Boulton Paul Defiant

[Glider]

I think its fair to say that there was nothing wrong with the Defiants Turret, just that it was designed to carry one limiting its adaptability. There was no excuse on behalf of the RAF command over this waste of men and resources. The most successful two man fighter of all time, the The Bristol Fighter of WW1 didn't do all well until the pilots learnt to stop trying to position the plane for the rear gunner and fight it like a normal fighter. Leaving the rear gunner to keep the tail clear and take what oppertunities arose. By giving the Defiant no front guns they made it useless for day fighting.
Its also worth remembering that Wellingtons, Lancasters and Halifax's were designed with a ventral turret, they just didn't work.

 

[HealzDevo]

Ok, fascinating look at history. What do you think about that fact that if the Defiant had been shifted to Night-Fighting role earlier it might have prevented more of the earlier German night raids on England? Would it have been successful at that or just as bad...

 

[Glider]

Nightfighting depends on Radar. They may have shot down one or two more German bombers but they still would have been stumbling around in the dark and had little impact overall.

 

[bomber]

I agree with Glider on this...

I expect the losses due to ground crashes would have outweighed the numbers of enemy shot down.....

reading up on it nightflying scared the pants off of pilots.

Simon

 

[The Basket]

One pilot who flew the Defiant said it was a good flying machine. But the turret idea was its downfall. He said that it could have made a fine ground attack platform without the turret but bad showing in the BoB ruined its reputation.

Also the Wilde Sau missions didn't have airborne radar so it is possible to be effective without.

 

[Glider]

I doubt that Wilde Sau would have really worked over the UK in 1940. To really work well the ground needed to be a sea of flame for the bombers to be seen against and a large number of bombers needed to be in the sky at more or less the same time.
German Bomber raids were a lot smaller than the British night raids normally in the dozens, not hundreds and were spread out over a long time.

 

[Marcel]

The wilde Sau was also not so very effective, only succeeded a few times, but most of the time it was a failure. Just a stopgap when the germans needed all to stem the tide.

 

[The Basket]

TBH I do have a soft spot for the Defiant. Not a bad aircraft but never made the team. The concept was outdated and never worked in battle. But the turretless was faster than a Hurricane and may have made a grand attacker in the North African desert.

Maybe there were better places for a RR Merlin.

 

[Downwind.Maddl-Land]

The Defiant wasn't a bad aeroplane; it was just misused, as there were no alternatives and desperate times called for desperate measures. If, as it was intended, it had been used in conjunction with other fighters (eg Hurricanes and Spitfires) it could be extremely effective.

The Defiant's 'hour of glory' came on 29 May 1940, when it was employed correctly. Twelve Defiants of 264 Sqn headed for Dunkirk at relatively low altitude looking for bombers while Nos 56, 151 213 Sqns of Hurricanes flew top cover. The formation was attacked by Bf 109s and 6 109s penetrated to the Defiants where 3 of them were shot down by the Defiants and a further 1 damaged; 1 Defiant was damaged and the gunner bailed out, but was lost in the English Channel. The aircraft did make it back to England, the pilot safe. 264 pressed on to the beaches and attacked He 111s. During this meleé a formation of Ju 87s and Bf 110s was spotted and the 110s attacked the Defiants with little effect. During this battle I understand 7 x 110s were claimed, as well as 4 more 109s and a Ju 87.

The same afternoon 264 returned to Dunkirk, again escorted by Hurricanes and, again, were intercepted by 109s. A 'bitter battle' ensued between the Hurricanes and the 109s but the Hurricanes kept the 109s off the Defiants, allowing the Defiants to attack a large formation of Ju 87s that were striking the beaches. A one sided running battle developed just above the waves as the Defiants did what they were designed for - attacking bombers. It was a Turkey Shoot for the Defiants; one team (Plt Off Cooke Plt Off Kay) claimed 5 Ju 87s by engaging the bombers from underneath and firing into the unprotected bellies of the Stukas – a foretaste of Sträge Musik? 264 then 'went' for a formation of Ju 88s. At the end of the day 264 claimed: 8 x 109s, 9 x 110s, 19 x Ju 87s, 1 x Ju 88 and another 3 'probables'.

This record (OK, the claims were over the top, but that always happens) shows what the Defiant could achieve when employed correctly with top cover to ward off the escorting fighters and aggressive leadership; the OC 264 (Sqn Ldr Hunter) was revered by his crews evidently.

The above shows that if ever an aircraft should have been employed in Bader's Big Wing, it was the Defiant – although the reaction of 'Himself' is best left to the imagination! If 264 and 141 had been part of the Duxford wing with 3 other Hurricane/Spitfire Sqns they could have made a positive contribution to the Battle, without becoming the sacrificial lambs they were, when used in isolation within 11 Gp. It just goes to show that there are Horses for Courses. Acknowledgements to Alec Brew, author of 'The Defiant File'.

 

[trackend]

Never knew that, good post DW.

 

[Downwind.Maddl-Land]

Sqn Ldr Hunter also flew in mock combat against a Spitfire of 65 Sqn flown by one Flg Off Tuck! Hunter flew on a course from Northolt to White Waltham (I lived at both those places during my Service career!) and Tuck attacked when and how he liked. Hunter went into a steep turn followed by the Spitfire. In an engagement that lasted 10 minutes, the Defiant gunner expended all his cine film, but Tuck expended none as he could not bring his sights to bear. He was often able to turn inside the Defiant but this only enabled the gunner to fire on him across the arc. On one occasion Hunter managed to get on the tail of the Spitfire, slightly below so that the gunner could fire forward and upwards. This engagement showed that a well-flown Defiant, which circled when attacked by a single seat fighter could adequately defend itself, provided its speed did not drop below 160 mph, which usually involved a spiral dive. Again, acknowledgements to Alec Brew, author of 'The Defiant File'.

 

[Wildcat]

Very interesting. Were these trials done before or after the Defiants were withdrawn from frontline service?

 

[Downwind.Maddl-Land]

Before; the inference is they were conducted during operational Work Up, while tatics were being developed for the new fighter.

 

[TenGunTerror]

Yeah the Defiant's gun could be locked forward but I previously read that the gunners didn't like doing it because they couldn't protect the rear! It is very confusing when a plane is head on and you're worried about the tail...

 

[nuuumannn]

Since the Daffy has arisen as a subject again, I thought I'd resurrect this thread rather than start a new one.

The fundamental problem facing the Defiant in the Battle of Britain was that there not very many of them. Only one squadron was ever in combat at any time and only two squadrons used the type as a day fighter; of those, 141 had one disastrous combat, which has been covered elsewhere, so it was kept out of the fight for further day fighter use.

During the battle, the highest number lost in one combat was six, which isn't that high, but when you consider that only nine were airborne at that time, it's a big percentage. Six aircraft lost of a squadron of 12 is fifty percent of squadron strength gone, which on paper is unsustainable. By comparison that figure was often reached and exceeded by Spitfire and Hurricane - and indeed in Luftwaffe squadrons. If there were more Defiant units, the losses suffered - as small in number as they actually were - would not have seemed so excessive compared to the number of aircraft in action.

Another aspect worth considering was the number of combats the Defiant took part in. Not as many as might be thought - they certainly weren't being sent up every day.

We'll go into this at a later time... gotta go feed the chickens...

 

[nuuumannn]

Chooks are fed!

Total number of days on which the Defiant engaged in combat between May 1940 and end of August was eight, although on a couple of these days 264 Sqn took off and landed to re-arm and refuel before getting airborne again. By the end of May 264 Sqn had flown 174 sorties and claimed a total of 65 enemy aircraft for the loss of 14 Defiants. Obviously the e/a claims are exaggerated due to the excitement of the time.

A total of 32 Defiants were shot down on day operations. During the Battle of Britain proper the Defiant entered into four engagements with the enemy and 18 aircraft were lost; six in one engagement from 141 Sqn on the 19th July (a seventh crashed on return after being shot up but was subsequently repaired). That leaves 264 Sqn losing 11 aircraft in three combats.

(These figures from The Defiant File by Alec Brew)

As can be seen, these are not high figures and even bearing in mind the production output of Boulton Paul were not unsustaineable losses.

 

[nuuumannn]

Regarding the Defiant's turret, it was an excellent piece of machinery. Designed in France by an engineer called de Boysson it was first built by Societé d' Application des Machines Matrices (SAMM), who granted BP a licence to produce it. For its time the SAMM turret was considerably advanced. Powered by the aircraft's electrical system via slip rings fitted in the base of the rotating section of the turret, its movement was actuated by a self contained hydraulic pump. Equipped with 600 rounds per gun, its most novel feature was its single-handed operation via a single joystick. Extensively applied in British bombers during and after the war, all Boulton Paul's turrets were based on the technology of the original SAMM electro-hydraulic unit. Although heavier and more complex to maintain than their contemporaries, the BP turrets were more sophisticated and easier to manipulate, however. Being self contained, they could continue operating even if essential services aboard the bomber had been disabled, which proved to be a big advantage in combat.

In service the turret's biggest drawback was access, which was done by rotating it 90º. Bailing out was via a door in the bottom of the rear fuselage, which the gunner had to wriggle himself into from the turret, a feat almost impossible for any normal sized human being. Consequently, in action Defiant gunners got themselves out the same way as they got in.

Although the gun turret could fire forward under control of the pilot via a push-button trigger on his spade-grip joystick, the guns' minimum elevation pointing forward was 19° and he did not have a gun sight.

 

[Glider]

Chooks are fed!

Total number of days on which the Defiant engaged in combat between May 1940 and end of August was eight, although on a couple of these days 264 Sqn took off and landed to re-arm and refuel before getting airborne again. By the end of May 264 Sqn had flown 174 sorties and claimed a total of 65 enemy aircraft for the loss of 14 Defiants. Obviously the e/a claims are exaggerated due to the excitement of the time.

A total of 32 Defiants were shot down on day operations. During the Battle of Britain proper the Defiant entered into four engagements with the enemy and 18 aircraft were lost; six in one engagement from 141 Sqn on the 19th July (a seventh crashed on return after being shot up but was subsequently repaired). That leaves 264 Sqn losing 11 aircraft in three combats.

(These figures from The Defiant File by Alec Brew)

As can be seen, these are not high figures and even bearing in mind the production output of Boulton Paul were not unsustaineable losses.

I think we are going to have to agree to disagree as to the high losses. 174 sorties and 14 losses is a loss rate of 8% and note that those are sorties, presuamably a number of those did not involve combat which sends the loss ratio through the roof.

Regarding its use as a fighter, fighters are there to attack the enemy. Having one tactic that might work when defending yourself doesn't help you attack anything.

The Defiant was slow, had a poor climb and had to rely on a defending bomber being very docile. At the end of 1939 I get the feeling that Dowding was very unsure as to the success that could be expected.

The CO of 264 was very reluctant to follow the official line, that the combat trials were not considered by the RAF to be representative and doubts were being raised in Jan 1940 as to how well it would do in day fighting. In view of what happened I can only say that the doubters were right to doubt

 

[yulzari]

A part of the turret fighter concept that is usually overlooked is that of 'no deflection' shooting whereby the sight and the line of fire coincide (Google 'no deflection'). The reason for the Defiant turret being able to lock it's guns forward was to be that the pilot could use them in this mode (in conjunction with a suitable sight and training). Hence the pilot's firing button.

Sadly the concept got lost in the RAF works and pilot's were never advised nor trained in it. The only squadron to (on the commander's initiative) devise, experiment and practice unique procedures to maximise Defiant offensive and defensive manoeuvres was far more successful but the advice fell on deaf ears.

In effect the Defiant was possessed of both a 4 gun powered turret that could outgun a contemporary bomber from any direction and in concert with other Defiants, together with a fixed forward firing 4 gun battery. Hence there was no need to allow for wing guns. Boulton Paul were well aware of the weakness in a 4 x .303 battery and were working on a 20mm turret that would allow Defiants to lob 20mm HE shells at bombers from outside their defensive range.

Hindsight tells us that the Defiant was a good answer but to the wrong question. However, a well trained crew, practiced in the full use of the aeroplane, was able to both defend itself and attack contemporary bombers; but few were ever so fortunate and all lacked the vital pilot gunsight. With the no deflection gunsight and proper training I suspect we might have been talking of the Defiant as the 'Bristol Fighter of the Battle of Britain'.

The subject of pilot shortage has been touched on above and was genuine. However, there was a need for pilots to be available to attack invasion barges (and Bomber Command gets too little credit for their channel port bombing) and to attack the invasion itself. The crews of target tugs, training instructors, pilot trained ground staff, army cooperations, communication flights etc. were only allowed to be dribbled into Fighter Command so that an invasion could be met with hundreds of bombing aeroplanes. Even if they might range from Battles and Blenheims through Harts, Wallaces, Henleys, Oxfords to Tiger Moths to give a very uncomprehensive list. I have known an ex-target tug pilot who, with his colleagues, was consistently refused permission to transfer to Fighter Command as his Wallace would be needed as a bomber should there be a German invasion.

Commonwealth pilot training was the real jewel in the crown of the air war. Other than in the first year of the war, aircrew training generally exceeded demand and training programmes were scarcely ever reduced and were generally made to increasingly higher standards. The late war shortfall was in infantry and tank crews due to WW1 type losses in the fighting from Normandy to Germany through northern France, Belgium and the Netherlands. By 1945 the losses meant that even excess aircrew in training were reroled into infantry and serious consideration was given to reducing coal output to release conscripted miners for infantry training. After 6 years of war Britain was simply running out of young men to fill regiments in NW Europe, Italy, Greece and Burma whilst maintaining a Navy across 3 oceans and the Arctic, never mind a huge air force.

In contrast we can see the quality of aircrew declining for the German and Japanese air forces as they devoted too little resources to training so the fighting equipment they made was wasted on the new aircrew and one can see it was the experienced ones who were the only effectives users.

 

[nuuumannn]

The CO of 264 was very reluctant to follow the official line, that the combat trials were not considered by the RAF to be representative and doubts were being raised in Jan 1940 as to how well it would do in day fighting. In view of what happened I can only say that the doubters were right to doubt.

Yep, you are absolutely right, they were right to doubt; the thing is, the Defiant was not designed for the purpose of attacking single seat fighters, but it was employed in that role. Hence my comment about misappropriation of resources in another thread. Yet, despite a couple of bad days (264 Sqn suffered six shot down on one day too, but no lesson was learned) the Defiant continued to be used in a role it was not designed for. Clearly as these documents show, there was doubt about its speed in the face of the enemy, yet apart from Sqn Ldr Hunter's efforts, nothing was done officially to change its tactical use in the battle. This is not the fault of the aircraft, as obvious as that statement is.

Bearing this in mind, the Defiant did not do anywhere near as badly as is always assumed. Your statement of "loss rates through the roof" is a bit of an exaggeration considering only 14 aircraft were lost in combat in those 174 sorties, regardless if they were all combat sorties or not. Read my earlier post; on papr it looks worse than actual numbers suggest, but 14 lost in a month is not comparitively high losses at that time. As a percentage of a single squadron, yep - looks real bad on paper.

Yes, I agree with you that the Defiant should not have been used in the roles it was, convoy escort, standing patrols, yet, throughout the time it was - that is the fault of Fighter Command for ignoring the signs i.e. your documents - especially the last line of the January one! My second point is that losses of Defiants were not as high numerically as assumed by comparison to other types and the type fared better than you give it credit for. Yes it was slower than single seat fighters, but no more vulnerable than any other fighter if the tactics 264 Sqn employed were used. Actual combat proves that.

Regarding Sqn Ldr Hunter's reluctance to follow the official line - why would he? the tactics Defiant crews were trained to use against bombers clearly wouldn't work against fighters! His actions saved the lives of his squadron mates! Almost all RAF pre-war tactics were found wanting once the shooting started - squadrons were left to their own devices to adopt tactics based on their experiences, this is why Sailor Malan put out his Ten Rules of Air Fighting; this wasn't an edict from up above, this was a commander concerned about the high losses his troops were suffering. Again, the reason why RAF units adopted the Finger Four formation was because combat experience that proved that the Vic formation was unwieldy. This is also why indidivual airmen synchronised their guns to meet at a much closer range than what was officially specified and fitted armour plating behind their seats. These didn't come from official sources.

There was no substitute for experience; Hunter was smart to trial these tactics - wouldn't you if you were in his position? They were employed in combat and proved successful - no better endorsement than that. 141 Sqn's CO refused to listen to Hunter when they met after the squadron was declared operational in May 1940 and it cost him and his squadron dearly.

As for that January document, as you are well aware, interception speeds need to be high, but combat descends and speed bleeds off - the Defiant proved on a number of occasions that it could successfully intercept and destroy unescorted bombers by day - the role it was designed for. On 27 May 1940 264 Sqn encountered a formation of 12 He 111s and shot down three of them and damaged a fourth without loss to the Defiants.

Interesting documents though Glider, thanks for sharing. Since I am in New Zealand it's kind of hard for me to gain access to material about the Defiant from official sources. I am keen to get hold of documents that outline when and why (yes, I know why, but offically) the Daffy squadrons were withdrawn from day ops.