Accident Overview
On 28 July 2008 at 16:20 UTC, a Hughes 269A (Hughes 300) helicopter, registration G-SHPP, sustained damage beyond economic repair after a loss of tail rotor authority and a subsequent ground impact near Peacehaven, East Sussex. The flight was a private reconnaissance mission with one pilot and one passenger, both unharmed.
History of the Flight
The pilot intended to conduct a low-level reconnaissance of a potential landing site before returning to Redhill Airfield. After two orbits to assess the safest approach, the pilot approached the field from the north-west and entered an into-wind hover at approximately 100 feet above ground level (AGL). Due to a group of horses nearby that would have been closely overflown by an into-wind departure, the pilot executed a pedal turn to depart downwind along the same ground track as his arrival. Aware of the downwind condition, he attempted a slow transition to forward flight from the hover. During the transition, the helicopter began a gentle sink, which the pilot counteracted by raising the collective lever. The helicopter then yawed to the right; the pilot applied left pedal but found insufficient travel to stop the yaw. Noticing that rotor rpm (rrpm) had decreased, the pilot realised that lowering the collective was necessary to recover rrpm, but insufficient height remained. The helicopter touched down at the top of a small slope, struck a fence, and rolled over onto its left side. Both occupants, wearing full harnesses, exited through the right door uninjured.
Overpitching and Contributing Factors
The pilot assessed that overpitching of the main rotor caused the rrpm loss, leading to loss of tail rotor authority. Overpitching occurs when the pilot increases blade pitch without sufficient engine power to overcome increased rotor drag. The investigation identified four likely contributing factors: (1) the relatively high temperature (25°C at Shoreham) reduced available engine power; (2) the helicopter was operating close to maximum gross weight; (3) a downwind transition demands more power than an into-wind transition; and (4) the H269A's main rotor rotates anti-clockwise, so left pedal application requires additional engine power.
Weather Conditions
The 1550 UTC weather report from Shoreham indicated a surface wind of 110°/6 kt, temperature 25°C, and QNH 1011 mb.