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 Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. I ...
. 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 rules, including the category's maximum empty weight of . The aircraft has a standard empty weight of . It features a
high-wing supported by
dihedral stabilizers, a single-seat, open cockpit,
tricycle landing gear 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 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 pilot is accommodated on an open seat bolted to the same tube. The
Cuyuna 430 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