Fly Past

22 FLYPAST November 2018

1918 2018

“Moonshine and Mandrel would afford the RAF a

competitive advantage, but only for a limited period. Once

the secret was out of the bag, the Germans would be quick to

develop countermeasures...”

Above

A fl ight of 515

Squadron Defi ant

Mk.IIs. The two on the

right are AA578/K

and AA652/B. KEC

OPERATION JUBILEE

Tactics were simple: The Defiants

flew to within 35 miles of the coast

and then the gunners switched on

their transmitters and waited for

the enemy reaction. As soon as the

Germans took the bait, the Defiants

turned around, dived for the deck

and returned home at full speed.

Escort aircraft would carry out their

own duties independently.

The purpose was for the spoof force

to keep German fighters away from

the real bomber force, regardless of

its size.

Defiant Flight undertook an

important role on the morning of

August 19, 1942 in support of

Operation Jubilee, the attack on

Dieppe. Nine aircraft attempted to

draw the German day fighter force

away from where the action was really

taking place. Despite their best

efforts, this was one of the worst days

for the RAF, in which the junior

service lost 100 aircraft to enemy

action or accidents, with a further

66 damaged.

After the disappointment of

Dieppe, the flight recorded its most

successful operation on the morning

of August 21 when, along with three

fighter wings, it provided a diversion

for an attack on Rotterdam, ‘Circus

207’. More than 100 German

fighters were steered towards the

spoof, allowing the genuine force a

safer run to the target.

Defiant Flight formally became 515

Squadron on October 1. Sam

Thomas was appointed its first officer

commanding and the unit moved to

Heston, also in Middlesex, on the

29th of that month. Moonshine had

served its purpose.

MANDREL DEPLOYED

Long held in reserve, Mandrel was

cleared for action and 515 Squadron

assigned a new role and tactics. In

the late afternoon, aircraft would

leave Heston for other RAF stations

nearer to the ultimate patrol areas:

Coltishall, Norfolk; Tangmere,

Sussex; and West Malling in Kent

were preferred.

The Defiants would refuel at the

forward bases, take off in the early

evening and be guided to their

designated areas by specialist

controllers within Fighter Command.

If all went well they would land two

hours later, at the edge of their

endurance, and fly home the

following day.

It was not without danger, though.

Once the Defiant crew reached its

patrol area, the gunner had to drop

down inside the fuselage to operate

the Mandrel set and keep the dial on

the correct Freya frequency. The

Defiant was effectively defenceless

while he did so; the turret was

unmanned and the ground

controller was not able to warn his

charge of any incoming enemy

fighters in case it interfered with

the jamming.

The squadron was ready for its first

Mandrel operation on the night of

December 5-6, 1942. At just before

six in the evening, the CO set off for

the 20-minute ‘hop’ down to West

Malling, in company with his deputy.

the Battle of Britain and even the

Battle of France, and some had

been decorated.

The first opportunity to use

Moonshine operationally came on

August 6, but the sortie was

abandoned when one of the nine

Defiants suffered engine failure.

Another nine took off later that

day, in the early evening, and this

time they successfully completed

their task.

Orbiting over Portland, it was

estimated the Defiants were within

range of German radar for about an

hour before returning to base. The

enemy reacted to this intrusion by

raising the balloon barrage at

Cherbourg and launching every

fighter available in that sector from

the airfield at Maupertus.

An operator in ‘Y’ Service (a chain

of intercept stations across Britain),

listening to German radio traffic,

said post-war: “The Moonshine

Defiants laid a spoof over the

Thames that allowed US Flying

Fortresses to attack Rouen. The

Luftwaffe sent 144 planes to

intercept the spoof but only a small

number to Rouen.”

These first operations were all

undertaken in daylight and at great

danger to the crews, who had to fly in

formation for maximum effect. Each

Moonshine transmitter could only

cover a part of the Freya radar’s

frequency, but just eight or nine

Defiants were required to give the

impression of more than 100

aircraft, sowing confusion among the

enemy defences.