History of Flight
On August 23, 2011, at approximately 1138 Pacific daylight time, a Cessna 150G, registration N2870S, crashed about 150 yards east of the southern grass landing strip at Cavanaugh Bay Airport, Coolin, Idaho. The owner-operated airplane was being flown under Title 14 Code of Federal Regulations Part 91. The private pilot sustained serious injuries, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and no flight plan was filed. The flight had originated from Chattaroy, Washington, around 0900.
Witnesses reported to a Federal Aviation Administration inspector that they observed the airplane approaching the grass strip. One witness stated that the left wing dipped, then the airplane pitched up to a high angle of attack and descended vertically; he lost sight of it behind trees but heard the engine developing high power until contact with trees and terrain.
The airport lies on the southeastern side of Priest Lake. The wreckage was found among a large grove of conifer trees, 150 yards east of the grass runway. The airplane rested on its nose, with wing leading edges parallel to the ground, and the tail buckled and skewed left of center. First responders noted fuel leaking and the pilot seriously injured with head, arm, and chest injuries.
The pilot reported that he had flown into the airstrip about 10 times over the last 10 years. The flight was recreational, and he made a normal approach to the southern runway, which is sloped; a landing to the south would be upslope. During approach, he estimated an 8- to 10-knot tailwind based on the water surface of Priest Lake. He also noted 100-foot-tall trees at the approach end that made the landing difficult. He could not recall the missed approach, go-around, or crash.
Personnel Information
The pilot, aged 85, held a private pilot certificate for airplane single-engine land issued December 18, 2003, and a third-class medical certificate issued June 16, 1994, with a limitation requiring glasses for near vision. He reported approximately 900 total flight hours, mostly in Cessna 172 series, with 30–40 hours in the accident model. His most recent flight review was on July 1, 2011, in the accident airplane.
Aircraft Information
The two-seat, high-wing, fixed landing gear airplane, serial number 15066770, was manufactured in 1967. It was equipped with an Alpha Systems angle of attack indicating system, with a gauge on the pilot's glare shield. The engine was a Lycoming O-320-E2D, 150-horsepower, with a McCauley fixed-pitch propeller, model TM7456. An FAA Form 337 documented an engine replacement on December 8, 1986, from the original Continental O-200 series (100 hp) to the Lycoming. The annual inspection was performed on November 17, 2010, at an airframe total time of 5,803 hours and engine time since major overhaul of 2,081 hours.
Wreckage and Impact Information
On September 14, 2011, the NTSB investigator-in-charge and a Cessna technical representative examined the wreckage at a facility in Deer Park, Washington. The wings had been separated from the fuselage for transportation. Control continuity was confirmed from cockpit to ailerons, elevator, and rudder, though multiple cables had been cut by the recovery crew. Flaps appeared retracted; the flap actuator was retracted. Elevator trim measured 1.44 inches; the Cessna representative stated that 1.45 inches is neutral. The stall warning horn was clear and sounded when air was passed through the reed.
Throttle cable was connected from cockpit to carburetor. The mixture cable was connected at the cockpit but severed at the carburetor mixture lever. The carburetor bowl was separated from the upper body; brass floats were mechanically damaged and crushed. The top spark plugs, Champion REM37BY, were removed. All gaps exceeded 0.016 inches, exhibited light gray coloration, and wear signatures consistent with normal operation per the Champion Check-a-Plug AV-27 card. The McCauley fixed-pitch propeller showed slight leading edge polishing and chordwise scratches on one blade; the other blade tip was bent forward 90 degrees with substantial polishing along the leading edge and face.
No preaccident mechanical failures or malfunctions were found that would have precluded normal operation.