Unusually powerful lightning blasted an F-16 jet Sept. 13 and may have crippled a second craft so badly that its pilot ejected and the plane crashed in the Great Salt Lake, the Air Force says.

A military investigating board's report of the incident, which left both pilots unscathed, confirmed that lightning damaged the plane that survived.Nellis Air Force Base Col. Hugh E. Gommel, president of the investigating board, would not state the cause of the other jet's impairment but indicated lightning was the logical cause.

Despite an intensive search, the downed plane was never recovered.

The report did mention similar cases and suggested improved lightning safeguards for the complex F-16s.

There was no evidence of collision between the Hill Air Force Base fighters, which were flying within a few feet of each other.

Before the strike, Capt. Hal K. Bird and Capt. Curtis L. Cook had flown a training attack on the Utah Test and Training Range west of the lake. They were setting up their approach to Hill about 6,000 feet above the water, the report said, flying through clouds and light rain.

One contributor to the report, Air Force electrical engineer Lawrence C. Walko, said rain showers were mild and there was little concern about thunderstorms, which pilots try to avoid.

However, Walko wrote, "A large percentage of aircraft incidents occur with this same weather scenario."