Primary finding
Probable cause
<p style="margin-top:0pt;margin-bottom:8pt;line-height:108%;font-size:12pt;background-color:#ffffff;"><span style="font-family:'Roboto';color:rgb(0,0,0);background-color:#ffffff;">The in-flight separation of o</span><span style="font-family:'Roboto';background-color:#ffffff;">ne of the wooden propeller blades for unknown reasons.</span></p>
Investigator assessment
Analysis narrative
The pilot reported that he was maneuvering around weather at 11,500 ft mean sea level (msl) when he made a rapid descent to 3,500 ft msl to remain clear of clouds. He reported that he did not exceed the airplane’s maneuvering speed during the descent, and that when the airplane reached 3,500 msl, it began to “violently shake,” followed by a total loss of engine power. The pilot made a successful forced landing to a field; however, after he landed, he noticed about three-quarters of one of the wooden propeller blades was missing and two of the engine mounts were sheared from the firewall. The pilot stated the wooden P-prop had been overhauled and had accrued about 50-60 hours since overhaul. The pilot provided photographs of the fractured propeller blade; however, the detail observed in the photographs was insufficient to determine the reason the blade failed. Additional photographs were requested; however, they were not provided by the pilot. Therefore, the reason for the blade failure could not be determined.
Source record
Factual narrative
On July 10, 2024, about 1230 eastern daylight time, an experimental amateur-built Long-EZ airplane, N4JZ, was substantially damaged when it was involved in an accident near Thomasville, Georgia. The private pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that he was flying at 11,500 ft mean sea level (msl) maneuvering around weather when he was forced to descend “very quickly” to 3,500 ft msl to remain clear of clouds. The pilot said he did not exceed the airplane’s maneuvering speed during the descent. He reported that, when the airplane reached 3,500 ft msl, it began to “violently shake,” followed by a total loss of engine power. The pilot slowed the airplane to best glide airspeed and attempted to reach the Thomasville Regional Airport, Thomasville, Georgia; however, he was unable to reach the airport and performed a forced landing in a field. After exiting the airplane, the pilot observed that about three-quarters of one of the wooden propeller blades was missing, along with a section of lower engine cowling. Two engine mounts were also “perfectly” sheared off at the firewall. The pilot stated the wooden P-prop had been overhauled and had accrued about 50-60 hours since overhaul. Neither the FAA nor the NTSB traveled to the accident site. The pilot provided the NTSB photographs of the fractured propeller blade; however, the detail observed in the photographs was insufficient to determine why the blade failed. Additional photographs were requested; however, they were not provided by the pilot.