Everett Parawing

William J. Everett Jr. filed for patent the "Gliding Parachute" on February 13th, 1967. Patent 3428277 was granted on February 18th, 1969. Everett was associated with the Pioneer Parachute Company of Manchester, Connecticut. Pioneer Aerospace obtained a license to manufacture parawings from NASA.

The below drawing is figure 3 from the patent. It shows a wing similar to a NASA parawing model 5. The rounded nose of the model 5 is replaced by ram air inflated pockets on the nose, and control lines are added to control the nose section.

patent 3428277 figure 3

Angle of attack is one of the most critical factors in achieving a high lift to drag ratio. However, simply reducing the angle of attack in a standard parawing causes the nose to collapse. The idea behind this alteration is to utilize a small ram air inflated section which would prevent nose collapse at low angles of attack.

The patent text claims an attack angle of 15° for the above model, with a resulting lift to drag ratio of "approximately 3.7 or more."

The patent describes variations to parawing planform. Below, figure 10 shows a parawing with multiple center panels. The patent intends to cover all variations of parawings, the key design element being the addition of ram air chambers in the nose.

patent 3428277 figure 10

Several enhancements to the basic nose air chambers are also described. Figure 14 below shows 3 of them on a single keel parawing variation:

patent 3428277 figure 14

This patent has many enigmatic aspects, among them:

The idea to use ram air to prevent nose collapse has been re-invented more than once. For example patent 4243191 "Hooded Kite", granted January 6th, 1981, appears to use exactly this idea to prevent a sled kite's nose collapse at low angles of attack. The "Hooded Kite" patent does not reference the Everett patent.

Related pages:
NPWC Foil Nose

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©2007 Bill Ola Rasmussen