Mark Vannest was 26 when he disappeared after a short flight from Nantucket, Massachusetts, on July 18, 1984. He and his friend, also 26, Kenneth Antolino, flew to Nantucket in a Cessna 172; Antolino was piloting when the two men were last seen. They intended to return to Caldwell, New Jersey, but never arrived and were never heard from again.

No flight plan was filed for the return trip, a detail that complicated search efforts because there was no designated route to check. Despite extensive air and sea searches, no wreckage, debris, or other trace of the aircraft or the two men has been found. The North Plainfield Police Department in New Jersey continues to maintain open case files for both men.

The disappearance remains unsolved and the lack of physical evidence leaves many questions unanswered. If anyone knew the pair, their planned route, or saw the Cessna around July 18, 1984, authorities would welcome information.