P-791
The hybrid airship demonstrator was given the
identifier P-791. The company-funded demonstrator, which is 123 feet
long, fifty-three feet wide, and thirty feet high, was built in 2005.
First flight came on 31 January 2006. All of the major components —
cockpit, engines, fuel lines, control surfaces, ACLS pads — are attached
on the outside of the envelope. The envelope is woven Vectran, a
lightweight, high-strength material similar to Kevlar. The engines and
propellers are mounted on aluminum rings that allow vectoring up and
down and left and right for climbing, descending, and steering. The
forward engine mounts are lashed to the envelope, while the two aft
engines are attached with a composite, wishbone-shaped assembly that
fits along the contours of the envelope. The engine/propeller/mount
combinations, called thrusters, give P-791 a top speed of about thirty
knots.
|