NTSB Identification: WPR12FA274
14 CFR Part 91: General Aviation
Accident occurred Saturday, June 23, 2012 in Veneta, OR
Probable Cause Approval Date: 12/02/2013
Aircraft: CESSNA 172, registration: N5781A
Injuries: 4 Fatal.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

Local witnesses reported that the airplane took off from the airport; however, shortly after takeoff, the sound of the engine stopped. One witness reported that when he saw the accident airplane fly over 100-foot-tall trees north of him at an altitude of about 200 feet above ground level, the engine sounded normal. However, when he looked away from the airplane momentarily, he heard the engine stop. He immediately looked back and saw the airplane descend into the 100-foot tall trees.

A portable electronic device was located in the wreckage, and it contained a 23-second video that was recorded during the accident flight and ended just before the airplane impacted the trees. Review of the video revealed that it began as the airplane initiated the takeoff roll on the grass runway. The video briefly captured the engine tachometer gauge, which displayed 2,300 rpm. Throughout the video, the engine sound was consistent and did not increase or decrease. During the final 8 seconds of the video, after the airplane became airborne, a sound similar to a stall warning horn began and was heard until the end of the recording. During the last 4 seconds of the video, only the sky and the airplane’s propeller were visible.

Postaccident examination of the airframe and engine and a postaccident engine run revealed no evidence of any preimpact mechanical malfunction or failure that would have precluded normal operation. The throttle control was found in the idle position and was bent downward. Given the idle position of the throttle and downward bend, it is likely that the pilot reduced power before the airplane collided with the trees. The sound of the stall warning horn in the video suggests that the airplane was traveling at a slow airspeed immediately after takeoff and most likely continued in this state throughout the climb. Although witnesses reported hearing the engine lose power, it is possible that the witnesses heard the reduction of engine power from a high power setting to an idle power setting before the airplane’s impact with trees and attributed the sound to a loss of engine power.

Toxicology tests on the pilot were found positive for metabolites of marijuana within the pilot’s blood and lung tissue. Most behavioral and physiological effects return to baseline levels within 3-5 hours after drug use, although some residual effects in specific behaviors have been demonstrated up to 24 hours, such as complex divided attention tasks. Psychomotor impairment can persist after the perceived high has dissipated. Although the pilot’s use of marijuana may have affected his ability to successfully manage this flight, use likely occurred more than 5 hours before the accident, and the exact degree of impairments in cognition, judgment, and motor function could not be determined.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot’s failure to maintain adequate airspeed and altitude to clear trees during the initial climb after takeoff.

Full narrative available

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