NTSB Factual Report

HISTORY OF FLIGHT

On May 2, 2008, approximately 1630 Pacific daylight time, a Yakovlev Yak 52 airplane, N62813, was substantially damaged when it impacted terrain while maneuvering near the Green Mountain Airport (WA67), Vancouver, Washington. The commercial pilot and his passenger were killed. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight that departed from WA67 about five minutes prior to the time of the accident.

A witness located at WA67 reported observing the airplane depart the airport to the west and execute a 180-degree turn back towards the airport. The witness stated the airplane made a high-speed pass over the runway about 30 to 40 feet above ground level (agl) on an easterly heading and pitched upwards abruptly near the end of the runway into a steep climb out. During the steep climb out, the airplane was observed performing an "aileron roll to the right." At the completion of the roll, the airplane appeared to be in a level attitude when a slight movement was observed, "as if it hit turbulence." The airplane subsequently descended in a nose-low attitude, eventually descending below a tree line.

A second witness located about one half mile east of the runway reported observing the airplane over fly his position at an altitude below 200 feet agl. The witness stated that the engine sounded like it was running at a high power setting as the airplane rolled upside down to the right and remained upside down for a few seconds before it descended below a tree line in a nose low attitude. The witness added that from the time he saw and heard the airplane fly over until he lost site of it, the engine sounded the same with no sudden power changes.

A third and forth witness, located just east of the runway reported observing the airplane fly over head about 200 feet above ground level . The witnesses stated that the airplane rolled upside down and back upright before it descended below a tree line in a nose low attitude and that the engine was running like it was at full power until they heard the impact.

PERSONNEL INFORMATION

The pilot, age 66, held an airline transport pilot certificate with an airplane multi-engine land rating, a commercial pilot certificate with airplane single-engine land, airplane single-engine sea ratings and type ratings in multiple transport category aircraft. The pilot also possessed a mechanic certificate with airplane and power plant ratings. The pilot was issued a third-class airman medical certificate on December 2, 2007, with "must have available glasses for near vision, not valid for any class after" limitations stated. The pilot's logbook was not recovered during the investigation. The pilot reported on his most recent medical certificate application, that he had accumulated 20,000 total flight hours. The pilot's most recent flight review was completed on June 8, 2006.

AIRCRAFT INFORMATION

The 1980 experimental Yakovlev Yak 52 (serial number 800608) was a tandem seat, low wing, aerobatic, single-engine airplane. The airplane was powered by a 360-horsepower nine-cylinder Vedeneev M-14P radial engine, driving a two-bladed counter-clockwise rotating, constant speed wooden propeller. The aircraft maintenance records were not located during the investigation.

METEOROLOGICAL INFORMATION

A review of recorded data from the Portland International Airport (PDX) automated surface observation station, located about 7 miles southwest from the accident site, revealed at 1653, weather conditions were: wind from 100 degrees at 7 knots, visibility 10 statute miles, few clouds at 6,000 feet, broken cloud layer at 11,000 feet, overcast ceiling at 25,000 feet, temperature 20 degrees Celsius, dew point 6 degrees Celsius, and an altimeter setting of 30.05 inches of Mercury.

WRECKAGE AND IMPACT INFORMATION

Examination of the wreckage at the accident site by a Federal Aviation Administration inspector revealed that the airplane came to rest upright within a wooded area about one mile east of WA67. The inspector stated that ground scares were consistent with the airplane impacting in a nose low attitude. All flight control components were located at the accident site. According to a witness who located the wreckage, fuel was leaking from the left side of the airplane shortly after the accident.

The recovered wreckage was examined at the facilities of AvTech Services, Maple Valley, Washington by the NTSB investigator-in-charge. Examination of the airframe revealed that the fuselage was separated into two pieces and exhibited heavy deformation from the engine firewall aft to the rear of the cockpit. The right horizontal stabilizer, elevator, vertical stabilizer, and rudder were intact and undamaged. The left horizontal stabilizer and elevator were cut by recovery personnel to facilitate recovery.

The right wing was separated just inboard of the aileron and exhibited leading edge crushing from the wingtip about four feet inboard. The inboard portion of the right wing was cut by recovery personnel to facilitate wreckage recovery. The left wing was separated from the fuselage and buckled throughout with leading edge deformation. The outboard portion of the left wing was separated inboard of the aileron.

Flight control continuity was established from the cockpit to all of the primary flight controls. The aileron and elevator control torque tubes were separated in multiple areas. All of the fracture surfaces were found consistent with overload and impact damage except where cut by recovery personnel. The rudder control cables remained attached to the forward and aft sets of rudder pedals and were separated in multiple areas. All of the areas of separation were consistent with overload.

The left fuel tank was separated from the wing and was bulging outwards. The right wing fuel tank remained intact within the wing structure. Both the left and right fuel tanks were breeched. The center wing tank was not located. No anomalies were noted during the examination of the airframe.

Examination of the engine revealed that it remained attached to the airframe via the engine mount. The forward sparkplugs were removed from each cylinder with the exception of two that were damaged. Rotational continuity was established throughout the engine and valve train when the crankshaft was rotated by hand using the propeller assembly. Thumb compression was obtained on seven of the nine cylinders. Damage was observed to the two rocker arm push rods for the remaining two cylinders.

The carburetor was separated from the engine. The throttle arm moved freely by hand from stop to stop. The carburetor fuel screens were intact and free of debris. About two or three ounces of liquid that was consistent with fuel was removed from the carburetor. The airframe fuel filter was free of debris. About four ounces of liquid was removed from the unfiltered side of the filter and was brown/black in color. No anomalies were noted with the engine.

Two of the three propeller blades were separated from the propeller hub. One blade remained attached to the hub and was fractured and splintered about eight inches outboard from the hub. One of the two propeller blades that were separated was partially fractured about mid-span. The third propeller blade was not recovered.

MEDICAL AND PATHOLOGICAL INFORMATION

The Clark County Medical Examiner's office conducted an autopsy on the pilot on May 4, 2008. The medical examiner determined that the cause of death was "Multiple blunt force trauma."

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested. An unspecified amount of Diphenhydramine and Quinine were found in the urine.

NTSB Probable Cause

The pilot's failure to maintain an airspeed sufficient to avoid a stall during a low altitude aerobatic maneuver. Contributing to the accident was the low altitude at which the pilot initiated the maneuver.