WHITING FIELD, Fla. (AP) _ Two Navy pilots killed in a collision were participating in an unauthorized five plane formation and at one point lost sight of other planes, according to a naval investigation.

Lt. Cmdr. Joseph Linehan, a flight instructor, failed to brief the group adequately on the maneuver and showed poor judgment in participating in an unauthorized formation, according to the Navy's review of the accident released this week.

Investigators also concluded that a communication breakdown and Linehan losing sight of the other planes also contributed to the accident.

Linehan, 35, of New York City, was killed in the June 11 crash along with Marine 2nd Lt. Lara Vincent, 23, of Mystic, Conn.

The report recommended that instructor pilots receive approval before deviating from training exercises and for formations involving more than three planes.

The accident happened while squadron members were en route to Key West Naval Air Station. Once they got in their places, Linehan told the group via radio that the sun was in his eyes and he moved about 100 feet to the right of the formation to take photos.

Linehan, then, moved out of the others' sight but tried to rejoin the formation and reappeared near another plane, clipping its underside. The tail of his plane was severed by the other plane's propeller.

Ms. Vincent, a Marine Corps student pilot in Linehan's plane, freed herself but her parachute didn't deploy fully and she became tangled in the wreckage.

The single-engine, turboprop T-34C Turbo Mentor went down in about two feet of water in Tavernier, in the upper Florida Keys.