Thatcher CX4 N274DR

Summary

On 24 June 2020 at about 18:45 local time, a Thatcher CX4 registered N274DR was involved in an accident near Upland, California, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 June 2020 at 18:45

Classification

Accident

Location

Upland, California, United States

Nearest airport

Cable (CCB)

Coordinates

34.1094, -117.6950

Aircraft

Thatcher CX4

Registration

N274DR

Category

Airplane

Year built

2017

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Upland → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR20LA193

1 person was seriously injured.

The inflight separation of the propeller assembly due to a fatigue fracture of the crankshaft. Contributing to the accident was the pilot’s restricted visibility during landing, which resulted in an excessive approach speed, a long landing, and subsequent impact with terrain.

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

Read the full NTSB narrative

The pilot reported that while returning to the airport after an uneventful flight, the propeller separated from the engine, which resulted in the windscreen and canopy being covered with oil and restricting forward visibility. The pilot continued toward the airport; however, as the airplane crossed the threshold of the runway, he noted that he was going way too fast as he was attempting to keep the airplane aligned with the runway. Subsequently, the airplane touched down near the departure end of the runway, bounced, and impacted the ground. Postaccident examination of the airplane revealed substantial damage to the fuselage and both wings. The propeller assembly and a portion of the engine crankshaft was separated and not located. Examination of the remaining portion of the crankshaft revealed that two fractures initiated at the termination of a square keyway slot in the crankshaft. The presence of ratchet marks at the fracture origins and the presence of progressions marks along the fracture path were indicative of fatigue fracture initiation and growth.

Quoted verbatim from the NTSB record.