Tom Cadet designed and built the Mk1 Boorabee in 1992. The Mk1 Boorabees flew with a Rotax 503and the first aircraft has had at least 3 different engines including an HKS fitted in 2010.
The original fuselage pod mould for the Boorabee was made from the two halves taken from a crashed Rotec Panther, then modified by making the front more pointed and taking the aft section up to the wing. Tom also added a sheet alloy floor pan. A Maxair Drifter contributed the aluminium tube boom and empennage.
Dave Donohoe, a colleague of Tom Cadet, developed the Boorabee’s airfoil. This wing was mated to a new fuselage mould to use a 4 x 3 inch rectangular boom and Dave called the result the Shuttle.
For the Boorabee’s wing, Tom used fibreglass/Kevlar ribs with a glass/Kevlar leading edge. The main spar caps are 40 x 1.6mm drawn alloy tubes with 1.2mm sheet web plates; the rear spar is a 44 x 1.6mm tube.
Boorabees are extremely docile aircraft with few if any vices. The Mk1s are really powered gliders without air brakes (better than 12:1 glide) they tend to float so it requires a special technique to spot land them.
Cadet built two Mk1 Boorabees then made new moulds and simplified the design for the Mk2.
Three versions of the Boorabee appeared. The Mk 1 has a 30ft wing span. That of the Mk 2 was reduced to 29ft, and a new mould was made to improve the shape of the fuselage pod. Alloy shear plates were used to simplify wing construction, and flaperons adopted. Kevlar was used extensively to lighten the aircraft. Both the first Mk 1 and Mk 2 were registered in 1993.
A lengthened pod, offering more foot space for the rear-seat passenger, was introduced with the Mk 3, which also had the shorter wing.
The choice of powerplant was usually the Rotax 582 or 618. A Rotax 503 was used by Bob Evans of Evans Head for his Mk 2, completed as a single seater with a more rounded tail.
There were nine Boorabees built in total before Cadet gave the fuselage plug to Dave Donohoe who modified it for a rectangular boom tube. Dave’s Shuttle shared the same wing but the boom, tail, undercarriage and controls were vastly different. Cadet loaned the moulds to persons he trusted, and gave them the CAD plans at no cost.
For several years, Tom freely provided scale drawings to those interested in building a Boorabee, the use of his moulds, and builder support. A dozen or so Boorabees were completed by local builders.
As with all pusher aircraft, the airflow around the rear of the fuselage was a problem, causing slight instability in yaw as well as reduced thrust from the propeller. After experiments on the Mk 1s a line of vortex generators on the fuselage immediately solved the issues. Because the two blades of the original propeller disturbed the air at the wing trailing edge in unison, resulting in uncomfortable vibration at certain speeds, a three-blade propeller was found to be necessary. Apart from these annoyances the Boorabee proved very successful, with hundreds of hours logged by each aircraft.
No more Boorabees were built because it required a great deal of effort by Cadet for builder assistance and it became very difficult to get the 5″ boom tube and necessary drawn tubing to build the wing. He still had the moulds years later.
The first Boorabee has flown thousands of hours.
Boorabee Mk1
Engine: HKS 700 E 60hp
Wingspan: 9.2 m / 30 ft
Length: 5.85 m
Empty Weight: 284 kg
Maximum Take Off Weight: 554 kg
Fuel Capacity: 94 litres
Never exceed: 90 Kts
Cruise Speed: 60Kts
Stall Speed: 30 Kts
Take off roll: 200 meters
Rate of Climb: 500 ft per minute
Endurance: 10 hours
Seats: 1
Mk 2
Wing span: 29 ft
Mk 3
Wing span: 29 ft
