What happened
On 18 February 2006, a Schweizer 269C-1, registration G-CCJE, was performing a demonstration flight at Sheffield City Airport. The flight was intended to show a passenger, who had recently acquired a similar helicopter, how to perform an autorotation. Following an uneventful period of flight, the commander initiated a practice engine-off landing using a power recovery method.
During the approach, the pilot maintained an airspeed of approximately 50-55 knots. As the aircraft reached 150 feet agl, the pilot commenced the flare. Despite attempting to raise the collective lever to cushion the descent, the aircraft maintained a high rate of descent. Upon contact with the ground, the skids dug into the soft, rain-softened surface. This caused the helicopter to tip forward and roll onto its right side. The impact shattered the canopy, but the two occupants were able to exit the aircraft with only minor injuries. There was no fire following the impact.
The investigation
The investigation focused on the mechanical state of the engine and the environmental conditions at the time of landing. The engine was removed from the airframe and subjected to testing in a specialized cell. This process involved disconnecting the oil cooler and severing the throttle and mixture controls. Tests confirmed that the fuel system, including the electric boost pump and gravity feed, was functional, and the fuel gascolator was clean. The engine performed normally during the test schedule, with no evidence of mechanical failure or issues with the fuel-driven pump. The only notable observation was a slight low oil pressure, which was deemed non-significant and likely attributable to the relief valve.
Findings
- The aircraft was operating near its maximum permitted weight, with the combined weight of the crew and fuel being within approximately 20 kg of the limit.
- The approach was made with a tailwind component, which the pilot had not fully accounted for.
- The pilot did not realize the ground was particularly soft or boggy, which prevented a successful run-on landing.
- The high rate of descent was likely exacerbated by the aircraft's high weight and the tailwind, making the flare less effective.