Boulton-Paul P.82 Defiant


Back to the Virtual Aircraft Museum
  FIGHTERVirtual Aircraft Museum / United Kingdom / Boulton-Paul  

Boulton-Paul P.82 Defiant

At a time when prototypes of the famous eight-gun fighters for the RAF - the Hurricane and Spitfire - were being built, the British Air Ministry thought up a new tactical concept for a two-seat fighter. This was to be crewed by a pilot and air gunner, the latter provided with a power-operated turret, in the belief that both crew members would be able to work more effectively. Boulton Paul and Hawker both submitted design proposals and built prototypes, the Defiant and Hawker Hotspur, but it was the former which was ordered into production. A cantilever low-wing monoplane of all-metal construction, the Defiant had a Boulton Paul power-operated turret containing four 7.62mm Browning machine-guns.

The prototype flew for the first time on 11 August 1937, entered service in December 1939 and was used operationally by No 264 Squadron for the first time on 12 May 1940. Defiants were an immediate success; unsuspecting enemy aircraft making a conventional attack from the rear were subjected to the concentrated fire power of the four Brownings. Within 19 days Defiants were credited with the destruction of 65 aircraft - 38 on one glorious day. Unfortunately for the British, the Luftwaffe pilots were quick to realise there were certain sectors at which the battery of machine-guns could not be directed. Thereafter they were subjected to attack from below or head-on, against which they had no defence, and they were quickly taken out of front-line daylight service. There was a further brief spell of success in the night fighter role, during the winter of 1940-41, after which Defiants were used largely for target-towing, air/sea rescue, army cooperation and gunnery training.


The Defiant Mk I was powered by the same Merlin engine as the contemporary Spitfire and Hurricane models, but was larger and considerably heavier.

All the Defiant's weapons were in the charge of the gunner, it being thought the pilot could better fly the aircraft without having to concentrate on aiming at a target.

In the Mk II model, a more powerful Merlin was fitted, as was a larger rudder. Many were converted to target tugs and others were used for air-sea rescue work.

Boulton-Paul P.82 Defiant

 ENGINE1 x RR "Merlin III", 645kW
  Take-off weight3765 kg8300 lb
  Empty weight2757 kg6078 lb
  Wingspan12.0 m39 ft 4 in
  Length10.7 m35 ft 1 in
  Height3.5 m12 ft 6 in
  Max. speed489 km/h304 mph
  Ceiling9200 m30200 ft
  Range750 km466 miles
 ARMAMENT4 x 7.62mm machine-guns

Boulton-Paul P.82 DefiantA three-view drawing (800 x 694)

Comments1-20 21-40
Kevin Coleman, e-mail, 17.12.2020 23:12

The key point is that the Defiant was not designed to meet fighters, it was supposed to attack bombers, slower and clumsier and equally, not expected to mix it with defending fighters. The German air force pilots insisted on escorting fighters being close at hand which reduced their fuel efficiency -- they could make only one pass at defending R A F. craft. One thing I've noted is that no-one has mentioned the little crank-handle with which the gunner was expected to wink the near-half ton turret round, if the hydraulics, vulnerable to a single rifle-bullet, got disabled. Not a happy story, which cost many good lives.


Percy Eggbowellman, e-mail, 06.04.2016 14:53

Mr Rudniki's comment that the Merlin engines used on the defiant could be have been better used on the Westland Whirlwind fighter has merit, The Mustang achieved it's full potential when fitted with Merlins and the Whirlwind with minor modifycations could have accomodated these engines and gone on to establish a fearsome reputation against the German Air Force as well.


Les.Whitehouse, e-mail, 07.08.2015 11:23

Unfortunately any detailed discussion on the Defiant requires much more space than available here. The story about the turret not having space for a parachute is simply not true. Neither did any gunners report difficulty in bailing out. The 264 sqn deployment (Holland and Dunkirk) had pilots and gunners with Mae West and parachutes. The gunners was a lap chute (as in many bombers) stowed to starboard in the underframe of the rotating turret ring. Some time between mid June and August 1940 the RAF decided that the new GQ Parasuit was a good idea to try and withdrew normal chute /Mae West for the gunners. Issuing them instead with the Parasuit. However this application added at least 2 inches (50.8 mm) to the gunners girth at the back and required a MOD to remove the gunners backrest from the turret ring in order to fit. Since part of the gunners control table hinged to make the space larger it did not interfere with entry or exit when the table was folded. During the nightfighter era a much thinner backrest had to be added as MOD 211 because Parasuit's were fraying from contact with the turret ring. Non-operational crew frequently used both lap or back chutes.


paul spilsbury, e-mail, 30.01.2015 23:45

The Defiant was built to shoot down bombers not fighters whilst hurricanes and spits took care of the escorting 109's. But in the months leading up to the battle of britain(due to a lack of our fighters) in desperation by Dowding, they were sent out on occassion unescorted.
264 squadron used an ascending spiral tactic so each aircraft protected the other and were the more sucessful squadron.but 141 squadron had no such defensive tactic and got a battering. As there were two crew per aircraft the losses were doubly felt at a critical time and they were withdrawn further north to do night fighter against bombers.Dont forget there were only 1000 built but shot down over 100 aircraft (Hows that ratio of kills compared with other fighters dont forget there were 36.000 spitfires )for which the squadron was awarded a silver salvour enscripted and presented by the boulton paul company(I have held this salvour its real )264 squadron shot down 37 over dunkirk ok mainly because they caught the 109's by surprise with the turret but I dont think the guys up to their chests in water on the beaches minded.Yes the design of the turret(unable to bailing out)was a terrible flaw but they did not deserve the bad press during the war which blighted them to a degree that they are NEVER mentioned in war films or documentry's at all.I have recently received from the RAF information that the Dornier removed from goodwin sands quite possibly was shot down by a Defiant

Dear Mr. Spilsbury,

Thank you for your enquiry, which we received on 11 January.

We can confirm that Boulton Paul Defiant L7005 was involved in a combat with Dornier Do. 17s on 26 August 1940, while on patrol between Herne Bay and Deal in Kent. Our records also show that the crew made claims for two Do. 17s and a Messerschmitt Bf. 109 shot down, while other members of the squadron claimed a total of six more Do.17's destroyed and one damaged. However, our records do not provide any identification for the individual German aircraft claimed by any of the RAF aircraft involved, or details on the crash sites. At the end of the combat, L7005 was forced to crash land at Herne Bay due to damage received.
But of course its not the done thing to praise the Defiant


Rick Ash, e-mail, 02.01.2014 22:39

I read that wrong tactics were used when attacked by Me 109's.
Air aces over France during the early fighting suggested that a luftberry (sp?) circle be used to combat 109's. I think this would have made a big difference.


Trevor Webb, e-mail, 20.12.2013 13:39

The guns used in the Boulton Paul four gun turrets wew Browning 7.7mm (.303)not 7.62mm (.30). 7.7 was a British calibre while 7.62 was American. One defiant was completed with a different turret with a 20mm Hispano cannon.


VinceReeves, 05.03.2013 21:17

The Defiant achieved 65 kills as a night fighter, which was a reasonable tally for the period. It pioneered ECM countermeasures, which was probably its greatest achievement. It was also an unsuccessful ASR aircraft, but a successful target tug. They were still making them, all be it at low volume, in 1943.

It was, for all the controversy that surrounds it, a good aircraft.


Kevin Coleman, e-mail, 17.12.2020 VinceReeves

It was not a good aircraft. It was too heavy for its power-plant so it didn't climb well, it wasn't manoeuverable enough, didn't pack much of a punch, and needed two good blokes to crew it. And they needed to believe in the type, which was debatable at best.


Klaatu83, e-mail, 05.03.2011 04:14

A good airplane, developed to satisfy a mis-conceived operational requirement.


Angus McDonald, e-mail, 26.01.2011 01:49

I have always felt that the Defiant could have been developed into a Mustang style fighter three years before the Mustang came to fruition. With the turret removed and longer range petrol tanks and Hurricane style front firing guns fitted it might have been a winnner. But the bureaucrats won on this. Boulton Paul did develop prototype single seater development on these lines but nothing came of it.
I read somewhere that a Defiant was sent to the USA for study, but who by and why was not mentioned. I have always wondered how the Mustang came to be developed from scratch to flight in 100 days, and at the resenblance of the early Mustangs to the Defiant profile, and whether the Mustang designers used the Defiant as a basis for their design.


Kevin Coleman, e-mail, 17.12.2020 Angus McDonald

The Mustang was developed as the P-51 for the United States, and not much of the famous hundred days would have been spent evaluating a limey aircraft which was the only two-seater around


Barry, 21.01.2011 16:51

If you could turn the turret round, which you could not, you would only acheive in shooting the propellor off. As for the other suggestion of arming with 2 cannon and 4 machine guns in the wings, as well as the turret and a crew of two, I doubt if the plane would ever get off the ground. If you want a plane armed like that get a Beaufighter. At the end of the day you cannot attack by flying away from a target. As ever Leo Rudncki has got this right. It takes a long while for our idiot civil servants to get things right, but one has to admit that both the Defiant and the even more awful Roc were really so wrong. What gets me is people like this are still in control.


Robert Maxwell, e-mail, 11.11.2010 23:42

My understanding is that, though the airplane had no fixed forward-firing armament, the turret could be rotated 180 degrees through the vertical and all guns could fire forward. Of course, even if this is true, four .303 Brownings mounted in a heavy two-seat fighter, aren't very intimidating.


Jackie, 08.08.2010 11:33

The Boultan-Paul Defiant proved that the turret fighter design was a bad one. Entering service in late 1939, the defiant was good at the beginning because the luftwaffe pilots mistakenly believe that this was a Hawker Hurricane and approached them from the rear. The rear gunner easily shot the Messerschimitt-109 to bits. However, the luftwaffe pilots later learnt to attack from below or headon. The Defiants were removed from combat duties in 1942 and used for training, target towing and air-sea rescue.


Ian Roberts, e-mail, 29.03.2010 15:30

Apparently the gunners suffered high loss rates due to difficulty in escaping: The gunner's hatch was in the rear of the turret, which had to be rotated to one side or the other to enable entry or 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 nick-named 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"


BOB NORTON, 26.10.2009 21:10

David I did not have any dought that it was a good night fighter after all it was the first plane to carry air intercept radar. I was interested in what tactics were used. Leo has given his thoughts but i do not know if they are facts?


David Munroe, e-mail, 10.10.2009 20:01

Paul Scott, you are so right. This is one of my favourite aircraft of all time. It looks good, destroyed a lot of 109s who mistook it for a Hurricane in the early days of the war, did a great job as a night fighter, but the cowards behind the desks failed, yet again, to give the crews the complete kit for the job. Me, I would have fitted two cannon and four machine guns in the wings, firing forward, and then just the Fritzies come to be cooked. This plane could have been one of the war winners. And I can't be convinced, sorry Leo and Bob, but it did have success as a night fighter. How do I know? One of my uncles flew one. Who do you know that did? Nothing personal. The whole corrupt state of British politicians and ministries, from Air to Ground to Naval condemned a great many of our forces to death through successions of ignorant decisions, greed and envy.


paul scott, e-mail, 18.08.2009 18:52

I still couldn't believe the Air Ministry AND Boulton Paul couldn' see this one coming. A good start but leaving out at least, frontal armament. Big mistake!


geoff, e-mail, 14.08.2009 16:24

where can I get a sectioned view drawing of a DEFIANT


Leo Rudnicki, e-mail, 20.07.2009 05:15

The phrase "limited success as a night fighter" is a war-time myth to prevent embarrassment to the Air Ministry for ordering it in the first place as well as continuing production after its uselessness was known. It also earned limited success spotting for Walrus air /sea rescue aircraft but it's real success was as a target tug. A waste of a thousand Merlin engines at a time when De Havilland had to beg for two, and the Whirlwind might have been something. There were never enough night interceptions to emulate the Schrage Musik style of interceptions and German bombers all had ventral guns to thwart such an attempt. Also, I believe the high success rate for early use as day fighter resulted from multiple claims, with multiple gunners firing on the same target and all claiming the same victory.


BOB NORTON, 12.07.2009 19:00

This death trap of a day fighter had limited success as a night fighter, did they attack from below a bomber and use its guns like Schrage Musik (Jazz Music) as on some German night fighters? THANKS.


David Munroe, e-mail, 20.04.2009 04:56

This aircraft was let down by the planners and designers. A fighter attacks, straight point of existence. An escort fighter both attacks and defends. This plane fitted with the same forward armaments of the Spitfire and the Hurricane would have been the answer to many problems at that time. The brave men who went up in the aircraft chosen by the Air Ministry were let down time and time again. This plane COULD have stopped anything the Nazi war machine had if it had been treated as a proper fighter at the right time, and given the weapons to do the job


1-20 21-40

Do you have any comments?

Name    E-mail


All the World's Rotorcraft

All rhe World's Rotorcraft AVIATION TOP 100 -