Small Transport; Low Wing; 2 Recip Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Multiengine
Distraction; Situational Awareness; Workload; Troubleshooting
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Returned To Clearance
Human Factors; Procedure
IFR flight plan to FAI. Level at 7000; IMC; Autopilot engaged; Cleared down to 6000 and cleared direct HOSAN (unfamiliar fix). Selected Vertical Speed/Down on autopilot; began stable descent. Broke out into excellent VMC conditions (large hole; visibility estimated >20 nm; ground clearly visible below; familiar terrain). Relaxed when VMC conditions appeared; and started trying to find HOSAN in GPS and on approach charts (expected to find it easily). Unable to find HOSAN fix in GPS; found it on approach chart; still unable to find in GPS. Glancing out window showed no hazard from terrain. Head-down; programming GPS; looked up and noticed low altitude. Immediately disengaged autopilot; and climbed back to altitude in VMC. Lulled into sense of complacency by good VMC conditions and clear view of ground below; as well as familiar local terrain. Got lost in GPS programming. Did not ask for clearance to a familiar fix; which would be easier to find. Perhaps we should develop a rule of thumb (to help pilots in dealing with automated systems); and train them to recognize when to use this rule of thumb. Perhaps something like this: 'When programming an automated system; try it one time. If that attempt is unsuccessful; then try one more time. If the second attempt at programming fails; then drop back to the next lower level of automation.' A rule of thumb like this could help reduce head-down time in dealing with automated aircraft/systems. Scenario-based training is probably a good way to introduce this rule of thumb. If ATC only uses familiar; major fixes (initial approach fix; final approach fix; etc) in routing instructions; then pilots will spend less time searching for fixes. This would also reduce head-down time in the cockpit.
Air taxi pilot descending into Fairbanks reported becoming distracted while attempting to find and enter the fix he was cleared direct to and descended below his assigned altitude.