What happened
The flight began with the aircraft engaged in skydiving operations. After discharging the skydivers, the pilot shifted focus to achieving the maximum rate of descent to return to the departure point or find an alternate landing site. To facilitate this rapid descent, the engine power was maintained at idle.
During this phase of flight, the fuel tank currently in use ran dry. The pilot did not notice a loss of power immediately while the throttle was still at idle. It was only when the pilot applied throttle to level off the aircraft that the engine failure became apparent.
Upon realizing the engine had stopped, the pilot initiated a sequence to switch to the usable fuel tank and attempted to restart the engine. However, the altitude remaining at the time of the power loss was insufficient to complete these procedures successfully or to glide to a suitable airport. Consequently, the pilot executed a forced landing on a freeway off-ramp.
The investigation
The investigation focused on the operational sequence leading to the fuel exhaustion. Key factors identified included the pilot's concentration on maximizing the descent rate rather than monitoring fuel quantity during the power-off phase. The failure to switch fuel tanks before the active tank was depleted was a critical factor in the inability to continue powered flight.
Findings
The primary cause of the incident was fuel exhaustion due to the pilot's failure to monitor fuel quantity while operating with engine power at idle for an extended descent. Contributing factors included the insufficient altitude remaining to execute a successful restart or glide to an airport, and the decision to prioritize rate of descent over fuel management.
The aircraft sustained substantial damage during the forced landing on the freeway off-ramp. There were no fatalities reported among the occupants, though injuries may have occurred depending on the severity of the impact (specific injury counts not detailed in source narrative).
Safety message
Pilots operating skydiving aircraft should be aware that extended periods of idle power during rapid descents can lead to fuel exhaustion if tanks are not monitored closely. It is critical to switch fuel tanks proactively rather than reactively when power settings change significantly, especially when altitude is limited.