What happened
The aircraft was engaged in a mission to drop smokejumpers at the Dusenbury fire incident located within the South Warner Wilderness area of the Modoc National Forest. During the descent over the fire, conditions were smooth. The mission involved dropping 9 smokejumpers at 8,500 feet mean sea level (msl) across five passes, followed by four additional passes to drop cargo.
Following the completion of jump and cargo operations, the aircraft performed 360-degree circuits to gain altitude for the return flight to Redding. At the time of the incident, the "fasten seatbelt" sign had been turned off to allow cabin crewmembers (spotters) to secure the cabin.
As the aircraft crossed a ridge line at 9,000 feet msl (800 feet above ground level), it encountered sudden wind shear, specifically a downdraft, before returning to smooth air. During this turbulence, one spotter struck his helmet against the ceiling but was not injured. A second spotter, located in the mid-cabin area, reported sustaining a broken leg. The pilot subsequently diverted the flight to Alturas.
Safety message
Following the event, the pilot submitted a Safecon Aviation Safety Communique and provided several recommendations:
- Re-emphasize cabin safety awareness to all flight crews.
- Maintain awareness of the potential for hidden turbulence when operating over mountainous terrain.
- Ensure personnel remain in stable air while moving about the cabin or securing cargo after drop missions.
- Ensure all personnel are seated with seatbelts fastened whenever turbulence is anticipated.