Boulton Paul Defiant

[AnkitaMishra]

"It was a bomber destroyer and in 1935/36 when the idea was produced, no one thought that Germany would invade France and be able to use single seat fighters to escort bombers into British airspace."

This is of course total nonsence.

It was predicted that France will be attacked by Germany and when Defiant will be used it could probably be attacked by enemy fighters. Defiant supporters predicted that it will be successful.

I dont know if anybody predicted that Defiant could be mixed with long range fighters like Bf 110C, but this was also possible at the end the 1930s. We need to know original documents to make any final statements towards Defiant expectations in combat.

 

[buffnut453]

It was accepted that Germany would attack France. It was totally unforeseen that France would be overrun at all, let alone the lightning collapse that came to pass. The expectation was that any German offensive would be stalled, leading to a repeat of the static trench warfare of 1914-18. Maybe that expectation was foolish but, numerically, the French army was more than sufficient to absorb and successfully respond to a German offensive. What changed was the tactics which drove through French positions, with resultant collapse in morale.

 

[Shortround6]

"It was a bomber destroyer and in 1935/36 when the idea was produced, no one thought that Germany would invade France and be able to use single seat fighters to escort bombers into British airspace."

This is of course total nonsence.

It was predicted that France will be attacked by Germany and when Defiant will be used it could probably be attacked by enemy fighters. Defiant supporters predicted that it will be successful.

I dont know if anybody predicted that Defiant could be mixed with long range fighters like Bf 110C, but this was also possible at the end the 1930s. We need to know original documents to make any final statements towards Defiant expectations in combat.

While documents would be very helpful we also have to remember that the aerial landscape was changing at a very rapid pace. And British development was a bit on the slow side. From initial requirement to combat use in 1940 took about 5 years for the Defiant.
When the prototype Defiant first flew less than a dozen Bf 109s had been fitted with DB engines. Bf 110 production was at a creeping pace with Jumo 210 engines while they waited for DB 600 series engines in late 1938. The British were overtaken by events. Slow development/testing combined with orders being placed before testing was completed meant large amounts of materials and tooling was already in the production pipeline.

From wiki so subject to correction. " On 28 April 1937, an initial production order for 87 aircraft was received by Boulton Paul for the P.82; as this was prior to the first flight of the prototype, the aircraft had effectively been ordered 'off the drawing board'

"By January 1940, over half of the original production batch had been completed.[9] Beyond the initial production order in April 1937, follow-on orders had been issued for the type; in February 1938, an additional 202 Defiant Mk I aircraft were ordered; three months later, another 161 aircraft were ordered.[9] In December 1939, yet another 150 aircraft were ordered, raising the overall total to 513. In 1940, this rose to 563 Defiant Mk Is on order, while a further 280 were ordered under a rearranged manufacturing plan issued in mid-1940"

Basically you had 450 Defiants on order before the First production example flew.

Even in 1938 the bulk of the 109s produced used Jumo 210 engines (and 235-270 ? liter fuel tanks) and were armed with four or fewer 7.9mm MGs.

People had little doubt the Germans would attack France, the doubt was how far they could advance and how close they could push the airfields used to attack England.

 

[GregP]

As for naval terms, aircraft were saddled with port and starboard, instead of left and right, pilots and squadrons, as mentioned above, and even echelon formations from the Navy.

At least the relief tube wasn't a Navy term, and neither was bomb bay. Plenty of people used to shimmy out onto the catwalk to relive themselves when flying B-17s. I'd be VERY surprised if other bombers didn't do the same.

One wonders about bomb-bay relief in a P-51 for a 7- hour mission! Hopefully there was a something other than "wet-the-floorboard!"

And nobody had to climb the mast!

 

[stona]

I dont know if anybody predicted that Defiant could be mixed with long range fighters like Bf 110C, but this was also possible at the end the 1930s. We need to know original documents to make any final statements towards Defiant expectations in combat.

I have posted exactly that sort of information in another thread...somewhere. The documents I posted included a discussion of the tactics to be employed by the Defiant against bombers, tactics that could never have been considered in the presence of escort fighters.

The Bf 109 had a radius of operation of barely 150 miles (basically flying there and back and not indulging in any high demand combat flying). Nobody had envisaged the fall and surrender of France, it certainly wasn't considered in any of the RAF's 'War Plans', and nobody expected the Luftwaffe fighters to be operating from bases on the Channel Coasts of France and the Low Countries.

The first Bf 110s entered production in April 1938 just eight months AFTER the Defiant prototype first flew. British pre-war development times were long, which is why the type didn't enter production until mid 1939. Hindsight is a wonderful tool.
The DB 601 powered Bf 110 C variant did not begin to reach operational units until the summer of 1939, around the time the Defiant entered production.

Cheers

Steve

 

[stona]

It's probably worth mentioning that as of 29th June 1940, following earlier losses, the Luftwaffe could field 357 Bf 110s and that by the end of September it would have lost 235 of these destroyed (214 by enemy, that is British, action) representing 66% of initial strength. Operating in heavily contested enemy airspace against a well organised defence revealed the shortcomings of the Bf 110 in its intended roles. The Defiant was not the only fighter type unable to survive in the hostile aerial environments of the Battle of Britain. Coincidentally, both enjoyed some success as night fighters.
Cheers
Steve

 

[Shortround6]

Actual performance of production military aircraft in the late 30s was often secret, even pictures sometimes took a while to surface so unless there was a very good spy network capabilities were often unknown. And with 3-5 year development cycles getting caught short was all to often an occurrence if you were designing to what your opponents already had vs what you thought they might have 3-5 years down the road.
I am actually hard pressed to think of a single aircraft that was designed as a response to another aircraft already in service during WW II. Modified or improved versions yes, but an all new aircraft?

 

[stona]

I am actually hard pressed to think of a single aircraft that was designed as a response to another aircraft already in service during WW II. Modified or improved versions yes, but an all new aircraft?

I don't think that there were any. The pace of development precludes it. It may have been a factor in the 'concept-less' ordering by the RLM of aircraft off the drawing board?
The Defiant was not the first, and it won't be the last, weapons system that was proven incapable of meeting expectation once it was tested against a real, live enemy.
Cheers
Steve

 

[pbehn]

During the full period of the Battle of Britain the LW lost all of its front line strength (in numbers) of Bf110s. The strength at the end of it represented how many had been produced in the same period. However the same is pretty much true for RAF single engined fighters. The difference is that the British were more than replacing losses in machines and most importantly were achieving their aim of thwarting their opponent. A twin engined heavy fighter had its uses but escort fighter wasn't one of them.

 

[stona]

The RAF made a net gain of 261 Hurricanes and 175 Hurricanes between 6th July and 2nd November 1940. Production far outweighed losses with the exception of a few weeks in August/September. The loss of 537 airmen, mostly pilots, was a much bigger problem for the British. Here the advantage of fighting over friendly territory was vital. It has been calculated that 501 Squadron, which fought for most of the period in 11 Group, sustained 47% casualties (nineteen killed, eleven wounded), but, had those shot down who returned to the squadron not been able to do so, this figure rises to an unsustainable 72%. For example, the squadrons top scorer, James 'Ginger' Lacey, baled out and survived to fight again no less than three times during this period!

The best figures for losses on both sides are those in 'The Battle of Britain Then and Now' (page 705 of my edition). The RAF lost 1,023 aircraft, the vast majority single engine fighters, the Luftwaffe 1,887 of which 873 were Bf 109s or Bf 110s. Just about every source will give slightly different numbers, but the overall result is always similar.

The Bf 110 losses were over 2/3 of initial strength, but actually close to 100% (some give 94%) of operational strength at the beginning of the Battle. Operational ready rates for the Bf 110 were not great following the campaigns prior to the BoB.

Cheers

Steve

 

[pbehn]

The RAF made a net gain of 261 Hurricanes and 175 Hurricanes between 6th July and 2nd November 1940. Production far outweighed losses with the exception of a few weeks in August/September. The loss of 537 airmen, mostly pilots, was a much bigger problem for the British.

That was precisely my point. Dowding insisted on a base minimum of 500 single engined fighters with pilots, the LW actually destroyed that many or killed/injured that number of pilots. In numbers the RAF was stronger and the LW weaker, pilot skill and training is a different issue. As far as the Bf110 is concerned it cost much more to build and operate than a Bf109 and none of the extra cost was justified by results

 

[stona]

Luckily for Fighter Command it only operated two squadrons of Defiants, Nos. 141 and 264 during the Battle. They claimed 22 Luftwaffe aircraft, but for the loss of 28 aircrew, a figure made worse by the Defiant's crew of two. To put that negative ratio in perspective, the average Hurricane squadron claimed 5.7 aircraft for every pilot lost and the average Spitfire squadron 7.4.
If we accept the total Luftwaffe losses as 1,887 aircraft and Fighter Command aircrew losses at 537 the actual overall ratio is about 3.5 aircraft destroyed for each pilot lost, so the claims are unsurprisingly optimistic. The more important figure is that for every RAF aircrew killed the Luftwaffe lost nearly 5, with many more captured and removed from the fray.
Cheers
Steve

 

[buffnut453]

I am actually hard pressed to think of a single aircraft that was designed as a response to another aircraft already in service during WW II. Modified or improved versions yes, but an all new aircraft?

I agree. The only one that comes close might be the Westland Welkin specifically designed for high-altitude interception...but that's still more of an operational capability gap than it is a direct response to an adversary aircraft. Of course one could argue that the Welkin was simply an "improved" version of the Whirlwind.

 

[swampyankee]

The Defiant was the result of a bad specification, in the same way as were the Blackburn Roc, the Bell Airacuda, and the Messerschmidt Me110. Of the three, only the Bell aircraft was discarded before it entered combat. The Me110 had value in roles where maneuverability was not so important, such as night fighting, but the Defiant wasn't able to carry the radar needed to be a completely effective night fighter, at least in 1940 and 1941.

As an aside, please don't claim that a twin-engined fighter could not be competitive in 1940: I think that the specifications of the Whirlwind showed that a twin-engined fighter could be effective in air combat, but only if that was the main design goal. If I remember, the goal of the specification for the Me110 was as an escort aircraft to ward off enemy fighters, analogously to destroyers in naval usage.

One of the problems with any discussions of this sort is that the errors in specification -- which are largely responsibility of the using services -- are conflated with errors in execution.

 

[Ascent]

During the Battle of Britain it wasn't just new build aircraft the RAF were getting, they had a very efficient repair organisation putting aircraft back into the air that had received significant damage. It meant many fighters that might have been constructive losses were back in the air before the end of the battle.

 

[stona]

The Specification for the Defiant is only 'bad' with hindsight. In the early and mid 1930s the RAF had severe doubts about the the effectiveness of fixed gun fighters, even with eight or ten machine guns, against formations of bombers.
Salmond, then AOC-in-C Air Defence of Great Britain clarified the issue in 1933 when he wrote

"I would suggest that the fixed gun single seater, which is the cause of this pessimism, was designed in the first instance rather for the needs of air fighting in France in 1916-18 than for the purpose of home defence fighting."

In order to break up enemy formations in the short time available Salmond suggested that

"the design of the home defence fighter and the tactics employed should be such as to produce the maximum of fire effect in the minimum time."

To get the concentration required would require the attacking aircraft to make their attack in formation, and this ruled out fixed gun fighters, because

"A pilot cannot aim a gun and at the same time accurately maintain his position in formation."

It is these perfectly reasonable arguments, at the time, which led to the development of the specifications which would result in the Defiant. By April 1935 the Operational Requirements Committee were discussing 'Air Staff Requirements for a Single Engine Two-seater Day and Night Fighter'. The resulting Air Staff requirement showed the quandary resulting from the desire to have a multi seat fighter in conjunction with a failure to agree viable tactics for its use. The Requirement called for a fighter which

"..can bring fire to bear from a moveable battery of at least four machine guns over the upper hemisphere...; thus conferring on it the ability to attack from below and behind, below and in front, or on the flank of an enemy formation, at the same time enabling the batteries of all fighters to be trained on to the target simultaneously while in formation."

The draft F.9/35 was approved by Ellington and circulated to industry that month, a full specification followed in May, and the Defiant was ordered in 1938. By the time it entered service two years later, viable tactics for its employment had still not been worked out, and the rapid development of aircraft elsewhere had rendered it virtually useless as a day fighter.

Cheers

Steve

 

[Shortround6]

The trouble with this theory was that it rather ignored all the experience of WW I. Quite a few fighters had flexible guns even if not turrets operated by a second crewman but the weight penalty of the second crewman almost always negated the advantage of gun flexibility vs the single seat fighter using fixed gun/s.
Britian's most successful 2 seater, the Brisfit, was only successful when flown as a fighter 'with a sting in its tail ' rather than depending on the rear gun/s as the primary means of attack. And quite a few of these F2b's had two guns in the rear and only one fixed gun out the front.
The F2b also used a more powerful engine than well over 90% of the single seat fighters.
Perhaps if the Defiant had been powered by an early Griffon?

One also needs to consider ALL likely targets, not just ones favorable to the concept. For instance the Defiant would have probably been successful against a bomber like the Whitley but of rather limited use against a fast bomber like the Do 215, this assumes the use of similar engines in the interceptors and the bombers.

 

[stona]

The trouble with this theory was that it rather ignored all the experience of WW I.

Not in this context. Fixed gun fighters in WW1 engaged other aircraft in much the same way as they would do in WW2, but this was not expected to be the case when fighters were confronted by the large and heavier bomber formations expected by the 1930s. The RAF's emphasis, in the context of a home defence fighter, which would be expected to engage these bomber formations, was on achieving a sufficient weight and concentration of fire to shoot them down in the short time available. This is why a second crewman to man the guns while the fighters made a formation attack, flown by the pilots, was considered imperative. The concept of turret fighters, not just those with the Defiant midships turret configuration, dates back to the early 20s, only becoming practical in a single engine aircraft in the 1930s. Most if not all the earlier proposals (I haven't checked) were twins.

In the 1930s two principal factors drove British fighter design, the quest for firepower and the quest for speed. The Defiant was the result of the former, the Spitfire and Hurricane of the latter.
The submission of a Hawker monoplane fighter, which would become the Hurricane, was a direct result of the Director of Technical Development's (I think it was Henry Cave at the time) 1934 decision that both Hawker and Supermarine developments should be dealt with, meaning financed, as part of the ongoing high speed research programme.

Cheers

Steve

 

[AnkitaMishra]

It was accepted that Germany would attack France. It was totally unforeseen that France would be overrun at all, let alone the lightning collapse that came to pass. The expectation was that any German offensive would be stalled, leading to a repeat of the static trench warfare of 1914-18. Maybe that expectation was foolish but, numerically, the French army was more than sufficient to absorb and successfully respond to a German offensive. What changed was the tactics which drove through French positions, with resultant collapse in morale.

I DONT THING, that this expectation have anything to do with Defiant and its tactics when used with Spitfires support on 13th May 1940 on the battlefield. On this day, nobody knows, that Belgium and France will collaps soon. Defiants were belived to survive under the protection of 8-gun fighters, but they failed misserably on the very first occasion.

 

[AnkitaMishra]

I have posted exactly that sort of information in another thread...somewhere. The documents I posted included a discussion of the tactics to be employed by the Defiant against bombers, tactics that could never have been considered in the presence of escort fighters.

The Bf 109 had a radius of operation of barely 150 miles (basically flying there and back and not indulging in any high demand combat flying). Nobody had envisaged the fall and surrender of France, it certainly wasn't considered in any of the RAF's 'War Plans', and nobody expected the Luftwaffe fighters to be operating from bases on the Channel Coasts of France and the Low Countries.

The first Bf 110s entered production in April 1938 just eight months AFTER the Defiant prototype first flew. British pre-war development times were long, which is why the type didn't enter production until mid 1939. Hindsight is a wonderful tool.
The DB 601 powered Bf 110 C variant did not begin to reach operational units until the summer of 1939, around the time the Defiant entered production.

Cheers

Steve

I was talking about real combat experience and engagements. On 13th May 1940 Defiants were supported by Spitfires from 66 Squadron and involved in combat with Me 109s. They failed misserably! This is the exact confirmation of believe, that Defiants could survive being protected by single engine fighters towards enemy fighters. RAF Staff believed in it even after Dunkirk! Defiant was withdrawn from daylight combat area only after 28th August 1940 disaster number x.... This is how stupid RAF high officers were and how they believed in Defiant effectivity. Its just like now with politicians, they did not want to confess to big mistake and failure. If you beat politician in his head, he will confess, otherwise NOT