Boulton Paul Defiant
Encyclopedia
The Boulton Paul Defiant was a British
interceptor aircraft
that served with the Royal Air Force
(RAF) early in the Second World War. The Defiant was designed and built by Boulton Paul Aircraft
as a "turret fighter", without any forward-firing guns. It was a contemporary of the Royal Navy
's Blackburn Roc
. The concept of a turret fighter related directly to the successful First World War-era Bristol F.2 Fighter
.
In practice, the Defiant was found to be vulnerable to the Luftwaffe
s more agile, single-seat Messerschmitt Bf 109
fighters. It became used as a night fighter
until it was supplanted in that role by the Bristol Beaufighter
and de Havilland Mosquito
. The Defiant found use in gunnery training, target towing, electronic countermeasures
(ECM) and air-sea rescue
. Among RAF pilots, it had the nickname "Daffy", probably a diminutive of the word "Defiant".
The concept of a turret-armed defensive fighter emerged in 1935, at a time when the RAF anticipated having to defend Great Britain against massed formations of unescorted enemy bombers. Advances in aircraft design during the 1920s and 1930s had resulted in a generation of multi-engined bombers that were faster than the single-engined biplane
fighters in service. The RAF believed that its turret-armed bombers, such as the Vickers Wellington
, would be able to penetrate enemy airspace and defend themselves without fighter escort and also that the German Luftwaffe would be able to do the same.
In theory, turret-armed fighters would approach an enemy bomber from below or from the side and coordinate their fire. The separation of the tasks of flying the aircraft and firing the guns would allow the pilot to concentrate on putting the fighter into the best position while the gunner could engage the enemy. Previously the Hawker Demon had tested the concept with 59 of the biplane fighters (manufactured by Boulton Paul under a sub-contract) equipped with a powered rear turret while the remainder of the series already manufactured were converted.
Air Ministry
Specification F.9/35 required a two-seater day and night "turret fighter" capable of 290 mph at 15,000 ft. It followed the earlier F.5/33 which was for a pusher design with a front turret. F.5/33 had been abandoned as it offered little over existing fighters and the Armstrong Whitworth AW.34 design which had been ordered was not completed.
bomber, submitted their P.82 design. Of the seven designs tendered, the P.82 was ranked second after Hawkers but ahead of Armstrong Whitworths twin-engined design. The Air Ministry wanted several designs investigated and two prototypes of each. The Treasury agreed to seven prototypes (2 Hawker, 2 Boulton Paul, 2 Fairey and 1 Armstrong Whitworth). In the event only prototypes of the P.82 and Hawker were built. Production orders were prepared for the Hawker but the Boulton Paul turret had the Air Ministry's attention. Delays by Hawker who were more focussed on the Hurricane led to the P.82 receiving a production order in 1937 and the Hotspur order was cancelled in 1938.
The P.82 was a monocque design constructed by bolting the sections together. This was the same as BP had used on other aircraft. The design had room for small bombs in recesses in the outer wing. Some of the development work from their B.1/35 tender carried over into the P.82
The central feature of the P.82 was the four-gun turret based on a design by French aviation company SAMM which had been licensed by Boulton Paul for use in the earlier Boulton Paul Sidestrand
bomber but eventually installed in the "follow-up" design, the Boulton Paul Overstrand
and Blackburn Roc
naval fighter. The turret, 'Type A' was an electro-hydraulically powered "drop-in" unit with a crank-operated mechanical backup. The Defiant was armed with a powered dorsal turret, equipped with four 0.303 in (7.7 mm)
Browning machine gun
s. The fuselage
was fitted with aerodynamic fairings that helped mitigate the drag of the turret; they were pneumatically powered and could be lowered into the fuselage so that the turret could rotate freely. The Brownings were electrically fired and insulated cut-off points in the turret ring prevented the guns firing when they were pointing at the propeller disc or tailplane. The gunner could rotate the turret directly forward and transfer firing control of the guns to the pilot, with the guns firing along each side of the cockpit canopy. However, in practice this was rarely done as the turret's minimum forward elevation was 19° and the pilot did not have a gunsight.
The gunner's hatch was in the rear of the turret, which had to be rotated to a side to enable entry and exit. There was not enough room in the turret for the gunner to wear a seat-type or back pack parachute so gunners were provided with a special all-in-one garment nicknamed the "rhino suit". To quote Frederick "Gus" Platts, air gunner in 230, 282 and 208 squadrons, "The Rhino suit we had to wear on Defiants was a bear but I couldn't come up with an alternative, even though it killed dozens of us. I forget the details of it but we could not have sat on our chute or even keep it nearby as in other turrets, so you wore – all in one – an inner layer that fitted a little like a wetsuit of today. The chute fitted around this, and then the dinghy and the outer clothing. There was inner webbing and pockets that literally fell apart (I presume) when one bailed out".
The first P.82 prototype (K8310) was rolled out in 1937 without its turret, looking like the Hawker Hurricane
, although it was at least 1,500 lb (680 kg) heavier. A clean, simple and compact monoplane
structure had been achieved with main landing gear
retracting into a broad mainplane section. The pilot's cockpit
and rear turret were faired into a streamlined upper fuselage section. Fuel was carried in the wing centre section along with a large ventral radiator
that completed the resemblance to the Hawker fighter. With a 1,030 hp (768 kW) Rolls-Royce Merlin
I, the newly named "Defiant" prototype first flew on 11 August 1937, nearly a year ahead of the Hotspur. A second prototype, K8620 equipped with a turret was modified with telescopic radio masts, revision to the canopy and changes to the undercarriage fairing plates.
Completing its acceptance tests with the turret installed, the Defiant reached a top speed of 302 mph (486 km/h) and subsequently was declared the victor of the turret fighter competition. Apart from detail changes, the production Defiant Mk I looked similar to the two Defiant prototypes. As Boulton Paul were busy producing the Blackburn Roc
naval turret fighter, the Defiant's service entry was delayed to such an extent that only three aircraft had reached the RAF by the start of the war. The Mk I was powered by the Rolls Royce Merlin III (1,030 hp/768 kW or 1,160 hp/865 kW) with a total of 713 aircraft built.
(FAA); it had a deeper fuselage and leading edge slats for lower landing speeds required of carrier aircraft. The engine would be either a Bristol Hercules radial or the Merlin. Despite a higher estimated top speed, the Blackburn Roc was selected. With Blackburn already busy producing other projects, the detail design and production of the Roc was given to Boulton Paul. The only FAA use of the Defiant was as the target tug version.
and did not require a new single-seat fighter. With a calculated top speed of about 360 mph (579 km/h) at 21,700 ft, the P.94 was almost as fast as a contemporary Spitfire although less manoeuvrable.
In October 1939 No. 264 (Madras Presidency) Squadron
was reformed at RAF Sutton Bridge
to operate the Defiant. Initial training and development of tactics began with other aircraft as it only received their first Defiants in early December at Martlesham Heath. They began night fighter training in February 1940. The squadron tested their tactics against British medium bombers – Hampdens and Blenheims
– and 264's CO flew against Robert Stanford Tuck
in a Spitfire showing the Defiant could defend itself by circling and keeping its speed up. By March, 264 Squadron had two flights operational with Defiants and No. 141 Squadron received its first Defiant. When the Defiant was first introduced to the public, the RAF put out a disinformation campaign, stating that the Defiant had 21 guns—i.e. four in the turret, fourteen in the wings and three cannons in the nose.
The first operational sortie came on 12 May 1940. Defiants flew with six Spitfires of 66 Sqn, and a Ju 88 was shot down over Holland. The following day, in a patrol that was a repetition of the first, Defiants claimed four Ju 87s, but were subsequently attacked by Bf 109Es. The escorting Spitfires were unable to prevent five of the six Defiants being shot down by a frontal attack.
During the evacuation of the British Expeditionary Force
from Dunkirk, the Squadron was forward based at RAF Manston
one of the 16 Squadrons that No. 11 Group had available to cover the evacuation. On the 27th 264 Sqn claimed 3 He 111 and 2 damaged. On the 28th, shortly after take-off ten Defiants were attacked by about 30 Bf 109s – forming a circle, six German fighters were claimed for the loss of three Defiants.
The Defiant was initially successful against enemy aircraft. Its best day was 29 May 1940, when No. 264 Sqn claimed 37 kills in two sorties: 19 Junkers Ju 87
Stuka dive bombers mostly picked off as they came out of their dives, nine Messerschmitt Bf 110
twin-engined heavy fighters, eight Bf 109s and a Ju-88. One Defiant gunner was lost after he bailed out though the aircraft made base to be repaired.
Initially, Luftwaffe fighters suffered losses when "bouncing" flights of Defiants from the rear, apparently mistaking them for Hurricanes. The German pilots were unaware of the Defiant's rear-firing armament and encountered concentrated defensive fire. With a change in Luftwaffe tactics, opposing fighters were able to out-manoeuvre the Defiant and attack it from below or dead ahead, where the turret offered no defence. Defiant losses quickly mounted, particularly among the gunners who were often unable to leave stricken aircraft. The additional weight of the turret and the second crewman plus the aerodynamic drag, gave the Defiant lower performance than conventional fighter aircraft.
According to the book The Turret Fighters by aviation historian
Alec Brew, 264 Sqn. developed a counter against single-seat aircraft such as the Bf 109. By flying in an ever-descending Lufberry circle, Defiant crews sacrificed the advantage of height but eliminated the possibility of attack from underneath, while giving 360° of defensive fire. This tactic was used successfully by 264 Sqn. but when the Defiants of 141 Sqn.
were committed to combat a few months later during the Battle of Britain
, it chose to ignore their advice with devastating consequences. On 19 July 1940, seven out of nine Defiants of 141 Sqn. sent to cover a convoy off Folkestone were shot down by Bf 109s of JG 51 and the remaining two only survived, one badly damaged, due to the intervention of Hurricanes of 111 Sqn.
The Hurricanes reported that the Defiants had shot down four Bf 109s. Although 264 Sqn. claimed 48 kills in eight days over Dunkirk, the cost was high with 14 Defiants lost. The actual German losses were no more than 12 to 15 enemy aircraft; the turret's wide angle of fire meant that several Defiants could engage the same target at one time leading to multiple claims.
264 Squadron lost three aircraft on 26 August (two to ace Hpt. Gunther Lutzow of JG 3) and five on 28 August (to JG 26), with the deaths of nine crew members. With these losses, the Defiant - which had been intended from the start as a day and night fighter - was transferred to night fighting and there the Defiant achieved some success.
Defiant night fighters typically attacked enemy bombers from below, in a similar manoeuvre to the later successful German Schräge Musik
methods. Defiants attacked more often from slightly ahead or to one side, rather than from directly under the tail. During the winter Blitz
on London
of 1940–41, the Defiant equipped four squadrons, shooting down more enemy aircraft than any other type. The turret-fighter concept was not immediately discarded and the fitting of Defiant-type turrets to Beaufighter
and Mosquito
night fighters was tried to enable these aircraft to duplicate these methods but the effect on performance proved drastic and the idea was abandoned. The Defiant Mk II model was fitted with the AI Mk IV airborne interception radar
and a Merlin XX engine. A total of 207 Mk II Defiants were built.
After trials in 1940 with the School of Army Co-operation to assess its capabilities in that role, the Defiant was tested as a high-speed gunnery trainer with the Air Ministry agreeing to continue production. The Defiant was removed from combat duties in 1942 and used for training, target towing, Electronic countermeasures
and air-sea rescue
.
Two types of Electronic Countermeasures equipment were carried by the Defiant, both countering the German Freya
early warning radar. The first system to be deployed was "Moonshine" which re-transmitted the radar's signals to simulate large formations of aircraft. As each "Moonshine" transmitter only covered part of the Freya's frequency, a formation of eight Defiants were needed, giving the appearance of over 100 aircraft. As the system required formation flying, it could only be used in daylight, where it could draw German fighters onto British fighters leaving another area relatively free for a British bombing raid. A "Special Duties Flight" was set up in May 1942 to use the new countermeasures equipment, with "Moonshine" being used for its first live test on 6 August 1942. Subsequently it was used operationally as part of "Circuses" against coastal targets and on 19 August in support of the Dieppe Raid. The Flight became No. 515 Squadron RAF
on 1 October 1942, operations with "Moonshine" continuing until November 1942.
515 Squadron continued operations with the second countermeasures system, "Mandrel", a noise jammer which overwhelmed the signals from Freya. Individual Defiants were sent to orbit positions 50 miles (80 km) off the enemy coast. By using nine aircraft a 200-mile (320-km) gap could be made in the Germans' radar coverage. 515 Squadron flew its first mission using Mandrel on the night of 5/6 December 1942, continuing to use its Defiants for jamming operations until the spring of 1943, when it began to receive twin-engined Bristol Beaufighter
s which had longer range and could carry more electronic equipment. The Defiant flew its last jamming mission on 17 July 1943, with one aircraft being lost out of four sent out that night.
In air-sea rescue the Defiant was equipped with a pair of under-wing pods that contained dinghies. A further 140 Defiant Mk III aircraft were built; this model lacked the dorsal turret and was used as a target tug
. Many of the surviving Mk I and Mk II Defiants also had their turrets removed.
In this final target towing variant, the Defiant ended up with a number of overseas assignments with both the RAF and Fleet Air Arm in the Middle East, Africa and India. Further deployments occurred to Canada
, where the Defiant was used as both a target tug and trainer with the British Commonwealth Air Training Plan
.
Defiants were also used for "special" work including tactical evaluations with the RAF Gunnery Research Unit and the Air Fighting Development Unit
(AFDU) at Farnborough
. Two Defiants were issued for ejection seat development work; to R Malcolm Ltd and Martin-Baker
. On 11 May 1945, Martin-Baker used Defiant, DR944, to test their first ejection seat with dummy launches.
The last operational use of Defiants was in India
, where they were used as target tugs.
Defiant NF Mk I
Defiant NF Mk IA
Defiant ASR Mk I
Defiant TT Mk I
Defiant Mk II
Defiant TT Mk III
at the Royal Air Force Museum in Hendon, London. It was one of four Defiants delivered to No. 307 Polish Night Fighter Squadron
at RAF Kirton in Lindsey
, Lincolnshire
, England on 17 September 1940. It was passed to No. 153 Squadron at the end of October 41 and 285 Sqn in 1942. In 1954 it was identified for storage as a historical aircraft and passed to the RAF Museum in 1971.
The aircraft was moved on 20 May 2009 to Rochester airport where it will be restored by the Medway Aircraft Preservation Society (MAPS).
Major parts of at least two other Defiants survive; N1766 and N3378, both Mk Is.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
interceptor aircraft
Interceptor aircraft
An interceptor aircraft is a type of fighter aircraft designed specifically to prevent missions of enemy aircraft, particularly bombers and reconnaissance aircraft. Interceptors generally rely on high speed and powerful armament in order to complete their mission as quickly as possible and set up...
that served with the Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
(RAF) early in the Second World War. The Defiant was designed and built by Boulton Paul Aircraft
Boulton Paul Aircraft
Boulton Paul Aircraft Ltd was a British aircraft manufacturer that was created in 1934, although its origins lay in 1914, and lasted until 1961...
as a "turret fighter", without any forward-firing guns. It was a contemporary of the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
's Blackburn Roc
Blackburn Roc
|-See also:-References:NotesBibliography* Brew, Alec. The Turret Fighters: Defiant and Roc. Ramsbury, Marlborough, Wiltshire, UK: Crowood Press, 2002. ISBN 1-86126-497-6....
. The concept of a turret fighter related directly to the successful First World War-era Bristol F.2 Fighter
Bristol F.2 Fighter
The Bristol F.2 Fighter was a British two-seat biplane fighter and reconnaissance aircraft of the First World War flown by the Royal Flying Corps. It is often simply called the Bristol Fighter or popularly the "Brisfit" or "Biff". Despite being a two-seater, the F.2B proved to be an agile aircraft...
.
In practice, the Defiant was found to be vulnerable to the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
s more agile, single-seat Messerschmitt Bf 109
Messerschmitt Bf 109
The Messerschmitt Bf 109, often called Me 109, was a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid 1930s...
fighters. It became used as a night fighter
Night fighter
A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...
until it was supplanted in that role by the Bristol Beaufighter
Bristol Beaufighter
The Bristol Type 156 Beaufighter, often referred to as simply the Beau, was a British long-range heavy fighter modification of the Bristol Aeroplane Company's earlier Beaufort torpedo bomber design...
and de Havilland Mosquito
De Havilland Mosquito
The de Havilland DH.98 Mosquito was a British multi-role combat aircraft that served during the Second World War and the postwar era. It was known affectionately as the "Mossie" to its crews and was also nicknamed "The Wooden Wonder"...
. The Defiant found use in gunnery training, target towing, electronic countermeasures
Electronic countermeasures
An electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...
(ECM) and air-sea rescue
Air-sea rescue
Air-sea rescue is the coordinated search and rescue of the survivors of emergency water landings as well as people who have survived the loss of their sea-going vessel. ASR can involve a wide variety of resources including seaplanes, helicopters, submarines, rescue boats and ships...
. Among RAF pilots, it had the nickname "Daffy", probably a diminutive of the word "Defiant".
Evolution
Biplane
A biplane is a fixed-wing aircraft with two superimposed main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...
fighters in service. The RAF believed that its turret-armed bombers, such as the Vickers Wellington
Vickers Wellington
The Vickers Wellington was a British twin-engine, long range medium bomber designed in the mid-1930s at Brooklands in Weybridge, Surrey, by Vickers-Armstrongs' Chief Designer, R. K. Pierson. It was widely used as a night bomber in the early years of the Second World War, before being displaced as a...
, would be able to penetrate enemy airspace and defend themselves without fighter escort and also that the German Luftwaffe would be able to do the same.
In theory, turret-armed fighters would approach an enemy bomber from below or from the side and coordinate their fire. The separation of the tasks of flying the aircraft and firing the guns would allow the pilot to concentrate on putting the fighter into the best position while the gunner could engage the enemy. Previously the Hawker Demon had tested the concept with 59 of the biplane fighters (manufactured by Boulton Paul under a sub-contract) equipped with a powered rear turret while the remainder of the series already manufactured were converted.
Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...
Specification F.9/35 required a two-seater day and night "turret fighter" capable of 290 mph at 15,000 ft. It followed the earlier F.5/33 which was for a pusher design with a front turret. F.5/33 had been abandoned as it offered little over existing fighters and the Armstrong Whitworth AW.34 design which had been ordered was not completed.
P.82
Boulton Paul, who had considerable experience with turrets from their earlier OverstrandBoulton Paul Overstrand
-See also:-References:NotesBibliography* Brew, Alec. Boulton Paul Aircraft since 1915. London: Putnam, 1993. ISBN 0-85177-860-7.* Halley, James J. Royal Air Force Aircraft: K1000 to K9999. Tonbridge, Kent, UK: Air-Britain Ltd., 1976. ISBN 0-851330-048-0.* Lewis, Peter. The British Bomber since...
bomber, submitted their P.82 design. Of the seven designs tendered, the P.82 was ranked second after Hawkers but ahead of Armstrong Whitworths twin-engined design. The Air Ministry wanted several designs investigated and two prototypes of each. The Treasury agreed to seven prototypes (2 Hawker, 2 Boulton Paul, 2 Fairey and 1 Armstrong Whitworth). In the event only prototypes of the P.82 and Hawker were built. Production orders were prepared for the Hawker but the Boulton Paul turret had the Air Ministry's attention. Delays by Hawker who were more focussed on the Hurricane led to the P.82 receiving a production order in 1937 and the Hotspur order was cancelled in 1938.
The P.82 was a monocque design constructed by bolting the sections together. This was the same as BP had used on other aircraft. The design had room for small bombs in recesses in the outer wing. Some of the development work from their B.1/35 tender carried over into the P.82
The central feature of the P.82 was the four-gun turret based on a design by French aviation company SAMM which had been licensed by Boulton Paul for use in the earlier Boulton Paul Sidestrand
Boulton Paul Sidestrand
|-See also:-References:NotesBibliography* Brew, Alec. Boulton Paul Aircraft since 1915. London: Putnam, 1993. ISBN 0-85177-860-7.* Jarrett, Philip. "By Day and By Night: Sidestrand and Overstrand, Part 1." Aeroplane Monthly, Vol. 22, No. 11, Issue 259, November 1994, pp. 18—23. London: IPC. ISSN...
bomber but eventually installed in the "follow-up" design, the Boulton Paul Overstrand
Boulton Paul Overstrand
-See also:-References:NotesBibliography* Brew, Alec. Boulton Paul Aircraft since 1915. London: Putnam, 1993. ISBN 0-85177-860-7.* Halley, James J. Royal Air Force Aircraft: K1000 to K9999. Tonbridge, Kent, UK: Air-Britain Ltd., 1976. ISBN 0-851330-048-0.* Lewis, Peter. The British Bomber since...
and Blackburn Roc
Blackburn Roc
|-See also:-References:NotesBibliography* Brew, Alec. The Turret Fighters: Defiant and Roc. Ramsbury, Marlborough, Wiltshire, UK: Crowood Press, 2002. ISBN 1-86126-497-6....
naval fighter. The turret, 'Type A' was an electro-hydraulically powered "drop-in" unit with a crank-operated mechanical backup. The Defiant was armed with a powered dorsal turret, equipped with four 0.303 in (7.7 mm)
.303 British
.303 British, or 7.7x56mmR, is a .311 inch calibre rifle and machine gun cartridge first developed in Britain as a blackpowder round put into service in December 1888 for the Lee-Metford rifle, later adapted to use smokeless powders...
Browning machine gun
M1919 Browning machine gun
The M1919 Browning is a .30 caliber medium machine gun that was widely used during the 20th century. It was used as a light infantry, coaxial, mounted, aircraft, and anti-aircraft machine gun by the U.S. and many other countries, especially during World War II, the Korean War, and the Vietnam War...
s. The fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
was fitted with aerodynamic fairings that helped mitigate the drag of the turret; they were pneumatically powered and could be lowered into the fuselage so that the turret could rotate freely. The Brownings were electrically fired and insulated cut-off points in the turret ring prevented the guns firing when they were pointing at the propeller disc or tailplane. The gunner could rotate the turret directly forward and transfer firing control of the guns to the pilot, with the guns firing along each side of the cockpit canopy. However, in practice this was rarely done as the turret's minimum forward elevation was 19° and the pilot did not have a gunsight.
The gunner's hatch was in the rear of the turret, which had to be rotated to a side to enable entry and exit. There was not enough room in the turret for the gunner to wear a seat-type or back pack parachute so gunners were provided with a special all-in-one garment nicknamed the "rhino suit". To quote Frederick "Gus" Platts, air gunner in 230, 282 and 208 squadrons, "The Rhino suit we had to wear on Defiants was a bear but I couldn't come up with an alternative, even though it killed dozens of us. I forget the details of it but we could not have sat on our chute or even keep it nearby as in other turrets, so you wore – all in one – an inner layer that fitted a little like a wetsuit of today. The chute fitted around this, and then the dinghy and the outer clothing. There was inner webbing and pockets that literally fell apart (I presume) when one bailed out".
The first P.82 prototype (K8310) was rolled out in 1937 without its turret, looking like the Hawker Hurricane
Hawker Hurricane
The Hawker Hurricane is a British single-seat fighter aircraft that was designed and predominantly built by Hawker Aircraft Ltd for the Royal Air Force...
, although it was at least 1,500 lb (680 kg) heavier. A clean, simple and compact monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...
structure had been achieved with main landing gear
Conventional landing gear
thumb|The [[Piper PA-18|Piper Super Cub]] is a popular taildragger aircraft.thumb|right|A [[Cessna 150]] converted to taildragger configuration by installation of an after-market modification kit....
retracting into a broad mainplane section. The pilot's cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
and rear turret were faired into a streamlined upper fuselage section. Fuel was carried in the wing centre section along with a large ventral radiator
Radiator (engine cooling)
Radiators are used for cooling internal combustion engines, mainly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plant or any similar use of such an engine....
that completed the resemblance to the Hawker fighter. With a 1,030 hp (768 kW) Rolls-Royce Merlin
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
I, the newly named "Defiant" prototype first flew on 11 August 1937, nearly a year ahead of the Hotspur. A second prototype, K8620 equipped with a turret was modified with telescopic radio masts, revision to the canopy and changes to the undercarriage fairing plates.
Completing its acceptance tests with the turret installed, the Defiant reached a top speed of 302 mph (486 km/h) and subsequently was declared the victor of the turret fighter competition. Apart from detail changes, the production Defiant Mk I looked similar to the two Defiant prototypes. As Boulton Paul were busy producing the Blackburn Roc
Blackburn Roc
|-See also:-References:NotesBibliography* Brew, Alec. The Turret Fighters: Defiant and Roc. Ramsbury, Marlborough, Wiltshire, UK: Crowood Press, 2002. ISBN 1-86126-497-6....
naval turret fighter, the Defiant's service entry was delayed to such an extent that only three aircraft had reached the RAF by the start of the war. The Mk I was powered by the Rolls Royce Merlin III (1,030 hp/768 kW or 1,160 hp/865 kW) with a total of 713 aircraft built.
P.85
The P.85 was Boulton Paul's tender to Specification O.30/35 for the naval turret fighter. A version of the Defiant for Fleet Air ArmFleet Air Arm
The Fleet Air Arm is the branch of the British Royal Navy responsible for the operation of naval aircraft. The Fleet Air Arm currently operates the AgustaWestland Merlin, Westland Sea King and Westland Lynx helicopters...
(FAA); it had a deeper fuselage and leading edge slats for lower landing speeds required of carrier aircraft. The engine would be either a Bristol Hercules radial or the Merlin. Despite a higher estimated top speed, the Blackburn Roc was selected. With Blackburn already busy producing other projects, the detail design and production of the Roc was given to Boulton Paul. The only FAA use of the Defiant was as the target tug version.
P.94
The first Defiant prototype had not been initially fitted with a turret and therefore had an impressive top speed. In 1940, Boulton Paul removed the turret from the prototype as a demonstrator for a fixed gun fighter based on Defiant components. The armament offered was either 12 .303 in (7.7 mm) Browning machine guns (six per wing) or 4 20mm Hispano replacing 8 of the Brownings. The guns could be depressed for ground attack. By that time, the RAF had sufficient quantities of Hawker Hurricanes and Supermarine SpitfireSupermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...
and did not require a new single-seat fighter. With a calculated top speed of about 360 mph (579 km/h) at 21,700 ft, the P.94 was almost as fast as a contemporary Spitfire although less manoeuvrable.
Operational history
No. 264 Squadron RAF
No. 264 Squadron RAF also known as No 264 Squadron was a squadron of the Royal Air Force formed from two former Royal Naval Air Service flights, No. 439 and No. 440, on 27 September 1918 at Souda Bay, Crete to perform anti-submarine patrols. It operated the Short 184 floatplanes on patrols in the...
was reformed at RAF Sutton Bridge
RAF Sutton Bridge
RAF Sutton Bridge is a former RAF airfield found next to the village of Sutton Bridge in the south-east of Lincolnshire. The airfield was to the south of the current A17, and east of the River Nene, next to Walpole in Norfolk.-History:...
to operate the Defiant. Initial training and development of tactics began with other aircraft as it only received their first Defiants in early December at Martlesham Heath. They began night fighter training in February 1940. The squadron tested their tactics against British medium bombers – Hampdens and Blenheims
Bristol Blenheim
The Bristol Blenheim was a British light bomber aircraft designed and built by the Bristol Aeroplane Company that was used extensively in the early days of the Second World War. It was adapted as an interim long-range and night fighter, pending the availability of the Beaufighter...
– and 264's CO flew against Robert Stanford Tuck
Robert Stanford Tuck
Wing Commander Roland Robert Stanford Tuck DSO, DFC & Two Bars, AFC was a British fighter pilot and test pilot.Tuck joined the RAF in 1935. Tuck first engaged in combat during the Battle of France, over Dunkirk, claiming his first victories...
in a Spitfire showing the Defiant could defend itself by circling and keeping its speed up. By March, 264 Squadron had two flights operational with Defiants and No. 141 Squadron received its first Defiant. When the Defiant was first introduced to the public, the RAF put out a disinformation campaign, stating that the Defiant had 21 guns—i.e. four in the turret, fourteen in the wings and three cannons in the nose.
The first operational sortie came on 12 May 1940. Defiants flew with six Spitfires of 66 Sqn, and a Ju 88 was shot down over Holland. The following day, in a patrol that was a repetition of the first, Defiants claimed four Ju 87s, but were subsequently attacked by Bf 109Es. The escorting Spitfires were unable to prevent five of the six Defiants being shot down by a frontal attack.
During the evacuation of the British Expeditionary Force
Operation Dynamo
The Dunkirk evacuation, commonly known as the Miracle of Dunkirk, code-named Operation Dynamo by the British, was the evacuation of Allied soldiers from the beaches and harbour of Dunkirk, France, between 26 May and the early hours of 3 June 1940, because the British, French and Belgian troops were...
from Dunkirk, the Squadron was forward based at RAF Manston
RAF Manston
RAF Manston was an RAF station in the north-east of Kent, at on the Isle of Thanet from 1916 until 1996. The site is now split between a commercial airport Kent International Airport and a continuing military use by the Defence Fire Training and Development Centre , following on from a long...
one of the 16 Squadrons that No. 11 Group had available to cover the evacuation. On the 27th 264 Sqn claimed 3 He 111 and 2 damaged. On the 28th, shortly after take-off ten Defiants were attacked by about 30 Bf 109s – forming a circle, six German fighters were claimed for the loss of three Defiants.
The Defiant was initially successful against enemy aircraft. Its best day was 29 May 1940, when No. 264 Sqn claimed 37 kills in two sorties: 19 Junkers Ju 87
Junkers Ju 87
The Junkers Ju 87 or Stuka was a two-man German ground-attack aircraft...
Stuka dive bombers mostly picked off as they came out of their dives, nine Messerschmitt Bf 110
Messerschmitt Bf 110
The Messerschmitt Bf 110, often called Me 110, was a twin-engine heavy fighter in the service of the Luftwaffe during World War II. Hermann Göring was a proponent of the Bf 110, and nicknamed it his Eisenseiten...
twin-engined heavy fighters, eight Bf 109s and a Ju-88. One Defiant gunner was lost after he bailed out though the aircraft made base to be repaired.
Initially, Luftwaffe fighters suffered losses when "bouncing" flights of Defiants from the rear, apparently mistaking them for Hurricanes. The German pilots were unaware of the Defiant's rear-firing armament and encountered concentrated defensive fire. With a change in Luftwaffe tactics, opposing fighters were able to out-manoeuvre the Defiant and attack it from below or dead ahead, where the turret offered no defence. Defiant losses quickly mounted, particularly among the gunners who were often unable to leave stricken aircraft. The additional weight of the turret and the second crewman plus the aerodynamic drag, gave the Defiant lower performance than conventional fighter aircraft.
According to the book The Turret Fighters by aviation historian
Historian
A historian is a person who studies and writes about the past and is regarded as an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the study of all history in time. If the individual is...
Alec Brew, 264 Sqn. developed a counter against single-seat aircraft such as the Bf 109. By flying in an ever-descending Lufberry circle, Defiant crews sacrificed the advantage of height but eliminated the possibility of attack from underneath, while giving 360° of defensive fire. This tactic was used successfully by 264 Sqn. but when the Defiants of 141 Sqn.
No. 141 Squadron RAF
No. 141 Squadron of the Royal Air Force was formed on 1 January 1918 at Rochford, for home defence in the London Area. The Squadron moved to RAF Biggin Hill in February and giving up its mixed collection of types in favour of Bristol F.2 Fighters during March...
were committed to combat a few months later during the Battle of Britain
Battle of Britain
The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...
, it chose to ignore their advice with devastating consequences. On 19 July 1940, seven out of nine Defiants of 141 Sqn. sent to cover a convoy off Folkestone were shot down by Bf 109s of JG 51 and the remaining two only survived, one badly damaged, due to the intervention of Hurricanes of 111 Sqn.
No. 111 Squadron RAF
No. 111 Squadron of the Royal Air Force operated the Panavia Tornado F3 from RAF Leuchars, Scotland until March 2011, when the squadron was disbanded, ending the Tornado F3's RAF service.-In World War I:...
The Hurricanes reported that the Defiants had shot down four Bf 109s. Although 264 Sqn. claimed 48 kills in eight days over Dunkirk, the cost was high with 14 Defiants lost. The actual German losses were no more than 12 to 15 enemy aircraft; the turret's wide angle of fire meant that several Defiants could engage the same target at one time leading to multiple claims.
264 Squadron lost three aircraft on 26 August (two to ace Hpt. Gunther Lutzow of JG 3) and five on 28 August (to JG 26), with the deaths of nine crew members. With these losses, the Defiant - which had been intended from the start as a day and night fighter - was transferred to night fighting and there the Defiant achieved some success.
Defiant night fighters typically attacked enemy bombers from below, in a similar manoeuvre to the later successful German Schräge Musik
Schräge Musik
Schräge Musik, derived from the German colloquialism for "Jazz Music" was the name given to installations of upward-firing autocannon mounted in night fighters by the Luftwaffe and Imperial Japanese Navy Air Service during World War II, with the first victories for each occurring in May 1943...
methods. Defiants attacked more often from slightly ahead or to one side, rather than from directly under the tail. During the winter Blitz
The Blitz
The Blitz was the sustained strategic bombing of Britain by Nazi Germany between 7 September 1940 and 10 May 1941, during the Second World War. The city of London was bombed by the Luftwaffe for 76 consecutive nights and many towns and cities across the country followed...
on London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
of 1940–41, the Defiant equipped four squadrons, shooting down more enemy aircraft than any other type. The turret-fighter concept was not immediately discarded and the fitting of Defiant-type turrets to Beaufighter
Bristol Beaufighter
The Bristol Type 156 Beaufighter, often referred to as simply the Beau, was a British long-range heavy fighter modification of the Bristol Aeroplane Company's earlier Beaufort torpedo bomber design...
and Mosquito
De Havilland Mosquito
The de Havilland DH.98 Mosquito was a British multi-role combat aircraft that served during the Second World War and the postwar era. It was known affectionately as the "Mossie" to its crews and was also nicknamed "The Wooden Wonder"...
night fighters was tried to enable these aircraft to duplicate these methods but the effect on performance proved drastic and the idea was abandoned. The Defiant Mk II model was fitted with the AI Mk IV airborne interception radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
and a Merlin XX engine. A total of 207 Mk II Defiants were built.
After trials in 1940 with the School of Army Co-operation to assess its capabilities in that role, the Defiant was tested as a high-speed gunnery trainer with the Air Ministry agreeing to continue production. The Defiant was removed from combat duties in 1942 and used for training, target towing, Electronic countermeasures
Electronic countermeasures
An electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...
and air-sea rescue
Air-sea rescue
Air-sea rescue is the coordinated search and rescue of the survivors of emergency water landings as well as people who have survived the loss of their sea-going vessel. ASR can involve a wide variety of resources including seaplanes, helicopters, submarines, rescue boats and ships...
.
Two types of Electronic Countermeasures equipment were carried by the Defiant, both countering the German Freya
Freya radar
Freya was an early warning radar deployed by Germany during World War II, named after the Norse Goddess Freyja. During the war over a thousand stations were built. A naval version operating on a slightly different wavelength was also developed as Seetakt...
early warning radar. The first system to be deployed was "Moonshine" which re-transmitted the radar's signals to simulate large formations of aircraft. As each "Moonshine" transmitter only covered part of the Freya's frequency, a formation of eight Defiants were needed, giving the appearance of over 100 aircraft. As the system required formation flying, it could only be used in daylight, where it could draw German fighters onto British fighters leaving another area relatively free for a British bombing raid. A "Special Duties Flight" was set up in May 1942 to use the new countermeasures equipment, with "Moonshine" being used for its first live test on 6 August 1942. Subsequently it was used operationally as part of "Circuses" against coastal targets and on 19 August in support of the Dieppe Raid. The Flight became No. 515 Squadron RAF
No. 515 Squadron RAF
No. 515 Squadron RAF was a squadron of the Royal Air Force formed during the Second World War. It stood at the brink of Electronic countermeasures warfare, jamming enemy radar installations from October 1942. This was first done as only such squadron in the RAF, but later in the war together with...
on 1 October 1942, operations with "Moonshine" continuing until November 1942.
515 Squadron continued operations with the second countermeasures system, "Mandrel", a noise jammer which overwhelmed the signals from Freya. Individual Defiants were sent to orbit positions 50 miles (80 km) off the enemy coast. By using nine aircraft a 200-mile (320-km) gap could be made in the Germans' radar coverage. 515 Squadron flew its first mission using Mandrel on the night of 5/6 December 1942, continuing to use its Defiants for jamming operations until the spring of 1943, when it began to receive twin-engined Bristol Beaufighter
Bristol Beaufighter
The Bristol Type 156 Beaufighter, often referred to as simply the Beau, was a British long-range heavy fighter modification of the Bristol Aeroplane Company's earlier Beaufort torpedo bomber design...
s which had longer range and could carry more electronic equipment. The Defiant flew its last jamming mission on 17 July 1943, with one aircraft being lost out of four sent out that night.
In air-sea rescue the Defiant was equipped with a pair of under-wing pods that contained dinghies. A further 140 Defiant Mk III aircraft were built; this model lacked the dorsal turret and was used as a target tug
Target tug
A target tug is an aircraft which tows an unmanned drone, a fabric drogue or other kind of target, for the purposes of gun or missile target practice. Target tugs are often conversions of transport and utility aircraft, as well as obsolescent combat types...
. Many of the surviving Mk I and Mk II Defiants also had their turrets removed.
In this final target towing variant, the Defiant ended up with a number of overseas assignments with both the RAF and Fleet Air Arm in the Middle East, Africa and India. Further deployments occurred to Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, where the Defiant was used as both a target tug and trainer with the British Commonwealth Air Training Plan
British Commonwealth Air Training Plan
The British Commonwealth Air Training Plan , known in some countries as the Empire Air Training Scheme , was a massive, joint military aircrew training program created by the United Kingdom, Canada, Australia and New Zealand, during the Second World War...
.
Defiants were also used for "special" work including tactical evaluations with the RAF Gunnery Research Unit and the Air Fighting Development Unit
Air Fighting Development Unit
The Air Fighting Development Unit was an air technical intelligence part of the Royal Air Force which developed operational tactics and tested captured enemy aircraft. It was based at Royal Air Force Stations at Northolt, Duxford and Wittering....
(AFDU) at Farnborough
Farnborough Airfield
Farnborough Airport or TAG London Farnborough Airport is an airport situated in Farnborough, Rushmoor, Hampshire, England...
. Two Defiants were issued for ejection seat development work; to R Malcolm Ltd and Martin-Baker
Martin-Baker
Martin-Baker Aircraft Co. Ltd. is a manufacturer of ejection seats and safety related equipment for aviation. The company origins were as an aircraft manufacturer before becoming a pioneer in the field of ejection seats...
. On 11 May 1945, Martin-Baker used Defiant, DR944, to test their first ejection seat with dummy launches.
The last operational use of Defiants was in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, where they were used as target tugs.
Variants
Defiant Mk I- Two-seat turret fighter for the RAF, powered by a 1,030 hp (768 kW) Rolls-Royce Merlin III piston engine; 723 built.
Defiant NF Mk I
- Defiant Mk I converted into night fighters
Defiant NF Mk IA
- NF Mk I with Airborne Interception radar.
Defiant ASR Mk I
- Mk I carrying air-dropped dingies for air-sea rescueAir-sea rescueAir-sea rescue is the coordinated search and rescue of the survivors of emergency water landings as well as people who have survived the loss of their sea-going vessel. ASR can involve a wide variety of resources including seaplanes, helicopters, submarines, rescue boats and ships...
.
Defiant TT Mk I
- Defiant Mk IIs converted to target tugs; 150 conversions.
Defiant Mk II
- Two-seat night fighter for the RAF, powered by a 1,280 hp (954 kW) Rolls-Royce Merlin XX piston engine, and fitted with the AI Mk IV airborne interception radar; 210 built.
Defiant TT Mk III
- Dedicated turret-less target tug; 140 built from new.
Survivors
The single surviving complete example of the type is a Defiant I, N1671, on display as a night fighterNight fighter
A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...
at the Royal Air Force Museum in Hendon, London. It was one of four Defiants delivered to No. 307 Polish Night Fighter Squadron
No. 307 Polish Night Fighter Squadron
No. 307 Polish Night Fighter Squadron was a Polish night fighter squadron formed in Great Britain on 24 August 1940 as a result of an agreement between the Polish Government in Exile and the United Kingdom...
at RAF Kirton in Lindsey
RAF Kirton in Lindsey
RAF Kirton in Lindsey is a Royal Air Force airfield in Lincolnshire. The field is located 15 miles north of Lincoln.It hosts No.1 Air Control Centre , the RAF’s only deployable ground-based early warning and air control radar unit, parented by RAF Scampton.-First World War:The Royal Flying Corps...
, Lincolnshire
Lincolnshire
Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...
, England on 17 September 1940. It was passed to No. 153 Squadron at the end of October 41 and 285 Sqn in 1942. In 1954 it was identified for storage as a historical aircraft and passed to the RAF Museum in 1971.
The aircraft was moved on 20 May 2009 to Rochester airport where it will be restored by the Medway Aircraft Preservation Society (MAPS).
Major parts of at least two other Defiants survive; N1766 and N3378, both Mk Is.
Specifications (Mk I)
See also
External links
- Death of the Defiant: A closer look at the Defiant, its faults and its achievements
- Fleet Air Arm Archive
- Aeroflight.co.uk
- The Boulton Paul Association
- Boulton Paul Defiant profile, technical details and photos
- "Defiant – nightfighter role", Youtube video
- "Boulton Paul Defiant." Flight, 12 February 1942, pp. 132–135.