Success of Defiant as night fighter?

stona said:

Nor were nightfighters unless being vectored onto a target,which could not be the case before an integrated night time air defence system was established. Until then,to paraphrase Dowding,they were simply flying around over London hoping that a target might turn up.

I agree that with the advent of a functioning,radar guided,command and control system the Defiant became a functional night fighter,but just about any aircraft could have been.

The Defiant was simply available in substantial numbers following its failiure to fullfil its intended role as a day time interceptor. It should be remembered that this failiure was due in part to the presence of single engined escort fighters in the Luftwaffe formations. Noone in 1939 imagined that France would be defeated and that such aircraft would obtain bases within range of mainland Britain.


Even then the speed advantage of a Defiant over a bomber cruising at 230mph made interception difficult as the RAF admitted in 1939,albeit in the context of daylight operations.

Cheers

Steve

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According to Wiki though, 210 Mk.II Defiant night fighters were produced in addition to the original day fighters, so it's not just a case of what type happened to be hanging around.

Apparently Alec Brew's "Turret Fighters" book states that the Defiant was intended as both a day and night fighter from the beginning. Tho' I got that from elsewhere on the net, and not from the book itself.

VinceReeves said:

Apparently Alec Brew's "Turret Fighters" book states that the Defiant was intended as both a day and night fighter from the beginning. Tho' I got that from elsewhere on the net, and not from the book itself.

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From RAF documents that I've seen the men at the sharp end don't seem to have had a clear idea of what to do with it,or any turret fighter. After the war had started they were still unclear as to how the Defiant might best be utilised. There were always reservations about its lack of performance.

Does A.M. specification F.9/35 mention a night fighter role? It may do,I have no way of checking at the moment.

Cheers

Steve

The Defiant was simply available in substantial numbers following its failiure to fullfil its intended role as a day time interceptor.

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No, that's not true at all; simply dismissing them because you don't like them is no reason to diminish their efforts. production of Defiants did not really get going until early 1941 or so, your generalisation doesn't cut it, Steve. There were not very many of them around at all in 1940, 1941. By the end of 1940 only a handful of squadrons were equipped with them and as a day fighter only two squadrons were equipped with them at any given time there was only one squadron of Daffys in combat. The highest number of Defiants that entered into combat at any one time was 12. normally flights of six or three at a time were sent out. As a night fighter they were sent out singularly, not in formation.

Defiants did not fail to fulfil their role as a day time interceptor at all; as you know, they were designed as bomber interceptors, not to mix with fighters, this was known by Dowding and those on the ground who used them and to say they didn't know what to do with them is simply rubbish; 264 Squadron's CO's efforts to train his polits in tactics to use their fighters to advantage against overwhelming odds is testimony to this. In the Battle of Britain it was used as a single-seat fighter was, carrying out convoy escort duties, standing patrols etc for which it was not designed. In the instances where Defiants were sent to intercept unescorted bombers they did well. Their performance in the BoB was not because they failed in their role as interceptors, but because they were placed in a role for which they were not designed and if FC heads had sense they should have placed them in the north where opposition by fighters was non-existent.

As for the statement that any aircraft could be a night fighter is also blatantly untrue. Perhaps the biggest deciding factor of what made a good night fighter was cockpit ergonomics and good visibility; the Spitfire made a poor night fighter, the Fw 190 was also not the best at night, they were fitted with autopilots as standard when used for night duties, as flying on instruments in them was tiring.

stona said:

From RAF documents that I've seen the men at the sharp end don't seem to have had a clear idea of what to do with it,or any turret fighter. After the war had started they were still unclear as to how the Defiant might best be utilised. There were always reservations about its lack of performance.

Does A.M. specification F.9/35 mention a night fighter role? It may do,I have no way of checking at the moment.

Cheers

Steve

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While I'm not certain about F.9/35, F.10/35, which covered the Spitfire, was framed as a requirement "A Single-Engine, Single-Seat Day and Night Fighter." Quite a few RAF specifications promulgated from 1931 to 1938-9 were for dual purpose day-night aircraft; part of the reason such specifications were issued was because of the experience of WW 1, when the British adapted several single seat and two seat diurnal aircraft (eg: Sopwith camels and Avro 504s) to night fighters. Sopwith Camel | Flight Archive Avro 504 - The Shuttleworth Aircraft Collection.

I think there is some truth to both positions.

In the mid 30s single seat fighters were both day and night fighters. They just weren't very good at night fighting. A "night" fighter was equipped with such things as landing lights and flare chutes to enable it to land at night and/or being equipped with a radio homing device to find it's own airfield. FINDING it's targets depended on luck, moonlight and good eyesight.

With the higher landing speed and poorer visibility of enclosed cockpit monoplanes compared to the older biplanes it was realized that not all fighters were created equal in regards to operating at night and some planes were going to suffer a higher accident rate operating at night than others. Forget even finding the enemy planes.

With the coming of radar what constituted a night fighter changed radically. However, because radar was changing so fast, what was thought to be needed as a night fighter in late 1939/early 1940 was not needed so much in in 1942/43.

The First practical British airborne radar went about 600lbs installed which rather ruled it out for single engine/ single seat fighters. Asking the pilot to manage the early radar in addition to flying the plane was also a bit much. However radar was progressing at a truly amazing rate. The British competed the installation drawings of the MK VI radar for the Defiant on Nov 19 1940. The Pilot was the radar operator. Due to moisture problems and bad electrical screening ( and some foot dragging?) it wasn't cleared for service until Aug 1941. Late Blenheims, Beaufighters and Havacs used MK IV radar. The MK VII centimetric radar was undergoing airborne testing in Nov 1941. A year earlier one "expert" had declared that centimetric radar was for the next war.

It is curious how certain people (not necessarily those who have posted here) say how clever the Luftwaffe was to put upwards slanting guns on their nightfighters yet also say how silly the RAF was to put turrets with upwards slanting guns on nightfighting Defiants.

As far as the firepower of the turret is concerned, 4 x.303" was considered by the world as a heavy turret defence in bombers in it's day. At the same time as it was designed Gladiators and Skuas were carrying the same 4 x .303". Fired without tracer at night the gunner could rake his target with a longer burst than a fixed gun fighter and from close enough for .303" to be as effective as it could. If the pilot had been trained, and given the sight for using the turret guns fixed forwards and upwards, he would have had a perfect no deflection target as was part of the original concept that got lost in personnel changes.

As the pilot was already trying to fly and operate the radar it was probably wise anyway to leave the gunnery to the gunner.

Of course the far larger and more powerful Beaufighter could carry a knock out blow with 6 x .303" as well as 4 x 20mm cannon but if you haven't yet got them you can't use them. In 1941 you had Defiants in production in quantity but Beaufighters were only just coming in.

There seems to be some confusion about the Defiant's radar set-up.

From what I can glean, there were two marks of AI-equipped Defiant: the Defiant NF Mk.IA, which initially had an AI Mk.IV (4) set, and the Defiant Mk.II, which had an AI Mk.VI (6) set.

It appears that the Defiant Mk.II didn't enter service until September 1941. I haven't seen any info on when the NF Mk.IA entered service, and in what numbers. Would it have been earlier? i.e April 41 when the number of successful interceptions appeared to increase drastically?

nuuumannn said:

Defiants did not fail to fulfil their role as a day time interceptor at all; as you know, they were designed as bomber interceptors, not to mix with fighters, this was known by Dowding and those on the ground who used them and to say they didn't know what to do with them is simply rubbish; 264 Squadron's CO's efforts to train his polits in tactics to use their fighters to advantage against overwhelming odds is testimony to this.

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In post #7 I posted a document from early 1940 which would imply that the RAF had no clear idea of how they would be able to use the Defiant.There is also no definite consensus on it's performance after four months of war.

Dowding appeared unsure on numerous occassions about what to do with it,or any turret fighter. He,Sorley et alter in the RAF and at the Air Ministry were proponents of the 6/8 fixed machine gun armed fighter like the Spitfire and Hurricane.

It did fail as a day light interceptor in the BoB despite the heroic efforts of the men condemned to fly it. The tactic proposed for them (flying a paralell course to an enemy formation,delivering raking or enfillade fire) are ridiculous and demonstrate again the lack of any clear idea as to how a turret fighter might be employed. The men at the operational units had enough sense to realise that this wouldn't work and did their best to develop tactics that could work.

It was,I think,Park who pointed out that the best position for a Defiant to engage an enemy aircraft from was the worst tactical position,infront and below. In this position the added problem was that the pilot could see neither what the enemy aircraft was doing,nor what his own gunner was doing.

Aircraft that succeeded as day time interceptors in 1940 were still flying as day fighters in 1942/3. The Defiant was not.

I'll qualify "any aircraft could be a nightfighter" as any aircraft with a peformance comparable to the Defiant,which was marginal,with enough room for the night fighting equipment (pretty much anything if the RLM considered the Fw 187) and preferably a crew of two.

As for night fighting,the A.M. specifications could not have envisaged,in 1935,the need for a nightfighter in the sense that we understand it now and that the airmen of 1940 meant it then. Bombing doctrine of the 1930s did not generally envisage large scale night time operations. Counter measures were not really developed pre-war,the technology hadn't been developed in any case.

People keep quoting the 210 Defiants built as nightfighters with no context. In the big scheme of British aircraft production this is a remarkably small number,particularly given the pressing need to develop some kind of effective defence to night bombing.

Cheers
Steve

stona said:

People keep quoting the 210 Defiants built as nightfighters with no context. In the big scheme of British aircraft production this is a remarkably small number,particularly given the pressing need to develop some kind of effective defence to night bombing.

Cheers
Steve

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Well, the 210 was in addition to Mk.I's being converted to radar equipped NF Mk.IA's.

So the context is that after these conversions it was considered worthwhile, for whatever reason, to augment their numbers with new production.

What we don't know yet is how many Defiant Mk.I's were converted to NF Mk.IA's.

But then this thread is long on opinions and short on facts.

VinceReeves said:

Well, the 210 was in addition to Mk.I's being converted to radar equipped NF Mk.IA's.

So the context is that after these conversions it was considered worthwhile, for whatever reason, to augment their numbers with new production.

What we don't know yet is how many Defiant Mk.I's were converted to NF Mk.IA's.

But then this thread is long on opinions and short on facts.

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I don't know how accurate this web sit is but lets try these "facts" unless somebody can show different.

Aeroflight » Boulton Paul Defiant

First radar fitted Sept 1941.

Defiant production in 1942 was a trickle. Production of the MK IINF stopped in Jan 1942. Production of the Defiant TT Mk I (target tug) went from late 1941 to Feb 1943 and totaled 140 planes, about 10 per month.

From a different source:
While 13 squadrons were equipped with Defiants for night fighting some of them were so equipped for rather short periods of time. One squadron was declared operational in mid August of 1941 on Defiants and received it's first Beaufighter MK II NF at the end of August.

Several pilots did make ace while flying Defiants.

Please note that as far as performance goes the Defiant is about 40mph ( or more) faster than the Blenheim night fighter. About the same speed as early Havocs and only about , in the MK II version, 15mph slower than a Beaufighter. Speed was not it's main problem.

While four .303 mgs may have been considered adequate in 1936-39 it was no longer adequate in 1940-41. NOBODY in 1940 was designing fighters (using them but not designing new ones) with only four rifle caliber machine guns. The turret may have enabled the Defiant to keep it's guns on target longer than a fixed gun fighter could but a fixed gun fighter with heavier armament could do more damage in a shorter period of time to begin with.

Shortround6 said:

I don't know how accurate this web sit is but lets try these "facts" unless somebody can show different.

Aeroflight » Boulton Paul Defiant

First radar fitted Sept 1941.

Defiant production in 1942 was a trickle. Production of the MK IINF stopped in Jan 1942. Production of the Defiant TT Mk I (target tug) went from late 1941 to Feb 1943 and totaled 140 planes, about 10 per month.

From a different source:
While 13 squadrons were equipped with Defiants for night fighting some of them were so equipped for rather short periods of time. One squadron was declared operational in mid August of 1941 on Defiants and received it's first Beaufighter MK II NF at the end of August.

Several pilots did make ace while flying Defiants.

Please note that as far as performance goes the Defiant is about 40mph ( or more) faster than the Blenheim night fighter. About the same speed as early Havocs and only about , in the MK II version, 15mph slower than a Beaufighter. Speed was not it's main problem.

While four .303 mgs may have been considered adequate in 1936-39 it was no longer adequate in 1940-41. NOBODY in 1940 was designing fighters (using them but not designing new ones) with only four rifle caliber machine guns. The turret may have enabled the Defiant to keep it's guns on target longer than a fixed gun fighter could but a fixed gun fighter with heavier armament could do more damage in a shorter period of time to begin with.

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Thanks. I think the Defiant "aces" were the overclaimers from 264 squadron during their operations in daylight.

As for armament, this is going to be an issue, and the Defiant will be significantly less effective than the Beaufighter because of it - the table in the Alfred Price book bears this out.

The point of this thread isn't to rehabilitate the Defiant, or make out it was as good as the Beaufighter etc. It's just to establish whether the lukewarm praise it has received as a nightfigher is justified. From what we've established so far, it is.

VinceReeves said:

But then this thread is long on opinions and short on facts.

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Well the opinions of Dowding and the Wing Commander Armaments which I posted from original documents are not my opinions. I would consider their "opinion" of the Defiant relevant.They both considered the speed of the Defiant to be insufficient and were already contemplating "relegating" it to night time operations before the BoB even started.

I happen to agree that it made a decent stop gap nightfighter,given the relative abilities of such aircraft and their technologies at that time.It was very soon superceded by aircraft better fitted for the task. That's about it though in my opinion.

Cheers

Steve

Lets remember that about all it took in 1940 for a plane to be a "night fighter" was a coat of black paint and some shrouding/sheilding of the exhaust pipes, in some cases just enough to avoid blinding the pilot.

Speed for a night fighter could be lower than for a day fighter. There were very few night fighter vs night fighter combats in 1940-41-42. And most that did occur were by surprise.

The continued use of the Defiant as an operational night fighter (last victories in the Spring of 1942?) says more about a general lack of equipment than the Defiant's abilities. Wasting numbers of Havocs on the Turbinlite scheme and trying to keep it going until until 1943 says more about British stubbornness than their efficient use of available aircraft.

A point about perdator/prey speeds to bear in mind is that the prey may well be at a cruising speed to be able to reach the target and return. The predator, once it has a vector for the prey, can use maximum continuous speed so the differential is often greater than a comparison of maximum speeds would suggest.

I agree that the Defiant was a choice of nightfighter forced upon the RAF by circumstance. Ironically it put it in the position it was designed to meet: to bring down an unescorted bomber.

Was it a success? No but neither was it a failure. It was soon replaced by aeroplanes with more powerful armaments, longer loiter times, higher dash speeds and better radar but it does not seem to have done markedly worse than it's true contemporaries; all of whom made little impact upon night bombers, from the Luftwaffe over London to the Italians and French bombing Gibraltar to name but two circumstances.

The Defiant's success ( or lack of it) as a night fighter is also due to the rapidly changing conditions. For the vast majority of the 1940/41 winter night blitz the Defiants were not equipped with radar. Or at least the service squadron Defiants were not. By the time Defiants were being fitted with radar in large numbers the winter Blitz was well past and large numbers of Luftwaffe bombers had departed for the Eastern front, leaving a less than target rich environment. German operations scaled back considerably.

Germans dropped 36,844 tons of bombs on Britain in 1940, 21,858 tons in 1941 ( most in the first 5 months) and dropped to 3,260 tons in 1942, less than 1/10th the 1940 total.

yulzari said:

A point about perdator/prey speeds to bear in mind is that the prey may well be at a cruising speed to be able to reach the target and return. The predator, once it has a vector for the prey, can use maximum continuous speed so the differential is often greater than a comparison of maximum speeds would suggest.

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Absolutely. But that vector can only be achieved with airborne radar,a command and control system based on ground radar or a combination of both. None of this existed when the Defiants were originally "given a coat of black paint" as Shortround 6 accurately puts it.
Did they even get exhaust flame dampers or just a shield like Hurricanes?
Cheers
Steve

yulzari said:

I agree that the Defiant was a choice of nightfighter forced upon the RAF by circumstance. Ironically it put it in the position it was designed to meet: to bring down an unescorted bomber.

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I'm not sure that it wouldn't have become a night fighter even if it had been successful in daytime. The Hurricane became a night fighter even though it was successful in daylight operations.

When the Luftwaffe switched its strategy to night bombing, the whole picture changed. I think the discussion about the Defiant's daytime performance is a red herring, tbh.

VinceReeves said:

I'm not sure that it wouldn't have become a night fighter even if it had been successful in daytime. The Hurricane became a night fighter even though it was successful in daylight operations.

When the Luftwaffe switched its strategy to night bombing, the whole picture changed. I think the discussion about the Defiant's daytime performance is a red herring, tbh.

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I agree,apart from the fishy bit.

It was a lack of daytime performance that led to talk of relegating (not my word) the Defiant to a night fighter role before it had been shown to be inadequate in the unforseen daytime fighting environment into which it was thrust. It's daytime and nightime performance are essentially the same. The performance of any aircraft in a given role can surely not be a red herring. Slow during the day equals slow at night

Cheers

Steve

stona said:

Slow during the day equals slow at night

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Slow is relative. The Beaufighter would have been slow for daylight interception.

Btw, if it was Dowding who was talking about nightfighting in terms of "relegation" it confirms why he lost his job.

VinceReeves said:

Slow is relative. The Beaufighter would have been slow for daylight interception.

Btw, if it was Dowding who was talking about nightfighting in terms of "relegation" it confirms why he lost his job.

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No,it was the Wing Commander Armaments whose name I can't decipher. I can't look him up at the moment.

Dowding pushed hard for a radar equipped night fighter. He also opposed moves by men far less qualified in the management of air defence (he and his system had after all had just won the BoB) to have aircraft flying around aimlessly over London in the hope that a suitable target would materialise. He gave good reasons for this. The toll taken on airframes and engines and also the wearying of flight crews which this kind of patrolling entailed with a negligible chance of success.He believed that asking ill or part trained RAF aircrews to carry out such night time operations would incurr more accidental casualties to the RAF than they could hope to inflict upon the Luftwaffe. A look at the appalling accident rate of the late war Luftwaffe night fighter arm would suggest that he had a point. He was not always politic in expressing his views and barely hid his disdain for men like Rear(later in this period Vice) Admiral Phillips when he expressed his opinion on how best to protect Britain's air space.
The technology for an effective night fighter was simply not there in late 1940,and that was not Dowding's fault. It was one of the things used against him in the moves to have him removed but was just one factor in a long running campaign and certainly didn't cost him his job per se.
Cheers
Steve