What happened
On 29 June 1998, two separate incidents involving Bell 20 फीसदB helicopters occurred at Wycombe Air Park, Buckinghamshire. The first aircraft, G-BLZN, was performing a public transport flight and was returning to its base helipad. The helipad featured four landing spots arranged in a linear formation, spaced approximately 11.9 metres apart.
As the pilot of G-BLZN approached the pad, he observed another helicopter, an Agusta Bell 206B registered as G-BUZZ, occupying the third landing spot (H3) with its rotors active. The pilot of G-BLZN taxied to the first spot (H1) and repositioned the aircraft to a westerly heading. After stabilizing, the pilot moved the aircraft to the second spot (H2) and landed to begin shutdown procedures.
Shortly after landing, the pilot felt and heard an initial impact, which he initially suspected was a strike to the tail rotor. Following a second impact, a passenger alerted the pilot that the rotor blades of the two helicopters were colliding. Although the pilot initially doubted this, he attempted to reposition the aircraft slightly to the left. This resulted in a series of further impacts that caused the aircraft to become unstable. The pilot successfully evacuated the passenger before the helicopter rolled onto its right side.
At the same time, G-BUZZ was positioned on H3, awaiting takeoff clearance. The aircraft sustained a gash to its left side and damage to its main rotor blades during the encounter. The crew of G-BLZN sustained minor injuries, while the pilot of G-BUZZ was uninjured.