What happened
On 15 July 2016, a Zenair CH 601UL Zodiac, registration G-CCZK, was conducting a private flight from Popham Airfield in Hampshire. Following a standard pre-flight inspection—which included checking oil and coolant levels and sampling fuel for contamination—the pilot successfully started the engine and completed all necessary run-up checks without issue.
As the aircraft climbed away from the airfield, passing approximately 350 ft and clearing the boundary, the pilot experienced a sudden reduction in engine power and significant vibrations. In an attempt to maintain flying speed, the pilot lowered the aircraft's nose and adjusted the throttle, but the engine continued to run poorly. The pilot notified Popham Airfield via radio that a forced landing was being attempted in a field located to the west of the airfield.
During the landing sequence, the aircraft entered a field of wheat, where the rapid deceleration caused damage to the propeller, the left wing, and the left landing gear. There were no injuries to the pilot or the passenger.
The investigation
The investigation was based on the aircraft accident report submitted by the pilot. Investigators reviewed the sequence of events from the pre-flight checks through to the impact. The examination focused on the engine's performance during the climb and the subsequent mechanical behavior. While the physical damage to the airframe was documented, the investigation found that the specific reason for the engine's loss of power remained undetermined.