Sons of Damien



Full Listing


Quick Links;


Other Aircraft:





Boulton Paul Defiant

Boulton Paul Defiant: Deriving from an Air Ministry Specification F.9/35, calling for a two-seat fighter with a power operated gun turret, both Boulton Paul and Hawker made submissions. The Hawker Hotspur prototype was not, however, to compete against the two which were ordered from Boulton Paul, primarily because the Hawker factories had no productive capacity available, and consequently the Hotspur prototype was abandoned.

Named Defiant, the first of Boulton Paulís prototypes (K8310) made its initial flight on 11th August 1937. It was a low-wing cantilever monoplane of all-metal construction, provided with retractable tail wheel type landing gear, and powered by a 1,030-hp (768-kW) Rolls-Royce Merlin I inline engine: the second prototype (K8620) had a Merlin II engine. Both, of course, had a large and heavy four-gun turret mounted within the fuselage aft of the pilotís cockpit. Itís weight, and the high degree of drag imposed by the protruding section of the turret, no matter how cleverly faired in, was to impose limits on speed and manoeuvrability.

Boulton Paul Defiant Prototype K8310

The first production Defiant F.MkI day fighter was flown on 30th July 1939, and deliveries to No.234 squadron began in December of that year. It was this squadron which first deployed the type operationally, on 12th May 1940 over the beaches of Dunkirk, achieving complete tactical surprise. Fighters making conventional attacks on the tail of the Defiants were met with an unprecedented burst of fire from the four machine guns: on one day they claimed 38 enemy aircraft destroyed, and a total of 65 by the end of May. It was, however, only brief air superiority, for it did not take long for Luftwaffe fighter pilots to discover that they could attack head on, or against the belly of the Defiant, with complete immunity. The days of these fighters were numbered, and they were withdrawn from daylight operations in August 1940.

It was instead decided to use the Defiant in a night fighter role, and the comparatively new and highly secret AI radar was installed in many of the MkI aircraft, comprising either AI Mk IV or Mk VI, aircraft so fitted being designated NF.Mk IA. With this equipment they were to prove a valuable addition to Britainís night defences in the winter of 1940-41, and during this period they were to record more Ďkillsí per interception than any other contemporary night fighter.

In an attempt to improve performance of the Defiant, two MkIís served for conversion as prototypes of the new MkII version, the first being N1550. Apart from the installation of a more powerful Merlin XX engine, fuel capacity was increased, a rudder of greater area was provided, and there were modifications to the engine cooling and fuel systems. First flown on 20th June 1040, there were 210 examples of the Defiant MkII built, of which many were later converted as TT.MkI target tugs. A specialised Target-tug version of the Defiant was first ordered in July 1941, designated the T.T. Mk I. The new version was based on the Mk II airframe, with the Merlin XX engine, but with space formerly occupied by the turret now taken up with an observerís station with a small canopy. A fairing under the rear fuselage housed the target banner, and a large windmill was fitted on the starboard fuselage side to power the winch.

The first prototype Target-tug aircraft (DR863) was delivered on 31 January 1942. 150 Mk II aircraft were also converted to Target-tugs, under the designation T.T. Mk I. A similar conversion of the Mk I was carried out by Reid & Sigrist from early 1942 under the designated T.T. Mk III. Nearly all the Target-tugs were withdrawn from service during 1945, although one example lasted until 27 February 1947.

Newly built Defiants awaiting delivery.

Another, less publicised, task of the Defiant was in the radar jamming role. 515 Squadron operated at least nine Defiants fitted with 'Moonshine' or 'Mandrel' radar jamming equipment in support of USAAF 8th Air Force daylight bombing raids on Germany between May 1942 and July 1943, before replacing them with larger aircraft types.

One Defiant T.T. Mk I (DR944) was seconded to Martin Baker on 11 December 1944. It was fitted with the first ever Martin Baker ejection seat in the observers station, and commenced dummy ejection trials on 11 May 1945. Another Defiant (AA292) was later used for similar trials by the Air Ministry until March 1947. Martin Baker retained their Defiant until 31 May 1948.In addition 150 MkIís were converted to TT.MkIIIís and 140 new production TT.MkIís were built to bring total construction, including prototypes, to 1,065 when production ended in 1943.

At the peak of its deployment as a night fighter, Defiants equipped 13 RAF squadrons. They were used subsequently at home, and in the Middle and Far East, as target tugs, and in addition about 50 MkIís were modified for use on the Air Sea Rescue role, serving with Noís 275, 276, 277, 280 and 281 squadrons.


Type: two-seat night fighter

Powerplant: (MkII): one 1,280-hp (954-kW) Rolls-Royce Merlin XX inline piston engine.

Performance: maximum speed 313mph (504km/h) at 19,000ft (5790m); cruising speed 260mph (418km/h); service ceiling 30,350ft (9250m); range 465 miles (748km).

Weights: empty 6,282lbs (2849kg); maximum take-off 8,424lbs (3821kg)

Dimensions: span 39ft 4in (11.99m); length 35ft 4in (10.77m); height 11ft 4in (3,45m); wing area 250sq ft (23.23m≤).

Armament: four 0.303in (7.7mm) machine guns in power-operated dorsal turret.

Development History:
first prototype One aircraft with 1,030 hp Merlin I engine. Turret not fitted initially.
second prototype One aircraft with 1,030 hp Merlin II engine. Several detail changes - much closer to production standard.
Defiant F. Mk I Initial day-fighter version.
Defiant N.F. Mk I Night-fighter conversion of F. Mk I. Flame damper exhausts, no radar.
Defiant N.F. Mk IA Night fighter conversion of F. Mk I with AI Mk IV or VI radar fitted.
Defiant Mk II prototypes Two F. Mk I aircraft fitted with 1,260 hp Merlin XX engine, increased fuel capacity, larger rudder and deeper oil cooler and radiator.
Defiant N.F. Mk II Production version of improved day-fighter version with 1,260 hp Merlin XX engine. Same designation with and without radar.
Defiant T.T. Mk I Version of Mk II for Target-tug role with turret removed and winch installed. New production and 150 conversions.
Defiant T.T. Mk II Projected version of Target-tug with 1,620 hp Merlin 24 engine and loaded weight reduced to 7,500 lb.
Defiant T.T. Mk III Version of Mk I converted for Target-tug role with turret removed and winch installed. 150 conversions.
Defiant ASR Mk I 76 conversions of Mk I aircraft for Air-Sea Rescue role.
Defiant Conversion of at least 9 Mk II aircraft for radar jamming role with 'Moonshine' installed.
Defiant Conversion of several Defiants for radar jamming role with 'Mandrel' installed.
Defiant Single-Seat Fighter Projected conversion with turret space faired over and armament of two 0.303 machine guns in each wing. Mock-up up built by converting first prototype, but no production.
Defiant Trainer Projected dual-control trainer version with turret replaced by second cockpit. Design work stopped when 80% complete.
P.85 Projected naval fighter version of F. Mk I with Bristol Hercules or Merlin engine, but Blackburn Roc ordered instead.
P.94 Project for improved single-seat fighter version with Merkin XX engine, cut-down rear fuselage and wings equipped for 12 machine guns or four 20 mm cannon + 4 machine guns.

Boulton Paul Defiant II AA666

Built by Boulton Paul Ltd at there Wolverhampton factory as part of a batch of 270 Mk I and II's. It was probably issued to either 264 or 141 squadron and probably converted to a TTI later in its life. There is a possibility that it served in India with one of the Air Gunnery schools and may have finally been struck off charge sometime between 1945 and 1947.

Additional aircraft of Interest

As can be seen these aircraft are not sons of Damien although they do tie in to another aspect of my site that being Battle of Britain Film survivors. During the making of the film the Spitfires used were given non-Spitfire serial numbers. They were in fact previously allocated to Boulton Paul Defiants I have thus chosen to illustrate them below. As the reader may be aware the ĎNí series of registrations were allocated twice although the first allocation for an order of 75 Norman Thompson NT2bís was cancelled.

 Norman Thompson NT2b

Boulton Paul Defiant I N3313

Built by Boulton Paul Ltd at there Wolverhampton factory as part of a batch of 161 Mk I. Served with 456 Sqn RAAF under RAF Control, 10/09/41 to 15/11/41. To 43 Group Depot (Ex-264Sqn RAF). This serial number was carried by the following aircraft during the film 'The Battle of Britain': - FVb BL614 which was used in the taxying scenes and by HFIXb MH434, which flew with this serial number.

Boulton Paul Defiant I N3318

Built by Boulton Paul Ltd at there Wolverhampton factory as part of a batch of 161 Mk I. This serial number was carried by the following aircraft during the film 'The Battle of Britain': - LFVb AB910 and FXIVc RM689, both aircraft flew with this serial number.

Boulton Paul Defiant I N3328

Built by Boulton Paul Ltd at there Wolverhampton factory as part of a batch of 161 Mk I. N3328 arrived at No.151 Sqn on 12 December 1940 and stayed until 22 August 1941, after serving with various units it crashed in a hailstorm on 24 October 1942, it was being flown from RAF Manby, in Lincolnshire, to Number 10 Air Gunners School at Barrow-in-Furness. The pilot, Sgt J L Coulter RAAF was sadly killed. The wreckage of this aircraft was dug up by the Lancashire Aircraft Investigation team (LIAT). In total about a ton of wreckage was removed from the site and several pieces, such as the instruments, were cleaned and donated to a museum at Millom, in Cumbria, connected with Number 10 Air Gunners School.

Of further interest is that during the film 'The Battle of Britain' this serial number was carried by two aircraft allegedly depicting Spitfire Mk I's. Namely, Spitfire LFIXc MK356 and Spitfire PRXIX PS915 they did not fly with this serial but were used for static shots.

Back to top

Home | Full Contents | Bibliography


Click on image to view

Click on image to view

Click on image to view

Click on image to view

Click on image to view

Click on image to view

Click on image to view

Click on image to view

Click on image to view

Click on image to view