BLACKBURN ROC BATTLE OF BRITAIN COMBAT

26 September 1940

The combat claims made by the RAF during the summer and autumn of 1940 were in the main made by Hurricanes and Spitfires with a few by the twin-engine Blenheim and turret-armed Defiant. The Defiant's naval equivalent was the Blackburn Roc, named after the gigantic bird of Eastern legend, which was based on the Company's earlier Skua dive bomber. It was unsuccessful and saw only brief front line service with the Fleet Air Arm before being passed to second line units. Some were transferred to the RAF and in the summer of 1940 joined No. 2 Anti-Aircraft Co-operation Unit (AACU) which was based at Gosport in Hampshire - right in the front line of the Battle of Britain.

Following an attack on the airfield by Junkers Ju 87B Stukas on 18 August 1940, 2 AACU was ordered to disperse four of its Rocs, with their turrets fully armed (they were usually unarmed), around the airfield for anti-aircraft defence. They were also to hold standby for fighter defence, though it took some time to fully equip them with guns and radios. However, by 8 September two Rocs were operational and the following day one of them, L3085, was allocated to Pilot Officer D. H. "Nobby" Clarke who chose Sergeant Mercer as his gunner.

The ebullient Clarke personalised his camouflaged machine with a red "Saint" within a red framed yellow diamond on the fuselage. Clarke's Roc was declared operational on the 12th and after every anti-aircraft cooperation sortie he and Mercer harmonised the guns and trained for more warlike work.

On 24 September the Luftwaffe bombed the Spitfire factory at Woolston; two days later the Supermarine works was attacked by a large force of Heinkel He 111s that extensively damaged parts of the vital site. During the late afternoon fighting, several defending Hurricanes - two from 238 Squadron and one of 607 - were shot down off the Isle of Wight. There had also been German losses resulting in their efficient air-sea rescue service sending out aircraft looking for their downed airmen.

At 17.30 hours, 2 AACU received a call ordering it to send an aircraft to search for downed airmen fifteen miles south-west of St Catherine's Point on the Isle of Wight. Clarke, with Sergeant Hunt as his gunner, was airborne in L3085 and, within fifteen minutes of the call, was heading for the search area.

In the increasing gloom of the evening Clarke and Hunt searched over the grey sea for three-quarters of an hour, when Clarke noticed what he took to be a Swordfish seaplane in the distance. Puzzled by its appearance and apparent size, he closed and seeing its camouflage and large black crosses realised that it was in fact German! The Roc crew had come across a Heinkel He 59 seaplane (probably of Seenotflugkommando 1) which was also engaged on an air-sea rescue search.

As Clarke approached, the Heinkel's gunners opened fire and hit the Roc's port wing. Hunt responded. However, the Roc's guns could not depress so Clarke was forced to fly at zero feet below the low flying seaplane.

"Diving slightly from 500 feet," he recalled, "I overhauled him rapidly and commenced the turn as soon as I was level with the nose. Hunt opened up; I saw our tracer pouring into the enemy's fuselage and wing centre section."

Time and again the faster Roc passed the seaplane with Hunt firing brief bursts from his four Browning machine-guns as he did so. The seaplane was hit but its gunners were also striking the Roc and as the French coast approached a frustrated Clarke was forced to break off and head back to Gosport. It was a prudent call as he was short of fuel and the Roc's engine stopped soon after landing.

The enemy fire had been accurate and ten hits were found on the Roc, including two (fortunately) unexploded incendiary rounds in the fuel tank. In his combat report, in what was probably the strangest air combat of the epic Battle of Britain, "Nobby" Clarke put in a claim for one He 59 seaplane damaged - the only claim made by a Roc during the Battle.

Airthief’ operation

Armin Faber's Focke-Wulf Fw 190A-3 of III/JG 2 at RAF Pembrey, June 1942.

By the spring of 1942 the Fw 190 had become an uncomfortably sharp thorn in the side of RAF Fighter Command. Obviously, if an airworthy example of the Fw 190 could be captured and its secrets probed, that would be of inestimable value. Capt. Philip Pinckney, a British commando officer, hatched a daring plan to gain that end.

In an operation of this type, two men might succeed where more might fail. Pinckney suggested that his good friend Jeffrey Quill, chief test pilot at the Supermarine Company, should accompany him on the enterprise.

The essentials of the plan were as follows. On Night 1 a Royal Navy motor gunboat, equipped with direction-finding radio, was to carry the pair to a point within about two miles of a selected beach on the French coast, where they would disembark into a folding canoe. The pair would paddle ashore, hide their boat in sand dunes and lie up during the following day. On Night 2 the pair would move inland to within observation range of the selected Fw 190 airfield, and hide up before dawn. During the daylight hours the pair would keep the airfield under observation and plan their attack. On Night 3 the pair would penetrate the airfield defences by stealth, and conceal themselves as near as possible to one or more Fw 190s at their dispersal points. The pair would then wait until the next day, when the ground crew arrived to run the engine of one of the fighters.

The pair would then break cover, shoot or drive away the ground crewmen, and Jeffrey Quill would jump into the cockpit and taxi the machine to the runway. As he did so, Pinckney would be outside the plane warding off any attempt to interfere with the operation. Once Quill was safely airborne, Pinckney would withdraw to a previously prepared hide. On Night 4 he would return to the hidden canoe. Just before dawn he would launch the craft and paddle out to sea, making radio transmissions so that the motor gunboat could home on the craft and pick him up.

Yet in a remarkable coincidence, on the very day Pinckney submitted his proposal, the need for this risky operation disappeared. On the afternoon of 23 June an Fw 190 pilot had become disorientated in a dogfight with Spitfires over southern England. He mistook the Bristol Channel for the English Channel and made a wheels-down landing at Pembrey airfield, south Wales [above]. Thus, the RAF gained the coveted example of an Fw 190, without having to resort to the risky ‘Airthief’ operation.

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 By the beginning of 1942 it was clear that the capture of an airworthy Fw 190 would be of inestimable value to RAF Fighter Command. Yet in wrtime the aquisition of an example of the latest enemy fighter in an undamaged condition was a requirement far easier to state than to achieve. Nevertheless Captain Philip Pinckney, a Commando officer who was undeterred by the many obvious difficulties, put forward a proposal for 2 men to attempt to achieve by stealth what a battalion would not achieve by force: to steal one of the new German fighters and fly it back to England. For sheer effrontery the plan, which is reproduced in full below, can have few equals in military history. And it might just have succeeded.

MOST SECRET AND URGENT
To: Officer Commanding No 12 Commando
From: Captain Pinckney, E Troop, No 12 Commando

Sir,
I understand that as a matter of great urgency and importance a specimen Focke Wulf 190 is required in this country. I attach a proposal for procuring one of these aircraft.
....I have the honour to request that this, my application to be allowed to undertake the operation described, may be forwarded as rapidly as possible through the correct channels to the Chief of Combined Operations I further propose that the pilot to accompany me should be Mr. Jeffery Quill who is a close friend of mine, and as a well known test pilot of fighter aircraft is well qualified to bring back the plane. He is also young, active, a yachtsman, and a man in every way suitable to carry out the preliminary approach by land and sea.
....If Mr. Quill cannot be allowed to undertake this operation, perhaps a substitute could be made available from the Free French Forces. I am most anxious to be allowed to volunteer for this operation.

I have the honour to be
Sir
Your obedient servant
(signed) P. H. Pinckney

23.6.42

1) Object: to bring back to this country undamaged a Focke Wulf 190
2) Forces Required:
One MGB (motor gunboat) equipped with DF (direction-finding radio) apparatus, to carry a folbot (collaspable canoe) to within 2 miles of the coast of France.
One folbot equipped with wireless transmitter.
One officer of a Commando.
One specially selected pilot.

Method
3) Day 1
a) On the night of D1, the MGB, carrying the officers and folbot, will leave England after dark and proceed at best speed to within 2 miles of the French coast off a selected beach.
b) On reaching the beach the folbot will be carried inland and hidden in a wood or buried in the dunes. The officers will lie up during the following day.

4) Day 2
After laying up all day the officers will move inland until they are within observation range of a fighter aerodrome.

5) Day 3
a) On D3, the officers will keep the aerodrome under observation and plan the attack for the start of nautical twilight (ie, just before sunrise) on D4.
b) During the night of D3, the officers will penetrate the aerodrome defenses by stealth and will conceal themselves as near as possible to a selected Focke Wulf aircraft.

6) Day 4
a) At the start of nautical twilight on D4, when the aircraft are warmed up by the ground mechanics, the two officers will take the first opportunity to shoot the ground mechanics of the selected plane as soon as it has been started up. The pilot officer will take off in the machine and return to England. The commando officer will first ensure the safe departure of the aircraft and will then withdraw to a previously reconnoitred hideup. Should no opportunity to seize the aircraft have presented itself, the officers will withdraw to a hideup and make another attempt the next morning.
b) During the night of D4, the commando officer will return to the concealed folbot.

7) Day 5
a) After nautical twilight of D5 ot during the succeeding night, this officer will launch the folbot and be picked up by an MGB.
b) The MGB should be off the coast for two hours before nautical twilight on D5, D6 or D7 providing the weather is calm. If the weather is unsuitable, the Mgb should come on the first suitable morning. The ooficer after launching the folbot will paddle to a pre-arranged bearing. the MGB, making due allowance for the day and consquent set of the tide, will proceed on a course to intercept the folbot. In addition the officer will make wireless signals, which will be picked up by the MGB using DF gear.

Notes
Selected Aerodrome:
a) The selection of an aerodrome will be dependant on intelligence not at present available to me. The requirements are:
1)Within 20 miles of a landing beach which is not too strongly defended, and which has a hinterland of dunes or woods offering a hiding place for the folbot.
2) Within observation range or a few miles of a covered approach or a wood or place of concealment.

b) It is thought that possibly Abbeville aerodrome might be suitable with a landing made on the Somme Estuary. The Cherbourg peninsula, entailing a cliff-climbing onlanding, might give a good chance of making an undiscovered landing, providing a suitable aerodrome is nearby.

9) Return of the Plane:
Arrangments must be made with Fighter Command to ensure that the pilot officer is not shot down by our fighters on returning with the aptured aircraft. It is suggested that these arrangments should not be dependant upon wireless or on the officers taking distinctive markings or signalling aparatus with them. Possibly Fighter Command could be instructed not to shoot down any enemy Focke Wulf 190 appearing over the coast during specified times on selected days. In addition the undercarriage could be lowered for identification. If a Focke Wulf 190 after all is unprocurable on the aerodrome, a Messerschmitt 109F could be brought back instead. I understand that its aquisition would also be valuable.

10) Date:
The landing should be made on a rising tide to cover footprints and also on a dark night to achieve surprise.

11) Alternative Return of Commando Officer:
If it is considered an unacceptable naval risk to bring back an MGB to pick up the Commando officer, this officer could either paddle on a course pre-arranged by Fighter Command and eventually be picked up by an RAF rescue launch or, as a third alternative method of withdrawl, he could be instructed to make his way back through occupied France.

12) Other Considerations:
a) Food. the officers will be equipped with 10 day's compressed rations.
b) Preparation. The officers should have ample time to train together for a period which need not exceed 10 days. Training should also be carried out on the MGB.
c) Security. The officers suggested in the covering letter accompanying this proposal are both at present stationed at Bursledon, where they frequently go sailing together; the Commando officer owns a double folbot which is used daily; there are MGBs stationed at Bursledon; training could therefore be started without delay without arrousing any suspicions that an operation was under rehearsal.

Pinckney's proposal was allocated the operational code-name "Airthief" and detailed planning began; the airfield at Cherbourg-Maupertus was considered suitable for such an enterprise. Yet while still in the embryo stage, "Airthief" was overtaken by a coincidence more bizarre than any fiction writer would devise. On the very evening after Pinckney submitted his paper, on 23 June 1942, a German pilot became disoriented during a fight with Spitfires over southern England and inadvertantly landed his Fw 190 at Pembrey in South Wales. So the RAF got its Focke Wulf, without having to resort to "Airthief".

Philip Pinckney did not survive the war; he was killed in action in Italy in 1944. Of the chances of success of "Airthief", Jeffery Quill commented, "Provided we could get to the aircraft with its engine running, get the German airman out of the cockpit dead or alive and get me into it, I thought I had a 50-50 chance of getting back to England. As to the early part of the operation I was not qualified to have a view and I was guided entirely by Philip who seemed very confident and I would just have done what he said. He ws obviously relying on stealth - and perhaps we might have got away with it. Philip was always evasive about his own plans for getting back. I had a splendid way of getting back by air, but it was a very different kettle of fish for him. But he was very resourceful and might well have made it, one way or another, provided I had got the aircraft off the airfield without too much of a hue and cry.

Anyway it was a non-event, as it turned out. Philip Pinckney was the inspiration behind the whole thing. Had it succeeded it would have been 90% due to him and the balance of danger would have been heavily against him. I think he was bitterly disappointed when it was called off and he was quite cross about the German pilot landing in Wales. I am afraid I have to confess to a certain easing of tension within my guts!"

Instruments of Darkness

THE "BERNHARD/BERNHARDINE" SYSTEM

LORENZ

A prewar, civilian radio beam navigation system adapted as a bomber aid by both the RAF and Luftwaffe. It comprised a radio signal broadcast by the airfield and received passively by approaching aircraft. It had a limited range of about 20 miles. Its main importance was to aid wartime development of the Knickebein and X-Gerät beam systems.

KNICKEBEIN

A Luftwaffe electronic navigation aid for night bombers in which two directional radio beams were broadcast to intersect over a target in Britain. The bombers followed one beam—guided by Morse dots and dashes—until it met the second, then released their bomb load. It was an advance in both range and accuracy on the prewar Lorenz blind-landing system used by civil aviation. By July 1940, the RAF developed a counter, code-named “Aspirin,” which imposed a British beam atop the German beam in a process called “bending the beam,” although the German beam was never actually “bent.” The Luftwaffe next moved to the X-Gerät system, as the “battle of the beams” continued.

ASPIRIN

The centrepiece of the British Electronic Counter Measures (ECM) effort was however ‘Aspirin’, a high power transmitter which emulated the signals from the dot modulated lobe of the Knickebein. This had the effect of confusing German pilots, who even when centred in the Knickbein beam would hear the dots emanating from the Aspirin jammer. By October 1940 the British had deployed fifteen Aspirin jammers to frustrate the Knickebein system. The stakes were high. Estimates of the accuracy of the Knickebein suggested that it was capable of putting a 300 m x 300 m box around an intended target, which when saturated with bombs from a mere 40 aircraft would put the bombs down on average 17 metres apart.

X-GERÄT

A sophisticated Luftwaffe beam navigation system. It was derived from the prewar Lorenz and early wartime Knickebein systems, which the RAF successfully countered by July 1940. X-Gerät used four beams and a bomb-release mechanical computer that was triggered by passing over the three cross beams. It was deployed by a special target-marking unit of the Luftwaffe, which then dropped flares and incendiaries to mark the target for follow-on bombers.

BROMIDE

The British built the ‘Bromide’ jammer, using radar hardware, to defeat the X- Gerät system. While the Bromide equipment was being developed, KG.100 conducted no less than forty raids using X- Gerät. These raids were essentially an ‘Opeval’ to determine the limits of the system and to develop tactics. KG.100 started dropping incendiaries, a tactic to mark targets for a larger bomber force. This was the origin of the pathfinder technique later used by the RAF to obliterate German cities.

Y- GERÄT

By early 1941, the X- Gerät was losing effectiveness, along with Luftwaffe command confidence in the system. The Luftwaffe was, however, deploying a third radio bombing aid also designed by Dr Plendl, named Wotan II or Y- Gerät. Y- Gerät used a similar but automated scheme for bomber heading tracking, but used a beacon transponder arrangement for measuring range between the Y- Gerät station and the bomber. Not unlike a ‘back to front DME’, the Y- Gerät station operators could track the bomber’s position and send by radio course corrections to the pilot.

DOMINO

The Luftwaffe was less fortunate with Y-Gerät than with the previous two systems. The British requisitioned a mothballed experimental BBC television transmitter at Alexandra Palace in North London, and adapted it to rebroadcast the Y-Gerät rangefinding signal. Labelled the Domino, the Y-Gerät jammer was soon followed by a second installation at Beacon Hill near Salisbury. The RAF was effectively performing ‘range gate stealing’ jamming attacks on the Y-Gerät, to completely compromise the range measurement achieved by the Germans. The German ground station receiver would lock on to the Domino jammer instead of the Y-Gerät transponder on the bomber, and the British could then manipulate its range measurement. The Domino jammer proved effective, and in the first two weeks of March 1941 only 20 per cent of Y-Gerät raids resulted in commanded bomb releases. Three Heinkels were shot down in early May and the RAF recovered the Y-Gerät receivers. They quickly determined that the automated mechanism for measuring the bearing error in the beam was susceptible to continuous wave jamming, which crippled the bearing analyser circuit.

Time had run out for the Luftwaffe, and with the buildup for Barbarossa, the invasion of the USSR, the KampfGruppes were redeployed east and the Battle of the Beams was won by the British.

The Battle of the Beams is generally acknowledged to have been the first modern effort at electronic warfare, and was characterised by the Luftwaffe not attempting to seriously improve the jam resistance of their systems, but rather by deploying newer and more advanced systems. It remains an excellent case study of how the game of technical intelligence gathering and analysis is played, and how pivotal it is to success in modern warfare. 

Further Reading: Price A, Instruments of Darkness, Peninsula Publishing, 1987.