What happened
On March 15, 2009, at approximately 11:50 local time, a Beech 35-B33, registration D-EJPU, was involved in a landing gear retraction accident at Bolzano Airport. The aircraft, operated by a private individual, had departed from the same airport approximately 35 minutes earlier for a local pleasure flight.
Upon landing, while the aircraft was still in motion on the runway, the landing gear was inadvertently retracted. This action caused the fuselage to impact the runway surface immediately. The aircraft continued to slide for approximately ten meters before coming to a halt. The incident resulted in one injury to the passenger and extensive damage to the aircraft's propellers and the lower portion of the fuselage.
The investigation
The ANSV investigation focused on the sequence of cockpit actions and the mechanical reliability of the aircraft's safety systems. The pilot admitted to mistakenly operating the landing gear lever instead of the flap lever. Investigators noted that the cockpit configuration of this specific aircraft was unusual; the gear lever was positioned to the right of the flap lever, which is the inverse of the standard layout found in most retractable-gear aircraft. This peculiar arrangement is a known characteristic of certain older Beechcraft models.
Furthermore, the investigation examined the effectiveness of the manufacturer's original safety switch, designed to prevent gear retraction while the aircraft is on the ground by sensing compression in the landing gear struts. The investigation found that because the aircraft was still traveling at a high speed during the error, aerodynamic lift likely reduced the compression on the struts, preventing the safety switch from disabling the retraction circuit.
Findings
- The primary cause of the accident was the inadvertent retraction of the landing gear lever by the pilot in place of the flap lever.
- The pilot performed the after-landing checklist before clearing the runway, a phase where attention is still heavily focused on the recent landing.
- The aircraft's original safety switch failed to prevent the retraction because the high ground speed created enough lift to reduce strut compression.
- The aircraft had not been retrofitted with optional safety modifications (Service Instructions 0938 or 1215) which were designed to provide additional protection against accidental retraction or to install a guard on the lever.
- The cockpit layout, featuring reversed lever positions compared to standard aircraft, contributed to the pilot's error.