Crowley, Walter A. (1917-2008)

  • By Walt Crowley
  • Posted 10/17/2006
  • Essay 7987
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Walter A. Crowley, in recent years a resident of Oak Harbor, Washington, was an inventor and engineer who developed the first practical air-cushion vehicle in the summer of 1957 in Detroit, Michigan. The following year, he filed the first patent for an air-cushion vehicle, in this case a high-speed train straddling a triangular track, and built a large "ACV" capable of carrying two adults (now in the Smithsonian Air & Space Museum collection). At virtually the same time, Sir Christopher Cockerell (1910-1999) developed similar concepts in Great Britain. Government funding propelled Cockerell's "hovercraft" to greater fame, but he acknowledged the originality of Crowley's work. Crowley went on invent the flexible skirt used on virtually all hovercraft as well as an efficient air-bearing system later commercialized by the Boeing Company as "Aero-Go." Crowley retired in the 1980s, lived on Whidbey Island with his second wife, Lily, and  continued to pursue air cushion research in his home workshop. Walter Crowley died in May 2008.

A Michigan Mechanic

Walter Alfred Crowley was born in greater Detroit on January 31, 1917. His father, Frank, was an itinerant carpenter and barn painter, and his mother, Clara, later trained as a registered nurse and became the first woman in Michigan to found and operate a convalescent home. Crowley was pursuing pre-med studies at Wayne State University in Detroit when World War II intervened. He met his first wife Violet while stationed in Hull, England, and they returned to the Detroit area in 1945. Their only child, Walter Charles "Walt" Crowley (1947-2007), was born in 1947.

Crowley was employed as an engineer first by General Motors and then by the Chrysler Missile Division, where he worked on guidance systems for the Redstone and Jupiter intermediate-range ballistic missiles. He designed the family home in Flint, Michigan, complete with a key-operated electric garage door, which delivered a healthy shock in the rain, and an electric sliding door for the bathroom, which would often open without warning to expose occupants in flagrante delicto.

Flight Without Height

He also dabbled in aircraft design and built a Benson "Gyrocopter," an unpowered autogyro towed from a car like a kite. After two serious crashes, Crowley focused on the idea of "flight without height." Remembering how warm air trapped in a just-washed cup would cause it to rise and slide across a smooth kitchen counter, Crowley began experimenting with "ground effect." He observed that blowing air into the center of a conical lampshade would cause it to rise and hover steadily above any surface, including water. This triggered the idea for a "hydro-air" vehicle that could traverse land or sea on a cushion of air without physical contact or friction.

In Crowley's design, lift is produced by the movement of large volumes of air at low pressure inside an open "plenum chamber" like an inverted bowl. Virtually simultaneous work in England by Sir Christopher Cockerell employed high pressure air pumped through annular jets or rings on the bottom of the vehicle. This concept was later abandoned in favor of Crowley's plenum design, augmented by inflated flexible skirting, which he also invented.

Indoor Kitty Hawk

Crowley moved to Royal Oak, a Detroit suburb, in 1956 and pursued his basement workshop research with various plenum chamber designs. In 1957, he stretched canvas around a tubular frame to create a conical machine large enough to carry a passenger. When he and his wife proved too heavy for the original engine, he enlisted his son as a test pilot. As the younger Crowley later told author Adam Woog,

"I remember when my father first switched on his creation. The blast of air scattered laundry and dusty bric-a-brac and lifted the machine an inch above the floor. Looking like an overgrown green lampshade, the thing torqued and glided freely around the basement. My father gingerly mounted the platform, but his adult weight was too much for the motor. So at the age of ten, I was recruited to become the first 'man' to fly an air-cushion vehicle. The precise date of this indoor Kitty Hawk has been lost, but I remember we were giving demonstrations to the relatives by Thanksgiving 1957" (Woog).

There Goes the Neighborhood

Based on the success of this machine, the elder Crowley built a larger, lozenge-shaped vehicle in his garage. During the first outdoor test flights, in the spring of 1958, the neighbors called the police. They in turn summoned a flatbed truck to haul the vehicle to City Hall where they took turns flying it in the parking lot. (The Smithsonian Air & Space Museum added this vehicle to its collection in 1961.)

Associates at Chrysler promoted Crowley's invention to the company and the military, but little came of this advocacy. As his noisy experiments attracted press attention, he was contacted by organizers of Spacetronics, Inc. in Bethesda, Maryland. They hired Crowley and took control of his patents on the promise of providing capital to develop his ideas.

Betrayed but Unbowed

The family relocated to Bethesda in fall 1958, and Crowley designed and built a heavy-duty, all-metal prototype vehicle for the U.S. Marine Corps. The machine could achieve a ground clearance of nearly 12 inches without a flexible skirt and was stable even as a dozen men moved around its deck. By now, British work on even larger "hovercraft" was making international headlines, but Spacetronics' owners seemed only interested in quick stock sales. They ultimately dissolved the company and suddenly departed for Florida with the Marine Corps machine in 1960.

Crowley found a new job at American Machine & Foundry in Stamford, Connecticut, and was developing new air cushion concepts when his key corporate backer suddenly died. He was later hired by the Boeing Company and moved his family to Seattle in late 1961. It turned out that Boeing had no interest in air cushion vehicles, and Crowley found himself assigned to the Dyna-Soar and Minuteman missile programs.

On a Cushion of Air ...

While at Boeing, he developed a highly efficient air-bearing system for moving heavy objects, up to and including an entire 747 Jumbo Jet, with compressed air. Boeing backed his designs and spun off a subsidiary, Aero-Go, to commercialize the invention. He also designed a sporty air cushion scooter and a "Helibarge" in which helicopters provide the air supply to lift huge box-like platforms and 16 times their normal payload.

Walter A. Crowley left Aero-Go in the early 1970s and he and Vicki subsequently divorced. He moved to Oak Harbor, Washington, joined the Jehovah's Witnesses, and later married Lily, a coreligionist and widow. He went to work for the Island County road department as an engineer before retiring permanently in the 1980s. Crowley continued to experiment with new air cushion designs for boats and aircraft, and in addition began tinkering with magnetic levitation -- continuing his quest for flight without height. Walter Crowley died on May 29, 2008.

Sources: Adam Woog, Sexless Oysters and Self-Tipping Hats: 100 Years of Invention in the Pacific Northwest (Seattle: Sasquatch Books, 1991), 169-173; and Walter A. Crowley's archives.
Note: Walt Crowley (1947-2007), the author of this piece, is Walter A. Crowley's son. This biography was updated on May 30, 2008.

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