Loss of engine power (partial): RotorWay Exec 162F, C-GBZD, accident occurred on December 7, 2025, at Chemehuevi Valley Airport (49X), Lake Havasu City, Arizona

• Location: Lake Havasu City, 
• Arizona Accident Number: WPR26LA056 
• Date & Time: December 8, 2025, 10:30 Local 
• Registration: C-GBZD 
• Aircraft: Rotorway Exec 
• Aircraft Damage: Substantial 
• Defining Event: Loss of engine power (partial) 
• Injuries: 1 None 
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/202144/pdf

https://data.ntsb.gov/Docket?ProjectID=202144

The pilot/owner of an amateur-built helicopter reported that, while transitioning through translational lift for landing at about 30 ft above ground level with near-zero forward airspeed, the engine experienced a loss of power. The pilot/owner attempted to perform an autorotative landing by increasing collective and applying left pedal, and the helicopter subsequently experienced a hard landing, bounced, and came to rest on the edge of the runway at an 45° angle. The helicopter then rocked backward, resulting in substantial damage to the tailboom and tail rotor blades.

The pilot’s post-accident examination of the engine revealed that it started normally during a test run; however, the engine would not accelerate above idle power. Further examination determined that the throttle cable was disconnected due to a missing retaining nut. The pilot reported that he had installed a nyloc self-locking nut, but the bolt threads did not extend sufficiently into the nut to engage the nylon insert and secure the nut. As a result, the nut separated in flight, which allowed the throttle to move to the idle position and resulted in a loss of engine power.

- Probable Cause: The pilot’s improper securing hardware installation, which resulted in a loss of throttle control and a loss of engine power.