Cessna 152 N757YM accident near Danbury, Connecticut

Probable cause

The flight instructor’s inadequate preflight fuel planning and oversight of the preflight inspection, which resulted in a total loss of engine power due to fuel exhaustion.

NTSB analysis

The airplane was fueled earlier in the day then flown on 3 separate flights totaling 3.1 hours. Before the accident flight, the student pilot used a fuel dipstick to check the fuel level in each tank but she did not recall the fuel quantity in either tank and the flight instructor did not verify the fuel quantity. After departure, with a reported 15 gallons of fuel on board, the student performed pattern work, airwork, and more traffic pattern work. After the 3rd go-around, while on the downwind leg abeam the landing spot, the flight instructor took over the controls to demonstrate a landing. After turning onto base leg, the engine began to lose power. He pitched then nose down and reported the engine started and for about 2 seconds before losing power completely. He noted there were 2 high towers near the end of the runway and turned toward a grass field behind him and performed a steep spiral to lose altitude. The airplane slowed, and he heard the stall warning horn. He moved the flap selector from 10° to 20° then braced for impact. The airplane impacted a shed and came to rest adjacent to a house.

Postaccident examination of the engine and its systems revealed no evidence of preimpact failure or malfunction. The airframe fuel strainer was found to contain about 1 ounce of fuel and the carburetor bowl was empty. The right wing contained about 1.7 gallons of fuel and the left fuel tank was empty.

The usable fuel capacity of the airplane was 24.5 gallons. The airplane was flown 5.3 hours since the fuel tanks were last filled. The published fuel consumption rate for the engine was listed as being between 5.8 gallons per hour (gph) and 9.5 gph depending on power settings used. Given the fuel capacity of the airplane and the amount of time the airplane was flown after being fueled, it is likely that the loss of engine power was a result of fuel exhaustion.

Text from the NTSB. Open the NTSB docket for ERA23LA191 for the full record.