hear the previous clearance to jot, hearing not what was said, but what he expected to hear. The captain then realized the situation and spoke with ATC directly, saying that he had misunderstood the clearance. ATC then advised that we were getting close to another aircraft's airspace. We then turned immediately and flew directly to jot. ATC later advised that there was 'no problem' with our course deviation. Our close proximity to iow when we were cleared direct to jot required the captain to change course 50 to 60 degrees in order to proceed direct to iow. This large heading change in a short time caused our track to deviate from our cleared course very quickly. ATC soon noticed this change and inquired. I undoubtedly would have caught the error in another few seconds, once I had completed the task at hand. This illustrates perfectly how quickly things can go wrong and drives home the need to properly balance the time spent between performing cockpit duties and monitoring the aircraft. This is also a good example of miscom between cockpit crew members. I thought we were on the same 'wavelength' when we obviously weren't.

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Original NASA ASRS Text

Title: ACR HVT TRACK HEADING DEVIATION DURING CLIMB OUT FROM DSM.

Narrative: ON 5/90 I WAS ACTING AS F/O OF FLT OPERATING BTWN DSM AND PHL. THE ACFT, HVT, DEPARTED DSM WITH THE CAPT DOING THE FLYING. OUR INITIAL RTE OF FLT WAS DSM J-10 TO IOW AND THEN J-60 TO JOT. WE WERE USING VORS AS OUR PRIMARY NAV MODE, HOWEVER, WE WERE ALSO EQUIPPED WITH A SINGLE VLF OMEGA UNIT. THE CAPT INDICATED A DESIRE TO OVERFLY IOW VOR TO ESTABLISH THE ACCURACY OF THE OMEGA UNIT. DURING OUR CLB ENRTE TO IOW ATC ISSUED A RADAR VECTOR WHICH TOOK US SLIGHTLY S OF J-10. SOME TIME LATER ATC ADVISED THAT WE WERE CLRED TO JOT AND GAVE US A FREQ CHANGE. I WAS UNSURE IF THE CAPT WOULD ACCEPT THIS CLRNC SINCE HE WOULD NOT BE ABLE TO UPDATE THE OMEGA OVER IOW VOR. I STARTED TO QUESTION HIM ON THIS WHEN I SAW HIM RESET THE COURSE ON THE HSI AND BEGIN UPDATING THE OMEGA. I THEREFORE ASSUMED THE CLRNC SATISFACTORY AND THEN PROCEEDED TO CONTACT CTR ON THE NEW FREQ. UPON CONTACT WITH CTR I RPTED THAT WE WERE PROCEEDING TO JOT. THE CAPT MEANWHILE HAD THE ACFT IN A LEFT TURN. I THEN BECAME OCCUPIED WITH OTHER COCKPIT DUTIES FOR A SHORT TIME. ATC THEN CALLED AND ASKED IF WE WERE PROCEEDING DIRECT JOT. I REPLIED THAT WE WERE. ONCE I MADE THE REPLY I NOTICED THAT WE WERE STILL TURNING LEFT AND WERE CONSIDERABLY BEYOND THE HDG REQUIRED FOR DIRECT JOT. APPARENTLY THE CAPT WAS STILL INTENT ON OVERFLYING IOW AND HAD FAILED TO HEAR THE PREVIOUS CLRNC TO JOT, HEARING NOT WHAT WAS SAID, BUT WHAT HE EXPECTED TO HEAR. THE CAPT THEN REALIZED THE SITUATION AND SPOKE WITH ATC DIRECTLY, SAYING THAT HE HAD MISUNDERSTOOD THE CLRNC. ATC THEN ADVISED THAT WE WERE GETTING CLOSE TO ANOTHER ACFT'S AIRSPACE. WE THEN TURNED IMMEDIATELY AND FLEW DIRECTLY TO JOT. ATC LATER ADVISED THAT THERE WAS 'NO PROB' WITH OUR COURSE DEV. OUR CLOSE PROX TO IOW WHEN WE WERE CLRED DIRECT TO JOT REQUIRED THE CAPT TO CHANGE COURSE 50 TO 60 DEGS IN ORDER TO PROCEED DIRECT TO IOW. THIS LARGE HDG CHANGE IN A SHORT TIME CAUSED OUR TRACK TO DEVIATE FROM OUR CLRED COURSE VERY QUICKLY. ATC SOON NOTICED THIS CHANGE AND INQUIRED. I UNDOUBTEDLY WOULD HAVE CAUGHT THE ERROR IN ANOTHER FEW SECONDS, ONCE I HAD COMPLETED THE TASK AT HAND. THIS ILLUSTRATES PERFECTLY HOW QUICKLY THINGS CAN GO WRONG AND DRIVES HOME THE NEED TO PROPERLY BALANCE THE TIME SPENT BTWN PERFORMING COCKPIT DUTIES AND MONITORING THE ACFT. THIS IS ALSO A GOOD EXAMPLE OF MISCOM BTWN COCKPIT CREW MEMBERS. I THOUGHT WE WERE ON THE SAME 'WAVELENGTH' WHEN WE OBVIOUSLY WEREN'T.

Data retrieved from NASA's ASRS site as of July 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.