Cessna last month was close to certifying a software update for the Citation Mustang’s G1000 avionics system after avionics maker Garmin in February uncovered a programming glitch. The problem is causing course deviation errors and a loss of some navigation cues on the map display when the pilot attempts to load a new arrival or departure procedure without deleting a previously loaded procedure. Cessna will certify the new software before delivering any more than the two it previously delivered.

Garmin described the error, which also affects WAAS-capable versions of the GNS 430/530W, as a nuisance for pilots but not a safety issue. For now, the avionics maker is telling pilots to avoid the error by removing an active arrival or departure procedure from the flight plan before adding a new arrival or departure procedure. Future software updates for G1000 and GNS 430/530W equipment will correct the glitch, Garmin said.

Mustang deliveries were scheduled to restart late last month.