What happened
On 5 April 2012, a DH110 Sea Vixen, registration G-CVIX, was performing a post-maintenance re-familiarisation flight at Bournemouth Airport. Following a touch-and-go maneuver, the aircraft completed its landing roll. While performing the 'After Landing' checklist, the pilot inadvertently moved the landing gear selector to the 'up' position. This action triggered the retraction of both the nose and the left main landing gear.
The aircraft subsequently dropped onto its nose and the left under-wing fuel tank. The impact caused damage to the forward fuselage and the left fuel tank, leading to a fuel leak that required foam application by the airport's fire and rescue service. The aircraft came to rest on the paved surface after a slight 45-degree turn. There were no injuries to the pilot.
The investigation
The investigation examined the cockpit controls and the pilot's recent flying history. It was noted that the pilot had recently been flying the Hawker Hunter and BAe Hawk, both of which feature a flap selector switch located in a position very similar to the landing gear selector on the G-CVIX.
Technical examination focused on why the landing gear retracted despite safety microswitches designed to prevent ground retraction. While the aircraft's systems could not be fully tested due to the damage and maintenance delays, testing of the left main gear microswitch confirmed it was functioning correctly. The investigation also looked at the landing gear configuration, noting that the aircraft was set up with increased oleo pressure to accommodate heavier pylon-mounted fuel tanks.
Findings
- The pilot's recent experience with aircraft featuring similarly positioned flap selectors led to the inadvertent selection of the landing gear to the up position during the after-landing checklist.
- A combination of high main landing gear oleo pressure (set for heavier operations) and a low landing weight prevented the left main gear microswitch from compressing sufficiently to block the retraction.
- There was no specific guidance in the flight documentation regarding the precise timing for performing 'After Landing' checks.