What happened
On 25 July 2000, a Bolkow BO-105DBS-4, registration G-NAAA, was conducting a public transport flight near Pendle, Lancashire. The mission involved landing on a road to collect a seriously injured individual. Upon approaching the landing site, the pilot identified the presence of telephone wires running alongside the road.
While the initial landing was completed safely, the aircraft encountered difficulty during the subsequent takeoff. As the helicopter lifted from the ground, one of the main rotor blades made contact with a wire, severing it. Despite the impact, the pilot did not experience any loss of control or adverse flight characteristics. To prioritize safety, the commander elected to relocate the aircraft to a different landing site approximately 2 nautical miles away. After landing at the second location and shutting down the engines, an initial inspection of the aircraft was performed, which failed to reveal any visible damage.
The investigation
Following the incident, the aircraft was taken to an engineering facility for a more thorough technical assessment. Investigators focused on the integrity of the rotor system to determine if the contact with the wire had compromised the structural components of the blades.
Findings
Detailed examination of the rotor assembly revealed that the contact with the telephone wire had caused minor delamination of the erosion strip on one of the main rotor blades. The damage was measured at approximately 5 inches in length.