Design & Construction

Weight

The design challenge in small airships is weight. Lighter the airships the smaller it can be. A small airship will require less helium, smaller engines and will be easier to handle by the ground crew. Smaller airships also require smaller and less expensive hangers. Because of the light weight, all USAI airships can be disassembled by two men in one or two hours and loaded on a pickup truck or into an enclosed trailer only 14’ long.

Car

The airships car frame is constructed of certified aircraft aluminum and welded together by certified aircraft welders. Designed to be lightweight yet strong, the weight of the car frame is only 100 lbs. All except the UL1-B model have a car height of 6’ to allow the pilot and passenger to stand during flight. The car is open frame, but can be completely enclose for winter flying by attaching an optional lightweight cover. The car design is unique… there are no feet or wheel controls allowing the pilot to stand while flying the airship. All directional controls (rudder, elevator or tail motor vector thrust) are “fly by wire” therefore eliminating cable controls.

The main instrument panel can be accessed from the rear by the removal of a single cover. The instrument panel can be easily removed from the front in only a couple of minutes. Molded seats provide comfort and seat belts are standard. Under each seat is a storage box for personal items such as cameras and snacks. On models UL1-D and UL2-D floats are provided for water operation.

Envelope

The envelope is constructed of 9 mil polyurethane providing strength and flexibility. This material has been in use for over 15 years and has logged over 50,000 flight hours in helium filled blimps. All seams are overlapped heat sealed by a special machine designed just for the construction of USAI envelopes. The car is attached to the envelope through 26 attachments, 13 on each side of the car. The car can be disconnected from the envelope in less than two minutes by removing two rods that slide through the 13 attachments on each side of the car. The envelope material will not rip even when punctured and can easily be repaired by the owner or pilot.

Engine & Motors

The size of the main car engine and propeller vary depending on the airship model. Models UL1-B and UL2-B are rope start. Models UL1-S, UL1-D, UL2-S and UL2-D are electric start and have an alternator charging system. Models UL-1D and UL2-D have electric motors on the tail which can be moved left/right and up/down to provide vector thrust directional control of the airship (in addition to the standard rudder and elevator controls). The main propeller can be engaged or disengaged while the alternator charges the battery.

Performance

Lift

All USAI airships provide adequate lift for the pilot (and passenger on the two man models), ballast, flight gear and fuel. All models have a single air filled adjustable ballonet to help maintain the correct envelope pressure over a normal range of temperature changes. Because of the stretch ability of the envelope material the helium capacity can be increased up to 10% to provide an additional 50 to 135 pounds of lift to carry extra equipment or fuel. Extra fuel can provide long duration flights over 10 hours and 300 miles.

Maneuverability

“Fly by wire” rudder and elevator controls are standard on all models. On Models UL1-D and UL2-D electric motors on the tail provide a second “fly by wire” directional control system. The tail motors can be moved left/right and up/down providing vector thrust movement of the tail at low speeds or no speed (like when on the ground). The tail motors allow you to fly in a tight circle less than 100 feet in diameter and at speeds less than 10 miles per hour. Rudder and elevator controls are more effective at higher speeds.

Speed

Speed varies from model to model. The single man airships speed varies between 24 and 28 mph. The two man airships speed varies from 30 to 35 mph. USAI’s low speed capabilities (under 15 mph) make flying these airships fun and enjoyable. Models UL1-D and UL2-D have electric tail motors that allows you to fly with the main car engine turned off. In this mode you fly in complete silence like on a “Magic Carpet”. Why can you not hear the tail motors or props? The helium in the airship blocks 100% of the sound.

Duration & Range

Duration and range varies from model to model and is determined by the fuel capacity. The standard 5-gallon tank will provide an average duration/range up to 5 hours and 150 miles. With 10 gallons the duration/range can be over 10 hours and 300 miles.