|
Ivan SHAW's 'Twin-EZ'
Type: twin-pusher two-seat sportsplane
Powerplants: 2 x 75-77 hp 3-cylinder
2-stroke Hewland
HAE75 engines
2
x 90 hp Norton rotary engines
Significant date: 29 June 1989 (first
flight)
The Twin-EZ was developed and built
by Mr. Ivan Shaw, a British science school teacher who basically
dreamed of modifying his Rutan pusher in
the image of the futuristic Beech Starship. The Twin-EZ started
life as a homebuilt Rutan VariEze certified
in 1978.
When Shaw considered transforming his aircraft into a twin-pusher
(initially referred to as the Twin Speed)
in 1981, he planned to use two 50 hp Lotus rotary engines.
According to him, twin pusher engines and a retractable undercarriage
should boost
the Long-EZ's cruise speed to 200 m.p.h. and increase range
to 2,000 n.m., offering 50 m.p.g. fuel economy. "No other
light aircraft will be able to touch it," claims Shaw,
a self-confessed "eyeball engineer" who aimed to
fly his home-built late in 1985 when a pair of Lotus microlight
engines would become available.
Shaw complained that the standard
Long-EZ was a "high technology airframe powered
by a low technology engine". The recommended engine was
a 100 h.p. unit made by Rolls-Royce, Continental, or Lycoming,
while Shaw claimed a pair of 50 h.p. Lotus engines weighed
701 lb. less than either of the other units and burned 20 per
cent less
fuel.
He built a bracket which allowed the pair to be attached
to the standard engine mount on the rear fuselage, each engine
sitting just 31 in. from the fuselage centre line.
Electrical systems could be run from either engine, offering "complete
redundancy". "I can't see why anyone
would fit a Lycoming when the Lotus engines become available,
offering twin engine reliability," he
added.
Shaw's other modification was to fit a fully retractable undercarriage.
This carried a 301 lb. weight penalty over the fixed undercarriage,
but reduced drag and so offered the prospect of the major
speed increase Shaw was predicting. Empty weight was predicted
to
be 800 lb. and the first flight was to be made within six
weeks of engine delivery.
However,
development of the Lotus engine type was stopped, and therefore
none was ever installed on the Twin-EZ. For Shaw,
who had worked with Lotus
and Rutan on
the Microlight aircraft,
Colin Chapman's untimely death also signified the end of all
aviation activity for Lotus, engines included. As a result
Shaw decided to modify the aircraft with larger Long-EZ wings
to accommodate two 77 hp Hewland HAE75 three-cylinder
two-stroke reciprocating engines,
installed in a pusher
configuration. In this form, the Twin-EZ was
first flown on June 29, 1989, and was
demonstrated days later at the
UK Popular Flying Association's
annual rally at Cranfield Airport.
The
Twin-EZ was soon used as test-bed for the Norton-Wankle
NR642 rotary
engines, each
unit being mounted pusher-style at
the wing trailing edge. The Norton rotary engine
had already been tested in 1987 in an Aviation
Composites Mercury,
a local derivative of the Microlight developed at
Scaled Composites. The advantages of the rotary Norton
over the Hewland engine were
said to be a lengthy overhaul interval and increased power.
The latter would improve performance and allow a higher
gross
weight.
The Norton engine developed 90 h.p. compared with the Hewland's
75 h.p., and was claimed to be extremely light for its power
output owing to constructional simplicity.
The history of the Twin-EZ after that is not quite
clear, but the aircraft is still on the British register to
this day, and now belongs to Anthony
Malcolm. Chances are it has long been reverted to a more or
less standard
Long-EZ configuration.
After Shaw set up his own business in July 1985, Inav (Innovative
Aviation, Ltd) — a
new wholly
owned subsidiary of
Britain's Aviation Composites — established to purchase
the assets of Monnett Experimental Aircraft, Inc (MEA), he
eventually met with
success
when he launched
the Europa light
aircraft in the late 1990s, arguably the most successful kit
aircraft manufacturer in the world, which itself became the
basis for the Liberty
XL-2,
testifying to his long-term work relationship with Scaled.
Population: 1 (c/n 39; s/n PFA 074-10502)
[G-IVAN]
Specifications:
Cruise speed: 280 mph
Dimensions: probably very similar to those of the Long-EZ
Crew/passengers: 2
Main sources:
- Flight International, 7 September 1985
- Flight
International, 15 July 1989
Many thanks to Walter
van Tilborg for providing the basis for this article.
|