Amateur-built VANS RV9A N708JE accident near Kingston, Oklahoma

Probable cause

The pilot’s continuation of a banked turn following the loss of engine power, which resulted in his failure to maintain adequate airspeed and the airplane exceeding its critical angle of attack and entering an accelerated stall at low altitude. Contributing to the accident was the loss of engine power due to carburetor icing as a result of the airplane's degraded carburetor heat system.

NTSB analysis

The student pilot contacted a friend who was in a fishing boat and told him he was going to fly over the lake. The friend then saw the airplane circle over his fishing boat, which was a prearranged signal by the student pilot to notify the friend to drive his fishing boat towards a better fishing spot. The airplane was flying in a descending left turn and impacted the water and sank. The airplane was located the following day and was recovered to the shore. Although damage was sustained during the recovery phase, an examination of the airframe did not find any preimpact anomalies. The circumstances of the accident are consistent with an accelerated stall while the airplane maneuvering at low altitude.

An examination of the engine found that continuity to the engine controls was established with the exception of the carburetor heat gate cable. An examination of the carburetor heat gate cable did not find any deformation consistent with the set screw being installed properly at the time of the impact. A family member reported that the pilot previously had the carburetor heat repaired, but no logbook entry could be found to tell when and by whom the carburetor heat was repaired.

A review of the carburetor icing probability chart found that, at the time of the accident, the airplane operated in an area with the potential for serious icing at glide power. During the circling maneuver, it is likely that the pilot was operating the airplane a reduced power setting, which resulted in the formation of carburetor icing and led to a loss of engine power. However, once power was lost, the pilot continued in a bank turn, which resulted in the accelerated stall, rather than maintaining level flight.

Text from the NTSB. Open the NTSB docket for CEN15FA127 for the full record.