On June 11, 2022, about 1500 eastern daylight time, an experimental amateur-built A Plane, N51324, was substantially damaged when it was involved in an accident near Middleboro, Massachusetts. The private pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.   The pilot stated that earlier that day he drained each wing fuel tank, added 6 gallons of fuel/oil equally divided into each wing fuel tank, and checked the vented fuel caps. He departed on an uneventful 15-minute flight and, after landing, added the remaining 2 gallons of fuel/oil. As part of his preflight check he did not find any water in the fuel tanks or from the lowest part of the fuel system, and reported a normal rpm drop during the check of the dual ignition system as part of his run-up. Prior to departure he performed a full-throttle pass on the runway with no discrepancies noted. He then taxied back to the departure end of the runway where he initiated the takeoff, noting that the engine rpm was at 6,300. After becoming airborne and at the start of a left turn, the engine began to “die out,” which he described as the engine rpm dropping to 4,000, increasing to 5,000, then decreasing to 3,000 before the engine completely lost power. At that time the airplane was 50 ft above the treetops. He glided but when the flight was 20 ft above the treetops the airplane dropped consistent with a stall/mush and descended into a tree. The airplane descended to the ground in a near-vertical, nose-low attitude that resulted in substantial damage to the right wing. He shut off the fuel before getting out of the airplane.

Following recovery of the airplane, a sample of fuel taken from one of the fuel tanks contained drops of water, and the carburetor bowl was empty. There were no obstructions of the fuel supply system from each wing fuel tank to the fuel shut-off valve, which was installed about 1 ft from the in-line fuel filter. After installing a different propeller, the pilot plumbed a temporary fuel supply into the fuel filter inlet. Using the same fuel that was in the airplane’s fuel tanks at the time of the accident, the engine was started and ran using the manifold-driven pneumatic fuel pump to between 4,000 and 4,500 rpm (safety concerns prevented full-throttle application). Although a check of the dual ignition system was not performed during the postaccident engine run, the pilot reported no discrepancies.

The temperature and dewpoint 8 minutes before the accident at an airport about 6 nm east-northeast from the accident site were 75°F and 50°F, respectively. A review of Federal Aviation Administration Special Airworthiness Information Bulletin (SAIB) CE-09-35, Carburetor Ice Prevention, revealed the environmental conditions about the time of the accident were favorable for serious icing at glide power.