Wire strike protection system

[1]: 9  Over a similar period covering the ten years between 1970 and 1979, 208 civil helicopters were involved in wire strike accidents.

[3][4] Bristol staged a series of 52 tests of the WSPS by mounting it on the fuselage of a wrecked Kiowa; the fuselage was loaded onto a flatbed truck and driven into wires at speeds ranging from 15 to 60 mph (13 to 52 kn; 24 to 97 km/h), yaw angles ranging from 0 to 45°, and a variety of cables that were typically used in overhead power and telecommunication transmission lines, including a 3⁄8 in (9.5 mm) 7-strand steel cable with a tensile strength exceeding 10,000 lb (4,500 kg).

[1]: 11  An additional deflector to protect the skids, landing gear, and tail boom (including the rotor and vertical stabilizer) was also tested, but was found to be ineffective.

[1]: 11, 15–19, 41 During the Langley tests, an OH-58 was attached to the end of a 196-foot (60 m) long cable, pulled back, and released to swing through wires mounted horizontally at a height of approximately 22 feet (6.7 m).

[1]: 15 Wire Strike Protection System is a registered trademark of Magellan Aerospace, the parent company of Bristol via acquisition.