N757YM

HISTORY OF FLIGHTOn April 10, 2023, about 1759 eastern daylight time, a Cessna 152, N757YM, was substantially damaged when it was involved in an accident near Danbury, Connecticut. The flight instructor and student pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

The student reported she performed weight and balance calculations, which reflected that there were 15 gallons of fuel on board. The flight instructor later reported he used a rate of 5 gallons-per-hour for fuel consumption calculations, or about 3 hours of fuel remaining, but that did not consider the fuel consumed for engine start, taxi, or takeoff. The student stated that she performed a preflight inspection that included a check of the fuel tanks using a dipstick, though she could not recall the value or reading in either tank. Her flight instructor indicated there was enough for the intended flight though he stated that he did not check the fuel tanks, and he could not recall either fuel gauge reading at engine start. The student performed an engine run-up before departure, which included a check of the magnetos and carburetor heat, both of which were operative. All instruments were working, and the flight instructor had her check the fuel gauges, but he did not recall her telling him anything about them.

According to ADS-B data, the flight departed from runway 26 about 1601, and the flight instructor stated that after takeoff they remained in the airport traffic pattern and performed a go-around, and a normal landing. They departed the airport traffic pattern to practice airwork, then returned to the airport to do more pattern work. After the 3rd go-around, while on the downwind leg abeam the landing spot, he took over control of the airplane to demonstrate a landing and turned onto the base leg of the airport traffic pattern. While flying at 65 knots between 800 and 900 ft mean sea level, the engine began “sputtering.” He pitched down and reported the engine started and only ran for about 2 seconds, then it lost all power. He looked at runway 26, and noted there were 2 high towers near the end of the runway and remembered a grass field behind him and turned to fly towards it. He 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° and braced for impact. The student reported the airplane impacted a shed. Both pilots reported an EMT told them they smelled of fuel after the accident. AIRCRAFT INFORMATIONThe airplane was modified in accordance with multiple Supplemental Type Certificates (STC’s) which included installation of a Lycoming O-235-L2C(M) engine and installation of a Sensenich fixed pitch propeller.

The engine limitations section of the FAA Approved Airplane Flight Manual Supplement (AFMS) associated with the engine and propeller modifications stated that the rated rpm was 2,800 and 125 horsepower for all operations. The performance section of the AFMS specified that the incorporation of the STC into the airplane would result in increased fuel consumption relative to the values given in the airplane flight manual.

According to the Airplane Type certificate Data Sheet, the total usable fuel capacity of the airplane was 24.5 gallons with an unusable fuel amount in each wing fuel tank of .75 gallon for a total unusable fuel capacity of 1.5 gallons. The Pilot’s Operating Handbook specified that the fuel consumed during engine start, taxi, and takeoff was 0.8 gallon. According to the engine Operator’s Manual, the fuel consumption in terms of gph varied from 9.5 gph at normal rated power to 5.8 gph at 65% rated power.

According to fuel records, 16.6 gallons of 100 low lead fuel were added on the morning of the accident, filling the fuel tanks. Operator records showed that between the time the airplane was fueled and the accident flight, the airplane flew 3 flights totaling 3.1 hours. The elapsed time for the accident flight was 2.2 hours as documented by the hour meter. The airplane was flown for a total of 5.3 hours since it was last fueled. AIRPORT INFORMATIONThe airplane was modified in accordance with multiple Supplemental Type Certificates (STC’s) which included installation of a Lycoming O-235-L2C(M) engine and installation of a Sensenich fixed pitch propeller.

The engine limitations section of the FAA Approved Airplane Flight Manual Supplement (AFMS) associated with the engine and propeller modifications stated that the rated rpm was 2,800 and 125 horsepower for all operations. The performance section of the AFMS specified that the incorporation of the STC into the airplane would result in increased fuel consumption relative to the values given in the airplane flight manual.

According to the Airplane Type certificate Data Sheet, the total usable fuel capacity of the airplane was 24.5 gallons with an unusable fuel amount in each wing fuel tank of .75 gallon for a total unusable fuel capacity of 1.5 gallons. The Pilot’s Operating Handbook specified that the fuel consumed during engine start, taxi, and takeoff was 0.8 gallon. According to the engine Operator’s Manual, the fuel consumption in terms of gph varied from 9.5 gph at normal rated power to 5.8 gph at 65% rated power.

According to fuel records, 16.6 gallons of 100 low lead fuel were added on the morning of the accident, filling the fuel tanks. Operator records showed that between the time the airplane was fueled and the accident flight, the airplane flew 3 flights totaling 3.1 hours. The elapsed time for the accident flight was 2.2 hours as documented by the hour meter. The airplane was flown for a total of 5.3 hours since it was last fueled. WRECKAGE AND IMPACT INFORMATIONAccording to the FAA inspector, the airplane impacted a residential area about 1 mile east of the Danbury Municipal Airport (DXR), Danbury, Connecticut. The right wing impacted near the roof line of a house adjacent to the shed, then impacted the shed. There was no postimpact fire. The airplane came to rest listing to the right. No fuel was drained from the left fuel tank which was nearly vertical and about 1.7 gallons were drained from the right fuel tank.

Examination of the fuel system following recovery revealed broken fuel supply lines in the cockpit area; however, there was no blue stains in those areas. Although the fuel supply line to the airframe fuel strainer was kinked and the bowl was separated from the firewall the bowl was drained and found to contain about 40 milliliters, or about 1 ounce of fuel. The carburetor bowl did not contain any fuel. There were no discrepancies with either fuel cap which were vented. No discrepancies other than impact damage were noted to the fuel supply lines. Due to impact damage the fuel gauges were not electrically checked.

Postaccident examination of the engine revealed no evidence of preimpact failure or malfunction of the powertrain, ignition, air induction, or exhaust systems. Throttle and mixture control continuity was confirmed from the cockpit to the carburetor. There were no nicks on the leading or trailing edges of either propeller blade and neither propeller blade exhibited scoring on the cambered side or blade face. One blade exhibited a slight aft bend.