On February 17, 2021, about 945 eastern standard time, a Cessna 150, N8428J, was substantially damaged when it was involved in an accident near Maryland Airport (2W5), Indian Head, Maryland. The flight instructor and pilot receiving instruction were uninjured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

According to the pilot receiving instruction, he was flying with his flight instructor from Potomac Airfield (VKX), Friendly, Maryland. to prepare for his initial flight instructor check ride. He added 10 gallons of fuel to the fuel tanks, conducted a preflight inspection, and rocked the wings to release any water that might have been trapped in the fuel bladders before draining the fuel tank sumps. The pilot receiving instruction noted no water from the wing sump fuel samples but water appeared in the fuel that was drained from the fuel strainer drain. After he drained “about half a tube” of water from the airplane’s belly, no further water was noted. About 90 minutes into the lesson and while pilot receiving instruction was performing a left chandelle maneuver, the engine “hiccupped” momentarily. The flight instructor and the pilot receiving instruction decided to climb to 4,000 ft and proceed about 10 miles northwest to 2W5 for a precautionary landing. The pilot receiving instruction reported that, while over 2W5, he descended the airplane in a circle over the airport. While abeam the runway numbers on a right downwind leg to runway 20, the airplane was still several hundred feet above the airport traffic pattern altitude. The pilot receiving instruction stated that the flight instructor took the flight controls and initiated an “aggressive” right-wing-low sideslip to lose altitude while keeping the throttle set to 1,400 rpm to ensure that the engine did not lose power. The flight instructor stated that the flaps were not extended during the sideslip because the airplane’s airspeed was “above the white arc.” When the airplane reached the midpoint of the runway at an indicated airspeed of 100 knots, the flight instructor executed a go-around maneuver. During the maneuver, after the airplane climbed about 300 to 400 ft, the engine stopped producing power, and the propeller windmilled momentarily before stopping. With inadequate time to perform remedial actions, the flight instructor executed a forced landing into the trees. The airplane impacted trees and descended nose down to the ground, substantially damaging the empennage and both wings.

Postaccident examination of the airframe revealed corrosion around the exterior of the fuel filler necks. White sediment was found in the fuel samples taken from the left and right fuel tanks. Additionally, water was recovered from the fuel sample taken from the left-wing fuel tank and the fuel strainer assembly. The fuel strainer assembly bowl exhibited white chalky corrosion, and the fuel strainer standpipe and sump spring tube were covered in white deposits. The fuel strainer screen exterior was obscured by white chalky deposits inside the screen. The carburetor fuel inlet screen was removed, and the threads in the carburetor body exhibited white chalky corrosion. The sediment was examined using an x-ray fluorescence alloy analyzer and was found to be consistent with soil. Postaccident examination of the engine revealed no anomalies; the engine was started, and the engine operated as expected during the run-up.

Federal Aviation Administration Advisory Circular 20-125, “Water in Aviation Fuels,” stated that “an important part of the preflight inspection is to drain aircraft fuel tanks sumps, reservoirs, gascolators, filters and other fuel system drains to assure that the fuel supply is free of water.” The advisory circular also stated the following:

Aircraft fuel tanks are constructed with sumps to trap water. Since it is practically impossible to drain all water from the tanks through the fuel lines, the fuel tank sumps should be regularly drained in order to remove all water from the system. It may be necessary to gently rock the wings of some aircraft while draining the sumps in order to completely drain all the water.