The Aviation Historian — January 2018

Issue No 22 THE AVIATION HISTORIAN 95

T

HE SERIES OF photographs presented

here, most previously unpublished,

taken by an unknown photographer

and from the collection of the late John

Havers, shows part of the early testing

programme for the Westland Wyvern naval strike

fighter. The Wyvern suffered a particularly protracted

development, owing to the complexity of the aircraft

and the number of new elements combined into one

package, not to mention changes of powerplant. As

such, it is a particularly fascinating glimpse into the

first months of a programme that would last more

than six years before the aircraft was finally cleared for

service use in April 1954.

The Eagle and the Python

The Wyvern was a large propeller-driven strike aircraft

conceived towards the end of the Second World

War. Specification N.11/44 was issued on January 1,

1945, solely to Westland, which had been working on

various configurations of heavy naval fighter to take

advantage of new and more powerful engines then

under development.

Westland had developed its initial designs with

the large Rolls-Royce Eagle 24-cylinder sleeve-valve

engine in mind (including some configurations with

a mid-set engine and long shaft-mounted propeller).

However, the possibilities offered by the embryonic

“propeller turbine” — or turboprop — were becoming

apparent, and N.11/44 specified the option of a

turboprop instead of the Eagle. The Wyvern would

eventually be powered by one of these, namely the

Armstrong Siddeley Python (then under development

as the ASP), but the first prototypes were powered by

the Eagle, almost as experimental as the turboprops,

and which incorporated numerous new design features

for the company.

The first N.11/44 (it was not formally known as

ABOVE As Westland’s factory at Yeovil

was not suitable for the Wyvern’s early

test flights, much of its development

flying was undertaken from Merryfield.

Here we see TS375 in front of a T2

hangar, with engineers working on the

complex Rotol propeller. Only the rear

blades are yet in place; the apparatus to

lift the front blade unit into place

may be seen to the left.