History of Flight
On September 8, 2019, a Cessna 140 airplane, N73000, was involved in an accident near Lakeview, South Dakota. The student pilot and a passenger sustained fatal injuries. The flight was conducted under 14 CFR Part 91 as an aerial observation mission. According to family members, the purpose was to fly over the Rosebud Indian Reservation to inspect water towers on farms. The pilot would fly low over the towers to check water levels and report to farmers. It was unclear whether he was compensated. The departure time from the pilot's private airstrip was unknown. After several hours without contact, family members reported the airplane missing. The wreckage was located at about 0800 central daylight time on September 9, 2019.
Pilot Information
The pilot held a student pilot certificate with a limitation prohibiting carrying passengers, as per 14 CFR 61.89. The pilot's logbook showed flight time starting in August 2007, with the last logged flight in November 2015. He had a solo flight endorsement for a Cessna 150 dated October 29, 2015, which expired in July 2016. No solo endorsement for the Cessna 140 was found. A flight instructor who provided the initial solo endorsement described the pilot as a "safe pilot" but noted he flew with his son despite knowing it was prohibited. The pilot was initially taught by his grandfather, who was not a certificated pilot.
Aircraft Information
The airplane was modified to use automotive fuel (MOGAS) per FAA supplemental type certificates. It was not equipped with a carburetor temperature system or stall warning indicator, which were not required. Maintenance records showed no uncorrected mechanical discrepancies.
Meteorological Information
Weather data from Valentine, Nebraska, between 1652 and 2152 indicated temperatures of 16–19°C and dew points of 11–12°C. According to the FAA's carburetor icing probability graph, these conditions suggested a likelihood of serious icing at cruise or glide power settings.
Wreckage and Impact Information
The wreckage was located 825 ft northwest of the approach end of runway 17 at the pilot's private airstrip. The airplane came to rest on a heading of 24° at an elevation of 2,910 ft. Impact damage was consistent with a near-vertical, nose-down, left-wing-low attitude. Both wings, fuselage, and empennage sustained substantial damage. Flaps were extended at impact based on witness marks. The position of the carburetor heat control could not be determined due to impact damage. Fuel tanks were breached; a small amount of yellow fuel with debris was recovered. The propeller remained attached, with one blade straight and burnished, and the other bent aft without rotational signatures. No preimpact mechanical malfunctions were found.
Medical and Pathological Information
An autopsy attributed the pilot's cause of death to multiple blunt force injuries. Toxicology tests for carbon monoxide and ethanol were negative.
Organizational and Management Information
FAA Special Airworthiness Information Bulletin CE-09-35 addresses carburetor icing prevention. No information specific to MOGAS and carburetor icing has been published by the FAA.