November 2018 FLYPAST 21BOULTON PAUL DEFIANT 100 YEARS OF THE ROYAL AIR FORCE
secret was out of the bag, the
Germans would be quick to develop
countermeasures and the advantage
would soon be lost. Should both
technologies be used simultaneously,
or should one be held in reserve,
for use at some unspecified time in
the future?
The first notion was resolved only
after a frank exchange of views by
senior commanders with a vested
interest. An initial plan to create a
new squadron at Northolt,
Middlesex, was overruled in favour
of creating a smaller ‘flight’ with an
initial strength of nine aircraft
commanded by an experienced
flight lieutenant.
The second question similarly
prompted fierce debate. Douglas
became a keen advocate of
Moonshine. On May 18, 1942 he
wrote: “We are at present engaged in
offensive fighter operations against
the enemy across the Channel. It
would be to our advantage toemploy Moonshine at the first
opportunity.” He got his way.
Douglas was more circumspect
regarding the use of Mandrel. He
took heed of the warning issued to
him by Sir Henry Tizard at the
Ministry of Aircraft Production,
who wrote: “By using Mandrel we
shall be teaching him [the enemy] a
form of jamming which would be
most effective against us, and no
countermeasure is likely to be
available for a long time.”
On June 13, Douglas replied he
would not use Mandrel: “...until a
big operation comes along that
would justify giving it away. I
doubt if I shall in fact use it until
the spring.”DEFIANT FLIGHT
Moonshine had been cleared for
use. There was agreement on the
new flight, where it was to be based
and that the equipment should be
fitted to Boulton Paul Defiants. Test
flights were carried out towards the
end of May; RAF pilots flew with
civilian scientific engineers in the
rear turret where the equipment
was installed. On May 28, 1942,
Defiant Flight was formed at
Northolt and the experienced Flt Lt
Samuel Thomas DFC took command
on June 20. (The unit was also
referred to as the Special Duties
Flight Northolt.)
Experimental sorties continued
throughout June and July, as the
Flight’s strength increased in ones or
twos, as pilots and air gunners were
posted in from various OTUs and
other training establishments. Many
of the gunners in particular were
veterans who had come throughsight of a German fighter obliged
them to return home.
By using nine aircraft, each with
their designated orbit, a 200-mile
screen could be made in the German
radar coverage – a gap big enough to
allow a steady stream of bombers to
progress to their target, without the
enemy realising they were there.
FIERCE DEBATE
The challenge was to discover if the
theories of the ‘boffins’ held true
in practice and, if so, to convince
Bomber Command chiefs. Two
debates needed settling: What kind
of unit was required to deploy the
new equipment, and how might it
best be deployed?
Moonshine and Mandrel were new
and untried and would afford the
RAF a competitive advantage, but
just for a limited period. Once the
Above
A Defi ant Mk.II of 515
Squadron, formerly
known as the Defi ant
Flight or Special
Duties Flight. ANDY
HAY/FLYING ARTLeft
Lionel Anderson,
a pilot with 515
Squadron. His
younger brother
Gerry would
eventually create
the TV show
‘Thunderbirds’.Left centre
Defi ant pilot Harry
Whitmill survived
a bale-out on
April 3, 1942.