What happened
On 25 May 2020, a Piper PA-28RT-201 Arrow IV, registration N2943D, was performing a private flight at Enstone Aerodrome, Oxfordshire. While flying the downwind leg for Runway 26 North as part of a standard overhead join, the pilot observed a low-level helicopter that appeared to be joining the circuit on the base leg. Because the helicopter had not communicated via the Air/Ground frequency, the pilot became uncertain of its intentions.
This period of distraction interrupted the pilot's pre-landing procedures. During the flare for landing, the pilot realized that the landing gear had remained retracted. The aircraft subsequently made a gear-up landing on the grass surface of Runway 26 North. The impact caused damage to the propeller, the underside of the fuselage, the left flap, and the right step. There were no injuries to the pilot.
The investigation
The investigation established that the pilot was performing pre-landing checks from memory rather than utilizing the written checklist. Following the distraction caused by the helicopter, the pilot resumed the checks from the point he believed he had reached, rather than restarting the sequence. Furthermore, the pilot did not perform the customary 'Mixture/Prop/Wheels' memory check during the final approach.
It was also noted that the pilot had limited recent flying experience due to weather conditions and COVID-19 restrictions. While the pilot recalled hearing the 'wheels up' warning buzzer during the initial descent, he had no recollection of the buzzer sounding during the base or final approach legs.