Baron 58/58TC
Flight Crew Multiengine; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 88; Flight Crew Total 13861; Flight Crew Type 7
Human-Machine Interface; Distraction; Fatigue
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance
Human Factors; Aircraft
I was the overseeing pilot on an IFR flight plan filed in my name. The flying pilot was a private pilot; multi engine rated; non IFR pilot. We filed IFR in case an approach would be needed at DRT. I was programming the GPS while we were cruising at an assigned altitude of 5;000 FT. The other pilot was flying with the autopilot engaged; (I thought). Suddenly he noticed altitude was about 5;400 FT and started correcting. About then Laughlin called and asked to verify we were still at 5;000 FT. He said we were correcting from 5;500 FT back to 5;000 FT. I had realized then that he had been following what I was doing on the GPS instead of watching the airplane closer. In effect we were both heads down on the GPS; while the aircraft drifted up. I have to attribute this partly to distraction from automation; partly to a lack of training on part of the crew in dividing responsibilities; partly to being too focused to one thing instead of dividing attention between programming and supervision of aircraft/other crew; and partly to diminished [alertness due to] fatigue. My wife had been getting sick the night before; and I had gotten up several times in the night; breaking sleep. I didn't feel that bad when I arrived at the airport in the morning; however I did notice on the first leg I had frequent yawning and thought processes seemed slow; etc. That's when I knew I was more tired than I had realized.
A BE58 crew failed to maintain altitude awareness while programming their GPS and the aircraft gradually climbed 500 FT above their cleared altitude.