Accident Overview
On March 11, 2023, about 1130 mountain daylight time, an experimental amateur-built Zenith CH 801, registration N638BH, was substantially damaged during an accident near Brigham City, Utah. The pilot and one passenger were uninjured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Flight History
The pilot reported that after departing from Brigham City Regional Airport (BMC), the airplane experienced a loss of thrust while climbing through 200 to 300 feet above ground level. Although the engine continued to run, the airplane could not maintain altitude. The pilot decided to land on the remaining runway. During the landing, the airplane touched down hard, causing the nose landing gear to collapse. Postaccident, the pilot defueled about 40 gallons of fuel from the airplane.
A pilot-rated passenger noted that during the first circuit in the traffic pattern, while on the downwind leg, the engine rpm appeared to fluctuate, as if surging. The passenger, unfamiliar with this aircraft type, was unsure if the fluctuation was normal. On final approach, the pilot moved the propeller control full forward, landed, and initiated a second takeoff. During the initial climb, the pilot reported a lack of power. The passenger observed that engine rpm seemed normal. The pilot then announced that power had returned. The passenger, observing ample runway remaining, recommended landing. During the landing flare, the airplane landed hard again.
Postaccident Examination
Examination of the airplane revealed structural bending of the aft fuselage. Flight control continuity was confirmed from all primary flight control surfaces to the cockpit controls. Inspection of the airframe and engine found no preaccident mechanical failures or malfunctions that would have precluded normal operation. The fuel system was visually inspected, with continuity established from the main fuel tanks to the carburetor. The airframe fuel strainer was empty.
Engine Testing
An external fuel source was connected to the right-wing fuel inlet line to conduct a test run. The engine started on the first attempt and ran smoothly through various power settings for about 5 minutes. Due to propeller damage, the throttle was not advanced to full power, but the engine achieved a static rpm of 2,600. The propeller governor was removed for examination; no visible damage was found, and the governor control lever moved freely. Functional testing of the propeller governor showed it performed within manufacturer specifications.
Conclusion
No probable cause was determined from the investigation. The accident resulted in substantial damage to the aircraft but no injuries to the occupants.