Cessna 208B Caravan, Oak Glen, Calif., March 28, 2006–The NTSB said the Caravan stall-spin crash that killed the two pilots was caused by the pilot’s continued flight into IMC and his subsequent failure to maintain adequate airspeed.
Cessna was operating the Caravan–flown by a company sales pilot and a regional sales distributor–on a sales demonstration tour. One of the pilots received an abbreviated weather briefing, which included an airmet for occasional moderate rime ice, for the flight from Thermal to Ontario, Calif. The pilot filed an IFR flight plan for the mountainous route where the minimum en route altitude was above the predicted icing level. The flight plan was not activated, and the pilots told a Tracon controller that they would fly through Banning Pass and activate the flight plan on the other side. The investigation determined that the flight was likely in at least intermittent, if not mostly solid, IMC in the pass. As the flight approached the other end of the pass, the controller advised that the radar showed they were heading into rising terrain. One of the pilots responded, “We’re maneuvering away from the terrain right now.” Then radar contact was lost.