Incident Overview
On 16 May 2000 at 1444 hours UTC, an Enstrom 280FX helicopter, registration G-BXRD, experienced a landing incident at Shoreham Airport, West Sussex. The helicopter sustained a bent main rotor blade. The pilot, the sole occupant, was not injured.
Aircraft and Pilot Information
The helicopter, manufactured in 1986, was powered by one Lycoming HIO-360-F1AD piston engine. The pilot held a Private Pilot's Licence (Helicopter) and was 69 years old at the time. His total flying experience was 1,200 hours, with only 9 hours on the Enstrom 280FX type. In the preceding 90 days, he had logged 15 hours, including 7 hours in the last 28 days.
Pre-Flight Background
The flight was the pilot's first since completing an Enstrom type conversion. During training, the instructor noted a stiff throttle and incorrect collective/throttle correlation, along with high exhaust gas temperature (EGT). A local company performed rectification work, after which the pilot found the throttle much freer. He was advised that the mixture was slightly lean but that keeping EGT below 165°F would be acceptable. The ADF was also unserviceable.
Flight Details
The pilot departed Shoreham at 1428 hours for a private site at Little Stoughton, north-northeast of Shoreham. During climb, he observed high EGT for the manifold pressure setting. Due to the unserviceable ADF and difficulties with the NKS80 VOR receiver, he decided to abandon the flight and return to Shoreham.
Weather at Shoreham at 1450 hours was reported as: wind 200°/10 knots, visibility 8,000 meters, few clouds at 400 feet and scattered at 2,500 feet.
Return and Hover Incident
After receiving traffic information, the pilot was cleared to approach Helicopter Training Area (HTA) Whiskey. Another helicopter approaching HTA November prompted the Enstrom pilot to route west to maintain separation. When clear, he approached Whiskey but found himself high, so he allowed the helicopter to drift south, arriving at a high hover approximately 12 feet above the ground near the western edge of Runway 21. Air Traffic Control (ATC) requested he hold due to departing traffic on Runway 21. Considering himself too close to the runway, the pilot initiated a left spot turn to hover taxi west. At that point, he lost control and realized the helicopter was slowly losing height. Raising the collective pitch lever did not prevent the descent.
Descent and Damage
Although it became clear the helicopter could not be prevented from landing, the pilot anticipated a gentle touchdown on rough grass. However, he was unaware that the rough grass concealed a deep, water-filled ditch. The descent into the ditch was gentle, cushioned by dense vegetation, but the main rotor blades struck the ground, bending them. The pilot shut off fuel and electrical power and remained with the helicopter until airfield Rescue and Fire Fighting Service (RFFS) personnel used ladders to evacuate him from the ditch.
Pilot's Assessment
The pilot considered that during the hover, he inadvertently reduced power when making collective pitch control changes due to the much freer throttle and increased workload. He also noted it was probable that the left spot turn positioned the helicopter downwind, compounding the reduced power issue.