Because water and air present similar challenges in control, stability, electronics, hydraulics and propulsion, Boeing began adapting many systems used in jet airplanes for hydrofoils. The first were launched in 1962: Little Squirt, a 20-foot boat propelled by a waterjet; and High Point, a 110-foot submarine chaser that used propellers.
A 71-foot, 57-ton patrol gunboat, the Tucumcari, launched in 1967, was the first large hydrofoil to use waterjets instead of propellers. It could fly over the water at more than 55 mph in all kinds of weather.
The Tucumcari was effectively used during the Vietnam conflict and led to development of the missile-carrying Patrol Hydrofoil Missileship (PHM) for NATO, first launched Nov. 9, 1974.
Boeing built six PHMs, named Pegasus, Taurus, Aquila, Aries, Gemini and Hercules. The 131-foot PHM carried eight Harpoon antiship missiles, a 75 mm rapid-fire gun, Rapid Bloom Offboard Chaff System and an MK-92 fire control system.
Boeing launched its first passenger-carrying waterjet-propelled hydrofoil, the JETFOIL, in April 1974. It could carry from 167 to 400 passengers. The company built nearly two dozen Boeing JETFOILs for service in Hong Kong, Japan, the English Channel, the Canary Islands, Saudi Arabia and Indonesia.
| ||JETFOIL ||PHM
||March 29, 1974
||Nov. 9, 1974
||131 feet 2.5 inches
||28 feet 2.5 inches
||46 to 51.8 mph
||More than 46 mph
||4 feet 6 inches to 6 feet 6 inches
||8 feet 4 inches
||Two Allison 501-KF turbine engines with two Rocketdyne PJ-20 waterjet pumps
||Two waterjets powered by two 800-horsepower Mercedes-Benz diesel engines (hullborne), one waterjet powered by 17,000-horsepower GE marine gas turbine engine (foilborne)
||4 to 8 crew, 250 to 350 passengers
||21 to 24 crew