Accident Overview
On September 28, 2021, at 1453 eastern daylight time, a Cessna 150M, registration N4100V, was substantially damaged in an accident near Hobe Sound, Florida. The pilot sustained serious injuries. The flight was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
Flight Details
According to the pilot, a preflight inspection revealed no anomalies. He flew 9 nautical miles from Valkaria Airport (X59) to Sebastian Airport (X26) for fuel. After refueling, the airplane departed X26 for a flight to Witham Field Airport (SUA) in Stuart, Florida. During the initial climb, the pilot noted an unusually high angle of attack and lower than expected climb performance, which he attributed to heat and full fuel. The pilot recalled monitoring the gauges due to concern about performance. Approximately 48 miles from X26, he determined the airplane was losing performance and would not reach an airport, initiating a forced landing in an open field. During the landing flare, the airplane stalled and impacted the ground, coming to rest upright with substantial damage to the wings and fuselage.
Postaccident Examination
Examination of the accident site revealed the right wing partially separated at its root, crushed and bent upward and aft outboard of the wing strut. The left wing was damaged near its root, and both forward cabin door pillars were crushed. The aft fuselage was fractured and partially separated just aft of the rear window. Fuel sampled from the right wing tank was blue and cloudy; no fuel was present in the left wing. The fuel selector was in the "ON" position. The elevator trim tab actuator measured 1 inch, corresponding to a tab position of 10° trailing edge down (airplane nose up).
The engine was mostly undamaged. One propeller blade was bent 90° midspan, and the other was bent and twisted about 10 inches from the tip. No leading-edge gouges or chordwise scratches were observed. Top spark plugs had light gray electrodes, appearing "worn-normal" per the Champion check-a-plug chart. Thumb compression and suction were confirmed on all cylinders; both magnetos produced sparks. Fuel from the strainer was blue and tested negative for water.
The carburetor had fractured from the intake manifold. Throttle, mixture, and carburetor heat control cables remained attached. The fuel inlet screen was unobstructed; the bowl was dry with trace debris; the metal float and needle valve/seat were intact.
Weather and Performance Information
At 1458, weather at SUA (8 nautical miles north of the accident site, elevation 18 ft) reported temperature 29°C, dew point 16°C, and scattered clouds at 3,500 ft. These temperatures fell within the "serious icing at glide power" portion of the FAA's carburetor icing probability chart.
According to the airplane's performance section, at maximum gross weight and 30°C, expected climb performance was 625 ft/min at sea level at 68 knots, and 435 ft/min at 4,000 ft at 65 knots.
Maintenance History
The engine had 4,683 hours total time, 1,167 hours since overhaul. The most recent inspection before the accident was a 100-hour inspection on June 8, 2021. Cylinder compression test results showed decreases in three cylinders (17, 10, and 8 psi) since the previous inspection; one cylinder increased by 6 psi. One cylinder's compression had decreased during two consecutive inspections. Cylinders No. 1 and 4 had the lowest values (55 psi). A service bulletin from the engine manufacturer indicated acceptable compression values vary and are determined at the time of test. No conditions related to low compression (excessive oil consumption, abnormal oil appearance, or high crankcase pressure) were noted in maintenance records from the previous 3 years.