Flight History
On July 20, 2015, at approximately 12:42 Japan Standard Time, a privately owned Cessna 172P, registration JA4005, crashed shortly after takeoff from the Betsukai Flight Park Temporary Airfield in Betsukai-cho, Notsuke-gun, Hokkaido. The flight was intended as a pleasure flight to Obihiro Airport. The pilot occupied the right pilot seat, with passenger A in the left pilot seat, and passengers B and C in the rear seats.
The pilot planned a short-field takeoff from the grass runway, using the 560-meter-long Runway 14 and an additional 140-meter grass area in front of the runway threshold. The pilot commenced the takeoff with flaps set at 10 degrees and maximum power. The nosewheel was raised at an airspeed of about 20 to 30 knots, and the aircraft rotated at approximately 55 knots, lifting off about 300 meters before the runway end.
Immediately after liftoff, the stall warning horn began to sound. The pilot believed the warning stopped during the initial climb but continued climbing to clear obstacles. After the aircraft reached an altitude the pilot considered sufficient to clear a nearby windbreak forest, he secured the power knob and reached for an aeronautical chart in the right door pocket. While doing so, the edge of the chart struck the flap lever, retracting the flaps fully. The pilot then felt the aircraft suddenly stop climbing and enter a stall. The aircraft became unstable and crashed.
A witness, the airfield manager, observed the takeoff from about 50 meters left of the runway. After liftoff, the aircraft's altitude dropped slightly, then it pitched up sharply and ascended. It then veered left in an unstable condition, appearing to stall, and crashed in a meadow about 65 meters ahead of the witness, rolling onto its left side.
Global Positioning System (GPS) data recorded the takeoff roll beginning at about 12:41:30. The aircraft climbed to approximately 10 meters above ground level at an average ground speed of about 40 knots at 12:42:02, then descended, reaching ground level at 12:42:09.
Passenger A, who had limited experience in this aircraft type, was not monitoring the flight instruments and looked straight ahead, unaware of the stall situation. Passenger B reported hearing a continuous stall warning beeping after liftoff for about 5 to 6 seconds before the crash, noting a high pitch angle but insufficient climb performance. Passenger C similarly heard the stall warning continue after lift-off and observed the aircraft crash from an estimated altitude of 10 meters while rolling left.
The witness and several airfield personnel extinguished a fire that had broken out in the engine and rescued the occupants. Passenger C had evacuated but returned to assist the two in the pilot seats. The pilot was transported to a hospital by air ambulance; the three passengers by ground ambulance.
Injuries and Damage
The pilot, passenger A, and passenger B suffered serious injuries including bone fractures. Passenger C sustained minor injuries such as bruises. The aircraft was destroyed. Damage included upward deformation of both wings near the tips, broken nose and right main landing gear, broken and stuck flight controls, a severed engine primer line, and partial burning of the engine cowling.
Aircraft and Pilot Information
The aircraft was a Cessna 172P, serial number 17276205, manufactured on August 24, 1984, with a valid certificate of airworthiness. At the time of the accident, its estimated weight was 2,353 pounds, and its center of gravity was 45.3 inches aft of the reference datum, both within allowable limits (maximum takeoff weight 2,400 pounds; center of gravity range 39.0–47.3 inches).
The pilot, aged 74, held a private pilot certificate for single-engine and multi-engine land aircraft, with a specific pilot competence review restriction valid until November 13, 2015. His Class 2 aviation medical certificate was valid until March 13, 2016. Total flight time was 1,281 hours, including 800 hours on the Cessna 172 type, with 6 hours 30 minutes in the last 30 days.
Additional Information
Meteorological conditions at the airfield at 12:30 were clear skies, wind from the southwest at 6 to 11 knots, good visibility, and an outside temperature of 29°C. The accident site was a temporary grass airfield with a 560-meter-long by 24-meter-wide runway at an elevation of 407 feet. The aircraft came to rest on a meadow about 10 meters left of the runway edge, approximately 50 meters before the runway end, facing west opposite the takeoff direction, with flaps nearly fully retracted. A windbreak forest approximately 15 meters high was located about 400 meters from the runway end in the takeoff direction.
The flight manual stipulates that for short-field takeoffs with 10-degree flaps, the flaps should remain down until all obstacles are cleared and a safe retraction speed of 60 knots indicated airspeed is reached. The manual also provides takeoff performance data; under conditions similar to the accident (weight 2,400 pounds, pressure altitude 500 feet, no headwind, temperature 30°C, dry grass runway), the calculated ground roll was about 1,200 feet (366 meters) and total distance to clear a 50-foot obstacle was about 2,190 feet (668 meters).