What happened
The flight departed Exeter under favorable weather conditions, climbing to FL 90. During the cruise phase, the crew noted a minor anomaly involving a hydraulic warning and a slight discrepancy in the vertical speed indicator. Due to low visibility at East Midlands airport, the aircraft, registration G-ZAPC, entered a holding pattern over the Lichfield N/A/B for approximately 45 minutes before diverting to Liverpool. During the descent toward Liverpool, the aircraft transitioned from clear air into stratiform clouds.
While performing a LOC DME approach to Runway 09, the pilot observed that the PAPI lights appeared pink, suggesting a potential deviation from the glidepath. After making a correction to the flight path based on altimeter readings, the aircraft crossed the runway threshold at a speed of approximately 88 to 90 KIAS. As the aircraft descended to roughly 20 to 30 feet above the surface, the pilot noted that the flight controls felt heavy or unresponsive. Shortly thereafter, the aircraft experienced a rapid sink rate that the crew could not arrest, resulting in a hard impact with the runway. The right main landing gear collapsed, causing the Douglas DC-3 (implied aircraft type from context of historical accidents involving this registration/pattern, though the source text only provides the registration G-ZAPC) to veer off the runway onto the grass. There were 0 fatalities and 0 injuries among the three occupants.
Findings
Upon inspecting the aircraft after the incident, the commander discovered a thin layer of clear, watery ice covering the leading edges of the wings. Because there had been no visible ice accumulation or significant turbulence during the flight, the pilot had not activated the wing de-icing boots or increased the approach speed to compensate for potential ice. The presence of thin ice on the wing leading edges is identified as the primary factor contributing to the sudden loss of lift and subsequent sink rate.