- Location: Geneva, Ohio
- Accident Number: ERA24FA310
- Date & Time: July 21, 2024, 17:54 Local
- Registration: N751TX
- Aircraft: WILLIAMS JOHN TITAN T-51 MUSTANG
- Aircraft Damage: Substantial
- Defining Event: Powerplant sys/comp malf/fail
- Injuries: 1 Fatal
- Flight Conducted Under: Part 91: General aviation - Personal
https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194729/pdf
https://data.ntsb.gov/Docket?ProjectID=194729
On July 21, 2024, about 1754 eastern daylight time, an experimental, amateur-built Titan T-51 Mustang, N751TX, was substantially damaged when it was involved in an accident near the Germack Airport (7D9), Geneva, Ohio. The commercial pilot was fatally injured. The airplane was operated by the pilot as a personal flight conducted under the provisions of Title 14 Code of Federal Regulations Part 91.
The pilot, who was the builder of the experimental amateur-built airplane, was conducting a post-maintenance test flight. After performing several aerobatic maneuvers near the airport, the pilot began a high-speed low pass over the runway. Upon passing most of the runway, the airplane began a climb. A witness heard the engine go to a high rpm and then saw the entire propeller hub break apart. After the propeller hub fractured and separated, the airplane began a left turn toward a road. While maneuvering toward the road, the airplane's left wing impacted a tree and the airplane subsequently rolled over and impacted terrain.
Onboard recorded data revealed that, at the time the propeller separated, the engine was operating at 6,813 rpm, which equated to a propeller speed of 3,585 rpm. This speed was considerably in excess of the propeller blade blank manufacturer's limit of 2,100 rpm. This speed would have produced a centrifugal force that was more than 3 times the design limit of the propeller blade blanks. Further examination of the onboard data revealed that, around the time of the propeller overspeed, the airplane was traveling at an airspeed about 223 miles per hour (mph); the published never-exceed speed (Vne) for the airplane was 215 mph. The data also revealed a sudden decrease in the longitudinal load factor, consistent with a sudden deceleration of the airplane, followed shortly thereafter by the longitudinal load factor returning to normal. A possible reason for the deceleration was a sudden increase in drag from the propeller blades moving to low pitch. This was followed by a reduction in drag on the airplane, which was likely due to the propeller separating from the airplane.
Postaccident examination of the propeller governor, governor adapter, and the propeller gearbox revealed no evidence of any preacident mechanical failures or malfunctions that would have precluded normal operation. Ultimately, the reason for the propeller overspeed could not be determined based on available information.
- Probable Cause: A sudden propeller overspeed and subsequent separation of the propeller blades and hub, while maneuvering at high speed and at low altitude, which resulted in a collision with a tree during the subsequent forced landing attempt.
According to FAA airman records, the pilot held a commercial pilot certificate with ratings for airplane single-engine land and sea. He also held a flight instructor certificate as well as a repairman - experimental aircraft builder for the accident airplane. He reported 12,500 flight hours at the time of his most recent FAA medical examination in October 2023, and 100 hours logged within the six months before the examination.
The converted LS auto engine was just too much twist for the prop to handle. The pilot was really asking for it too, blasting past all of those red lines like that.
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