Incident Overview
A Fairchild C-119G airtanker was dispatched to a wildfire approximately six miles west of Castle Crags State Park, California at 17:05. The aircraft departed the Siskiyou County Airport (SIY) shortly thereafter. Another airtanker of the same type (N48076), a leadplane, and an air attack aircraft arrived at the fire simultaneously. Two additional airtankers followed shortly.
Pre-Drop Coordination
The leadplane identified the target, approach, and departure routes. It indicated the target elevation was 4,500 feet and that the ridge on final approach should be crossed at 6,600 feet. The leadplane advised no wind, good visibility, and no turbulence except a "1.5g bump" when crossing the head of the fire.
First Airtanker Drop
The leadplane directed one of the C-119 airtankers to drop first. That airtanker aborted its first run due to excess speed. On the second pass, it crossed the ridge at a different point, allowing a longer final approach. The drop was successful. The run was made through a saddle, then down a creek to the fire approximately two miles downstream, with a planned exit downstream into a larger canyon.
Mishap Airtanker Drop
The leadplane then directed the mishap C-119G airtanker to drop next. It used the same approach as the first airtanker. The mishap airtanker reached the uphill side of the fire when the crew reported trouble maintaining proper speed. The pilot dropped the retardant on the fire.
Structural Failure and Impact
At about the time the pilot dropped the retardant, a structural failure occurred. The right wing separated from the airframe along with the tip of the left wing and the tail booms. The fuselage, with both engines and most of the left wing attached, encountered terrain impact and burned as a unit.