The Waspair HM 81 Tomcat is a British

canard Canard is French for duck, a type of aquatic bird. Canard may also refer to: Aviation *Canard (aeronautics), a small wing in front of an aircraft's main wing * Aviafiber Canard 2FL, a single seat recreational aircraft of canard design * Blé ...

ultralight aircraft Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailer ...

of unusual design, that was produced by Waspair and later Midwest Microlites. The designer is disputed and Chip Erwin, Larry Whiting and Robin Haynes are all named as designers. The aircraft was supplied as a kit for amateur construction.Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page E-28 and E-41. Cybair Limited Publishing, 2001.

Design and development

The aircraft was designed to comply with the US

FAR 103 Ultralight Vehicles Ultralight aircraft in the United States are much smaller and lighter than ultralight aircraft as defined by all other countries. In the United States, ultralights are described as "ultralight vehicles" and not as aircraft. They are not requ ...

rules, including the category's maximum empty weight of . The aircraft has a standard empty weight of . It features a

high-wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

supported by dihedral stabilizers, a single-seat, open cockpit,

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle g ...

and a single engine in

pusher configuration In an aircraft with a pusher configuration (as opposed to a tractor configuration), the propeller(s) are mounted behind their respective engine(s). Since a pusher propeller is mounted behind the engine, the drive shaft is in compression in nor ...

. The aircraft structure is made from

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

tubing. Its span wing sits high above the pilot's seat, providing pendulum stability. The controls are very unconventional and all are canard mounted, which has two surfaces. The canard surfaces move in unison to produce pitch and separately, in opposite directions, to produce roll. The large fixed dihedral stabilizers provide yaw control as the wing has no dihedral of its own for yaw coupling. The canard surfaces are mounted to the front of the main keel tube, which serves as a

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

. The pilot is accommodated on an open seat bolted to the same tube. The

Cuyuna 430 The Cuyuna 430 and Cuyuna 340 are a family of two-stroke, twin-cylinder piston snowmobile engines that were redesigned to serve as ultralight aircraft powerplants.Cuyuna Development Company: ''Cuyuna Engines'', Cuyuna Development Company, undat ...

powerplant is located behind the pilot. In service the control system has proved inadequate and the aircraft is difficult to control in flight, particularly in air that is not smooth and there have been a number of loss-of-control accidents. The Virtual Ultralight Museum describes the aircraft as "ungainly and unstable". Reviewer Andre Cliche says of the Tomcat's handling characteristics: Cliche recommends that Tomcats be scrapped for parts and not flown. An improved model, the Pintail, was later introduced by Haynes, which has control surfaces on the trailing edge of the dihedral stabilizers, but it is unclear if this fully addresses the original design's deficiencies.

Variants

;Tomcat Standard :Initial version with two-axis controls ;Tomcat Sport :Improved version with two-axis controls ;Tomcat Tourer :Two seat model with two-axis controls ; Haynes Pintail :Improved version with three-axis controls

Specifications (Pintail)

References

{{reflist

External links

Image of the TomcatTomcat in flight
1980s United States ultralight aircraft Homebuilt aircraft Single-engined pusher aircraft