Small Transport; Low Wing; 2 Turboprop Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Flight Crew Last 90 Days 50; Flight Crew Total 6780; Flight Crew Type 320
Distraction; Workload
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Clearance
Aircraft Equipment Problem Dissipated; Flight Crew Returned To Clearance; Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Aircraft
I was on a flight from to SLC. During my assent to my final cruising altitude; both of my GPSs stopped working. I diverted my attention to reacquiring the satellites. While rebooting the GPS radio; I inadvertently passed through my assigned altitude of 15;000 FT by 500 FT. I immediately turned off the autopilot and descended back to the altitude assigned. Because of a failure of both of my GPSs; I let my attention be diverted too much so that I lost my scan.
The reporter stated that he is not certain; but thought that maybe this issue was aircraft equipment related because it occurred two days in a row. One of the GPS receivers took about 15 minutes to come back online. ATC did not have any outrage reports for either day but his flight tracks were near both a MOA and Restricted area so the military had operations in that area both days. If actual interference existed; he cannot says.
While flying to SLC a light twin aircraft lost reception on both GPS receivers and while resetting them climbed through his assigned 15;000 FT altitude.