MANSFIELD.
“On the night of October 18, 1973, a US Army Reserve UH-1H Iroquois helicopter, tail number 68-15444, was flying from Columbus to Cleveland, Ohio at approximately 2,500 feet.”
The light closed on the helicopter at extremely high speed. Coyne took the controls and put the UH-1H into a 500-foot-per-minute powered descent and increased airspeed to maximum. The unknown craft, described by all four crewmen as a grey, metallic, cigar-shaped object with a red light on its nose, a white "tail" light, and a green steerable beam emerging from its underside, came to a hover above the helicopter. The green beam swept into the cockpit. The helicopter's compass began spinning and the radio went dead.
When Coyne and Jezzi looked at the altimeter, the helicopter — which they had been deliberately descending — was instead climbing through 3,500 feet at an unaccounted-for 1,000 feet per minute. The unknown craft eventually accelerated to the west and disappeared. Coyne regained radio contact, declared the encounter, and landed at Cleveland-Hopkins. The crew filed an official Department of Army report.
The Mansfield case was independently corroborated by ground witnesses on the highway below, who described a red and green light formation hovering and then accelerating away. The case was investigated by Jennie Zeidman of CUFOS, who interviewed all four crew members and traced their reports through Army channels. The crew's military careers were unaffected; none recanted; all maintained their accounts. Captain Coyne later spoke at the United Nations General Assembly's UFO discussion in 1978. The case remains officially unexplained.