What happened
On 6 July 2002, a DHC-1 Chipmunk 22, registration G-BCSL, was involved in a ground collision at Barton Aerodrome, Manchester. The aircraft, operated for private use, was parked facing a hangar door following a previous flight that day.
While attempting to commence a left turn, the pilot released the wheelbrakes and applied left rudder. However, the turn failed to initiate as expected. In an attempt to expedite the maneuver, the pilot applied the left wheelbrake, but the aircraft continued to move forward slowly. During this period, the propeller and spinner struck the hangar door, causing the engine to shockload and resulting in significant damage, including a ruptured left wing fuel tank.
The investigation
The investigation examined the aircraft's braking system and the pilot's handling of the maneuver. The DHC-1 Chipmunk 22 features a unique braking system where differential braking is achieved by varying the position of a hand-operated lever and the rudder pedals.
An engineering assessment conducted by a licensed engineer in the presence of the aircraft owners found no faults with the handbrake system, the locking latch, or the ratchet mechanism. However, the investigation noted a discrepancy regarding the aircraft's maintenance history. While the ownership group maintained the aircraft had been defect-free for the preceding month, the pilot reported a history of intermittent braking issues on G-BCSL, citing five previous instances of brake problems, though these were not documented in the aircraft's official logs.
Findings
- The collision was caused by the ineffective application of left rudder and left wheelbrake during the turn.
- There was conflicting evidence regarding the reliability of the braking system, with the pilot reporting intermittent failures that were not recorded in the aircraft's technical logs.
- The aircraft was positioned facing a solid obstacle (the hangar door), which increased the risk of impact during a failed maneuver.