What happened
On 15 September 2017, a Piper PA-39 Twin Comanche C/R, registration G-LARE, was conducting a flight for the purpose of revalidating an instrument rating and completing a multi-engine proficiency check. The flight, which included a pilot and an examiner, was nearing the end of a two-hour mission near Biggin Hill Airport.
While on the final circuit, the aircraft was configured for a simulated asymmetric approach, with the undercarriage extended and intermediate flaps selected. Due to traffic ahead, air traffic control instructed the crew to perform a left orbit late in the downwind leg. During this orbiting maneuver, the pilot retracted both the flaps and the undercarriage. Neither the pilot nor the examiner noticed that the aircraft's configuration had changed.
As the aircraft transitioned to the approach to land, the crew failed to perform further landing checks. During the flare, the propellers and the rear section of the fuselage struck the runway. The crew immediately initiated a go-around, at which point they identified that the undercarriage was not extended. The gear was subsequently deployed, and the aircraft completed a second circuit and landed safely without further incident.
The investigation
The investigation focused on the sequence of events during the orbit and the subsequent approach. It was established that the examiner, acting as the commander, was monitoring the aircraft ahead of them during the orbit. Because the examiner was not expecting a change in the aircraft's configuration, the retraction of the gear and flaps went unnoticed.
Investigators examined the crew's workload and the impact of air traffic control instructions. The investigation found that the crew was preoccupied with following the instruction to orbit and maintaining visual contact with preceding traffic. This preoccupation, combined with the conclusion of a long flight, contributed to the oversight.
Findings
- The aircraft's propellers, ADF antenna, and air-scoop sustained damage during the ground contact.
- There were no injuries to the crew.
- The primary cause of the incident was the failure to verify the aircraft configuration following the retraction of the undercarriage and flaps during an orbit.