What happened
The aircraft experienced simultaneous illumination of both generator warning lights alongside left and right fuel pressure indicators. The flight crew had initiated a precautionary return to the departure airport due to these electrical anomalies. While en route, the annunciator panel lights began to flicker intermittently.
As the aircraft approached the runway for landing, the crew selected the landing flaps, but the system failed to operate. The landing gear was lowered, and the indication showed three green lights; however, visual inspection confirmed that the nose gear had not fully extended. During the touchdown phase, the aircraft lost directional control and veered significantly to the left of the runway surface.
The investigation
Post-accident analysis focused on the cockpit configuration differences between the C-model and the A-model variants. The captain had extensive experience flying the C-model but this was his first flight in the A-model variant. A critical design difference exists in the placement of the auto ignition and engine start generator switches, which are positioned in reverse relative to the C-model.
Findings
The investigation determined that the captain likely confused the switch positions due to his familiarity with the C-model layout. He inadvertently selected the engine start function instead of engaging the auto ignition system. Because the aircraft was operating on battery power at that moment, this error caused the depletion of electrical energy and the subsequent failure of both generators. This loss of electrical power contributed to the flap and nose gear malfunctions and the resulting loss of directional control.
Safety message
Pilots transitioning between aircraft models with reversed switch configurations must exercise extreme caution during critical phases of flight, particularly when relying on battery power or managing complex electrical systems.