Mooney M20C N2953L

Summary

On 3 April 2021 at about 16:48 local time, a Mooney M20C registered N2953L was involved in an accident near College Park, Maryland, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 April 2021 at 16:48

Classification

Accident

Location

College Park, Maryland, United States

Nearest airport

College Park (CGS)

Coordinates

38.9822, -76.9241

Aircraft

Mooney M20C

Registration

N2953L

Category

Airplane

Year built

1967

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Unknown → Tangier Island

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA21LA170

Nobody was injured.

Improper maintenance of the airplane by its owners and their failure to have qualified maintenance personnel determine the root cause of water infiltration into the fuel system. Also causal was the pilot’s inadequate preflight inspection, which failed to remove all of the water contamination from the fuel system prior to the flight and resulted in the partial loss of engine power during the takeoff. Contributing was the pilot’s exceedance of the critical angle of attack, which resulted in an aerodynamic stall and subsequent hard landing.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot planned for a recreational trip of 2 hours or less. During his preflight inspection, he found, “a bunch of water” in the left fuel tank, which he said he continued to sample until it was free of water. He then dried his collection tube and sampled the tank twice more reporting the sample was clear with no water. Before departure, with the fuel selector positioned to the left fuel tank, he performed an engine run-up with no engine or engine systems discrepancies reported. During takeoff he rotated at 83 mph and when over the runway the engine began to “cough/sputter.” He continued straight ahead, but review of airport surveillance video revealed that the airplane likely stalled and landed hard resulting in substantial damage to the left wing. A postaccident examination of the airplane found that there was water in the flexible fuel hose from the firewall fitting to the engine-driven fuel pump inlet, and about 5 ounces of fluid drained from the carburetor bowl contained equal parts of fuel and water. On-wing pressure testing of the fuel caps revealed extensive leakage from both and a subsequent examination revealed evidence of unapproved or missing parts from both caps. The correct parts were then installed on both caps and they passed testing to 25 psi, but leakage was noted during on-wing pressure testing. Additional testing identified leakage between the adapter and the doubler of each assembly at low pressures, which increased in intensity as the pressure increased. Prior to the accident flight, the co-owners of the airplane replaced the seals on both fuel caps which did not eliminate the water intrusion. In addition, they purchased wing covers in an attempt to further reduce the potential for water intrusion; however, they were not installed on the airplane when the pilot arrived at the airport for the accident flight. They did not alert their mechanic of the issue. Although the pilot reportedly sampled the left fuel tank until water was no longer present, he likely did not drain out all the water from the tank nor did he drain the selector valve sump as part of his inspection. The results of the extensive postaccident testing revealed that even if the fuel caps were repaired properly, additional issues were present with each fuel tank filler cap assembly that were not addressed by the owners. Had the owners consulted with their maintenance provider about the water intrusion, it is likely that the root cause of the water intrusion could have been identified.

Quoted verbatim from the NTSB record.