What happened
During a firefighting operation conducted in the vicinity of Tucson, Arizona, an aircraft experienced a critical malfunction involving its propulsion system. While operating at a low altitude, the crew observed that all four engines were losing power. In response to this sudden loss of thrust, the pilots initiated an emergency descent to perform a forced landing.
The aircraft subsequently crash landed in a remote, uninhabited area. Although the impact resulted in the aircraft being damaged beyond repair, both pilots escaped the wreckage without any injuries.
Findings
Investigations into the incident identified a failure within the fuel system and the ram air assembly as the primary drivers of the accident. Specifically, a baffle located within the air intake scoop became detached from the number four engine. This mechanical separation disrupted the necessary airflow to the carburetors for engines 1, 2, and 3. As a result of this-airflow disruption, the propellers transitioned to a high pitch setting, contributing to the simultaneous loss of power across the entire propulsion system.