Accident Details
On August 20, 2023, at approximately 0800 central daylight time, a Pietenpol Aircamper, registration N929DH, was substantially damaged during an accident near Hanover, Illinois. The pilot sustained minor injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Account
The pilot reported fueling the airplane with nonethanol automotive gasoline (MOGAS) to a full capacity of 11 gallons prior to departure from Monticello Regional Airport (MXO), Monticello, Iowa. The intended destination was Poplar Grove Airport (C77), Poplar Grove, Illinois. After about 45 minutes of flight, the engine began to lose power. The pilot initiated a forced landing to a hayfield, but the airplane impacted terrain in a cornfield short of the intended landing area. The accident resulted in substantial damage to both wings and the fuselage.
Postaccident Examination
Postaccident inspection of the fuel system revealed that the fuel cap was loosely installed and the sight glass indicated the fuel tank was nearly full. The fuel shutoff valve was found in the OFF position; the pilot reported shutting off the fuel after the forced landing. Fuel samples taken from the gascolator contained unidentified white particulate, with no water detected. The carburetor bowl held a small amount of fuel, and approximately 3 ounces of fuel was found in the intake pipe after carburetor removal. The carburetor was disassembled and found to be unremarkable, aside from slight corrosion on the gas adjustment valve needle.
Engine Examination
The airplane’s modified Ford Model A engine remained intact. The throttle cable was disconnected at the carburetor, with the cable pinch bolt still located in the throttle arm. Thumb compression was obtained on all four cylinders, the spark plugs were unremarkable, and a test of the top magneto produced spark on all leads. No mechanical malfunctions or failures that would have precluded normal operation were identified.
Carburetor Icing Potential
The carburetor icing probability chart from FAA Special Airworthiness Information Bulletin CE-09-35, Carburetor Icing Prevention, indicated a potential for carburetor icing at glide and cruise power given the temperature and dew point reported at the time of the accident.