Aeroplane – June 2018

INSIGHTS FAIREY ROTODYNE

View from the cockpit

A low-level

demonstration of

Rotodyne agility. Once

experience had been

gained, Ron Gellatly

had much praise for

the machine’s flying

qualities. LEONARDO

T

he Rotodyne could

operate in two basic

modes. Relying on its

rotor for control and,

with engine power providing

thrust for forward flight, it was a

pure helicopter, but with no

direct drive to the rotor and

forward thrust provided by the

propellers, it was an autogyro.

The take-off sequence was

initiated by starting the engines

and engaging their auxiliary

compressors to enable air to

flow to the tip-jets. The rotor

was then allowed to accelerate

to the normal light-up speed of

100rpm. With fuel cocks and

ignition selected on, light-up

generally took five to 10

seconds to achieve. With the

tip-jets burning the rotor could

then be accelerated to flight

speed of 140rpm.

Taking off in helicopter mode

meant that, with the rotor

powered by the tip-jets, the

pilot was controlling the aircraft

in pitch, roll and hover using

the cyclic pitch control. Lift

control was maintained through

the collective pitch lever, and

yaw control through differential

propeller pitch.

Once airborne the Rotodyne

could achieve forward flight like

a helicopter, with the tip-jets

powering the rotor which was

controlled through the

collective and cyclic control

levers. Yaw control was exerted

through application of

differential propeller pitch but,

as the aircraft’s speed

increased, the machine

increasingly came under the

aerodynamic influence of the

rudders.

For maximum safety in

service, and to minimise noise

disturbance, Rotodyne flight

paths would have required a

vertical climb to 2,500ft (790m)

before the aircraft accelerated

in forward flight through a

point 6,000ft (1,850m)

overhead the heliport. For

landing the standard approach

angle would have been 5°.

9696 http://www.aeroplanemonthly.comwww.aeroplanemonthly.com AEROAEROPLANE PLANE JULY 2018JULY 2018

It achieved forward flight like a helicopter, with

the tip-jets powering the rotor which was

controlled through the collective and cyclic

85-100_AM_Database_July18_cc C.indd 96 04/06/2018 17:00