ERA23LA297

The pilot reported that while taxiing before the flight, the engine had “skipped,” but normal power was regained during the run-up, so he decided to take off. The pilot reported that during the initial climb, the engine sustained a partial loss of power. He reported that, after the partial loss of power, he became fixated on the throttle and mixture and keeping the wings level. Subsequently, he realized he had traveled too far down the runway to abort the takeoff. He reduced the pitch attitude, navigated towards an open grassy area between trees, and lowered flaps to 40°. During the touchdown, the left wing abruptly dropped and impacted the ground and the airplane nosed over during the roll out. The fuselage, wings, and empennage sustained substantial damage. Multiple witnesses described that during the taxi and takeoff, the engine was running rough and skipping, and that the airplane struggled to gain altitude. Airport surveillance video captured most of the takeoff and initial climb. The video was consistent with the witness reports that the airplane struggled to climb throughout the entirety of the takeoff and initial climb, before disappearing out of view. Postaccident examination of the engine revealed that the No. 1 cylinder exhaust valve was stuck. There were no other anomalies observed with the airplane or engine. The pilot reported that in the few days preceding the accident, he had experienced multiple partial losses of engine power. He changed the spark plugs the day before the accident and the accident flight was the first flight after that maintenance. It is likely that the repeated engine skipping and partial losses of power the pilot experienced were evidence of a sticking valve, which ultimately became stuck during the accident flight. Had the pilot decided to allow a mechanic to examine the repeated engine issues more thoroughly, the stuck/sticking valve may have been properly diagnosed. Further contributing to the outcome was the pilot’s continuation of the takeoff roll and initial climb despite the opportunity to abort the takeoff and land on the remaining runway surface.

On July 12, 2023, about 1335 eastern daylight time, a Cessna 150L airplane, N16071, was substantially damaged when it was involved in an accident at the Elbert County Airport (EBA), Elberton, Georgia. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that during the engine start the engine “skipped” a few times. He then taxied to runway 11 at EBA and performed a run-up, which he described as “normal.” The pilot applied full power for takeoff, and when the airplane became airborne the engine exhibited “a couple of quick power surges” and then a steady partial loss of power. He recalled seeing an engine speed of 2,100 rpm and that he became “fixated” on the throttle, mixture, and keeping the wings level. During the initial climb, he realized he had traveled too far down the runway to abort the takeoff. Subsequently, he reduced pitch, navigated towards an open grassy area between trees, and lowered flaps to 40°. During the touchdown, the left wing abruptly dropped and impacted the ground, and the airplane nosed over during the roll out. The fuselage, wings, and empennage sustained substantial damage. Three witnesses at the airport heard and observed portions of the pilot’s taxi, run-up, and takeoff. The witnesses reported that during the pilot’s taxi the engine was skipping and running rough and continued to run rough during the takeoff. They described that during the initial climb, while the airplane was over the runway, the airplane could not gain altitude and eventually descended out of view towards trees and terrain. Airport surveillance video captured most of the takeoff and initial climb (the video did not capture sound). The airplane’s first rotation attempt occurred about 2,300 ft from the beginning of runway 31 (total length 5,004 ft). About 300 ft further down the runway, the airplane becomame airborne, but remained near ground effect and did not climb while flying over most of the remaining runway surface. After the airplane flew over the remaining runway surface, it again attempted to climb, and the airplane gained altitude for a few seconds, but descended in a left turn towards terrain and trees before it exited the camera’s view. The pilot reported that on July 8th, 2024, he had experienced a partial loss of power for about 4-5 seconds during flight, with the engine returning to normal power, and no further anomalies were observed. On July 11th, 2024, he completed a two-and-a-half-hour flight and refueled the airplane, with the engine performing normally. After refueling, the engine began to run rough and, as a result, the pilot changed the spark plugs and the engine operation returned to normal. The accident flight was the first flight after he changed the spark plugs. Postaccident examination of the airplane found that about 15 gallons of fuel remained on board. The engine examination revealed no anomalies with the fuel system, sparkplugs, or carburetor. The engine’s crankshaft could be rotated by hand. Crankshaft and camshaft continuity was confirmed, and all piston valves operated normally, with exception to the No. 1 cylinder exhaust valve. The valve was stuck and did not move despite the remainder of the valves operating normally. The airplane’s maintenance records documented that the most recent 100-hour inspection of the engine was completed August 2, 2022. The engine had accumulated 16.5 hours since this inspection. The engine was last overhauled on December 17, 1990, and it had accumulated 1,591 hours since this overhaul.