Westland Whirlwind revisited

[Schweik]

I think you are a bit at right angles to what I was trying to point out. I'll try to break it down in a more logical way than my past scattered posts.

1. I cited the Ki-46 as an example of what you could do with a Whirlwind, as a proof of concept of the small military aircraft in the sense that it was a successful design. In the case specifically of a successful small twin-engined warplane as a way to make a fast mover (by the standards of the early war) with limited engine power that was available at that time.
2. The Ki-46, to be a useful recon plane for Japanese purposes in the Pacific, was made a very long ranged bird. This was something you saw as a flaw and described as a 'flying gas tank' but any truly long range aircraft is going to be a bit of that.
3. I'm sure there would be a way to make a Whirlwind into a long range aircraft but I suspect it would have been more useful and easier to get into action as a low altitude, short to medium ranged recon aircraft. Yes they had a Mustang I but those weren't the long range fighters of a later model Mustang, they also as you know had a serious problem with their ailerons which made them not particularly good at dogfighting. Hence their limited use.
4. Any successful mission role, IMO, would have warranted making and further developing both Whirlwind and the peregrine engine. If for no other reason than the (already repeatedly pointed out) waste of resources for aircraft types that either had no mission at all or had a mission that required a small percentage of the numbers being produced. Tactical Recon was a major problem for the Desert Air Force and a capable recon plane would have been very helpful.
5. The Whirlwind probably had at least two viable missions - dive bomber and short or medium range Tactical recon such as Tac-R missions, and probably a third as some kind of low altitude fighter.
6. You have a point about good planes like later model Spitfires and Mosquitos (and maybe Allison Mustangs?) being kept in Britain, but a cheaper aircraft like a Whirlwind would be a good one to send out to the secondary and tertiary Theaters. The mosquito by contrast proved problematic in Tropical environments due partly to the effects of humidity on it's laminated wood construction.

As for what made the Ki-46 "unmaneuverable", that is an unrelated issue to my point but I'm willing to go there. I have seen that comment but don't know what they mean by it precisely. It was obviously a low drag design so that may mean low drag wing shape which sometimes translates to lower lift. It may have just come down to reducing the fuel load or changing how the control surfaces were set up (as turned out to be the case with the P-51, a relatively minor change to the aileron seemed to fix it's maneuverability problems). Maybe bigger ailerons for roll or some maneuvering flaps for turn. I'd have to know more about what precisely was considered deficient. Wing loading doesn't look bad at all (32 lbs per square ft).

 

[stona]

The problem with point 1 is that it uses two engines. The MAP was not at all happy about that, or the cost, both monetary and in materiel, of the Whirlwaind.

The problem with point 2 is the Spitfire. Cotton's Heston Flight was set up soon after the outbreak of the war. It was initially planned to use Blenheim's but they soon proved unsuitable. The answer was the Spitfire. This was a reflection of an August 1939 memorandum sent to the Air Ministry by Maurice Longbottom who had been involved in clandestine flights over Libya to photograph Italian fortifications.

"...this type of reconnaissance must be done in such a manner as to avoid the enemy fighters and AA defences as completely as possible. The best method appears to be the use of a single small machine, relying solely on its speed, climb and ceiling to avoid detection."

He was right, hence the PR Spitfire. There was interest in a PR Whirlwind. Westland gave some rather over optimistic estimations of such an aircraft's performance. When the A&AEE concluded that the service ceiling of a PR version would be as low as 28,000 feet this killed it off. Sholto-Douglas was informed

"...It is therefore very disappointing indeed after what we had been told to learn that the Whirlwind has a ceiling of only 28,000 feet. I regret that this ceiling renders the aircraft unsuitable for the requirement and, in that event, the only thing to do is to renounce the 26 aircraft which I believe have been earmarked for this sort of work and to look around for something else..."

Nice try, but it was tried at the time, and rejected.

Point 3 is moot because there was zero interest in doing any such thing.

Similarly point 4 because about a million posts ago I explained when and why the Peregrine engine was deleted. There was never any chance of it being developed.

Point 5 is largely what the Whirlwind did, but there was never a need for more of them. Eventually the Typhoon would do more, with one engine.

Point 6. The Whirlwind was not cheap. It was in fact very expensive, see my response to point 1.

 

[Schweik]

The problem with point 1 is that it uses two engines. The MAP was not at all happy about that, or the cost, both monetary and in materiel, of the Whirlwaind.

There is more to expense than production cost. What's cheaper, two Hurricanes that get shot down on their first mission, or a Whirlwind that can last ten or twenty missions or more? (in both cases assuming the high loss rate of some kind of recon flights).

More to the point, a Henley or any of the other list of wasteful designs still being produced (and given valuable engines) had little to any use at all for any kind of missions... you already had plenty of old obsolete planes to use for target tugs.

The problem with point 2 is the Spitfire. Cotton's Heston Flight was set up soon after the outbreak of the war. It was initially planned to use Blenheim's but they soon proved unsuitable. The

Spitfire PR was good, but as you noted, it was designed for that high altitude role, and many were proverbial "flying gas tanks" to use Shortrounds term. A low altitude fighting recon plane was also needed, in part due to the limitations of camera technology as well as the exigencies of weather. They did have some Spit Mk IV PR D types in the MTO I know, but they still used those poor Hurricane pilots for the TacR missions.

I already stipulated that the Whirlwind was going to be easier to make into a low alt recon plane than a high altitude - the high altitude role was reference to how the Ki-46 was historically used, which was necessary for a couple of different reasons in the Pacific.

Nice try, but it was tried at the time, and rejected.

Oh it still could have been done, but it would have required a two stage or at least two speed engine, which would have meant a longer lasting development cycle for the Whirlwind. Something for the MK II or MK III Whirlwind.

Point 3 is moot because there was zero interest in doing any such thing.

There absolutely was interest which is why they used the Allison engined Mustang for so long, and why so many men died flying Hurricanes and Tomahawks and P-38s and Spitfires on recon missions. With two engines, and good single-engine performance, Whirlwind would have been good for the hairy tactical environment of the MTO and (with some increased fuel capacity and / or drop tanks) in longer flights over the Pacific or North / Baltic Sea.

Similarly point 4 because about a million posts ago I explained when and why the Peregrine engine was deleted. There was never any chance of it being developed.

Well on the one hand we know they cancelled the Peregrine so in that sense you are right. What we are debating was whether that decision was correct and also (secondarily) whether another engine could have been used on the Whirlwind. It simply isn't the case that the Peregrine "never had any chance of being developed" - it certainly could have been if the War ministry told RR to do so. Either through licensing or by using some of the capacity that was being diverted to Merlin engines for useless designs. The issue was that they couldn't see the reason to do so. We have the benefit of hindsight hence the entire point of the thread.

Point 5 is largely what the Whirlwind did, but there was never a need for more of them. Eventually the Typhoon would do more, with one engine.

There was a looong gap between the Whirlwinds first combat flight and the Typhoon actually becoming an effective and reliable combat aircraft. This is one of the points of developing the Whirlwind and one of the best reasons that the statement "there was never any need for more of them" is incorrect. What would have been better for England, 2,000 Whirlwinds chasing Stukas and Fw 190s around the coasts and the Channel, dive bombing ships and intruding over France, or the equivalent number of Defiants, Henleys, Lysanders, Bothas, Skuas, and Albacores? Which of the latter could have any hope of intercepting a Fw 190? Of surviving combat with a Bf 109? Of shooting down Bf 110s? Which would be a more efficient killer of Stukas and Ju 88s?

Point 6. The Whirlwind was not cheap. It was in fact very expensive, see my response to point 1.

That may be a good point. However further development may have improved that issue as well, I am not qualified to say.

 

[Schweik]

The need for an accurate dive bomber that had a reasonable chance of surviving an encounter with a first-line enemy fighter was very pressing, both in the Pacific and the MTO, and probably the CBI as well. The A-36 (Mustang) proved partly capable of that role (eventually) in the MTO and CBI, but was ultimately retired from it because it couldn't really take the strain of dive bombing pullouts.

The A-24 (Dauntless / Banshee) proved not really ready for Bf 109s in the MTO (basically not fast enough), same for the Albacore needless to say. Fighters could carry bombs but they bombed targets at a shallower angle than what was reported with the Whirlwind, and that means less accuracy. The Germans got a lot of mileage out of of their Ju 88 in the dive-bomber role and the Whirlwind could have been equivalent in many respects, and probably better against enemy fighters.

In the Pacific, until large numbers of Beaufighters arrived, I think the Whirlwind definitely had a useful potential niche.

 

[Shortround6]

I agree with most everything you posted.

Except

Point 5 is largely what the Whirlwind did, but there was never a need for more of them. Eventually the Typhoon would do more, with one engine.

It might be better said that the Typhoon did it with one propeller

That Sabre engine might have been considerably more expensive than 2 Peregrines (assuming the Peregrines were built in quantity)

The Typhoons reputation as fighter bomber was also achieved (mostly) using the Sabre IIA and II B engines and using the 4 bladed prop.

An early (1942/early 1943) Typhoon may not have been a much better fighter bomber than the Whirlwind but it was already too late for the Whirlwind by several years.

 

[Schweik]

Why is it too late for the Whirlwind? Weren't they still (amazingly) flying missions in 42-43? Imagine if you had some MK II and III ones available before that Sabre IIA with the 4 bladed prop was ready to go...

 

[stona]

PR Spitfires were quite capable of doing low level PR work. I thought everyone had seen Tony Hill's images of the Bruneval site, taken from Spitfire R7044 on 5th December 1941, around about the time the Whirlwind was just supposedly becoming operational.

The Whirlwind was not fitted with bomb slips until October 1942. The first flight was made with racks fitted on the 21st. There were three operations in November. The decision to persevere with the Typhoon was taken in January 1943 (largely due to Beamont and 609 squadron's successes in France) and shortly after a dive bombing force was developed. 500lb bombs were released to the operational squadrons in early 1943, I'm not sure when the first operations were carried out. Maybe the gap between the Whirlibomber and the Bombphoon is not as large as you thought?

 

[wuzak]

Well on the one hand we know they cancelled the Peregrine so in that sense you are right. What we are debating was whether that decision was correct and also (secondarily) whether another engine could have been used on the Whirlwind. It simply isn't the case that the Peregrine "never had any chance of being developed" - it certainly could have been if the War ministry told RR to do so. Either through licensing or by using some of the capacity that was being diverted to Merlin engines for useless designs. The issue was that they couldn't see the reason to do so. We have the benefit of hindsight hence the entire point of the thread.

There are two issues here - development and production.

While production Merlins went into aircraft that were less than useful, the majority went into aircraft that were essential. Cancelling "useless" aircraft would free up Merlins for other use, but not production capacity for the engines. To build the Peregrine would require a new factory, or a changeover from a different engine.

Development is the bigger problem.

While Rolls-Royce pushed very hard on the development of the Merlin they didn't have the resources to develop too much more. Developing the Peregrine would rob resources from other engines - the Merlin or the Griffon.

The Exe was cancelled around the same time as the Peregrine.
The Vulture development was paused during BoB, then cancelled in 1941.
Crecy development was continued, but essentially with a skeleton crew, hence its slow development.

So which would you sacrifice to pursue the Peregrine - the Merlin or the Griffon?

 

[Schweik]

Cancel the vulture early that should free up enough to give you a few more Peregrines.

The point about the Henleys etc. was that they had some slack production of merlins if they could afford to put them on dedicated target tugs...

 

[wuzak]

Cancel the vulture early that should free up enough to give you a few more Peregrines.

Why would it? They are almost completely 2 different engines.

The point about the Henleys etc. was that they had some slack production of merlins if they could afford to put them on dedicated target tugs...

Sure the Merlins could have been used for more worthy aircraft, but that has no bearing on the possibility of making more Peregrines.

 

[Shortround6]

The Whirlwind, like a few other small twins, had some definite limitations.

A lot of people keep over estimating the Whirlwinds size. It was not a large airplane compared to many other western fighters, it had a smaller wing than Hurricane let alone a Typhoon (Or P-47 or F6F) and in fact only had 8 sq ft more than a normal Spitfire. There is only so much fuel you can put in it, it was never going to be a long range escort fighter (or even medium range one). but then neither was the Typhoon (154IMP gallons internal).

The Whirlwind was not going to be a long range recon plane, You could rip the guns out of the nose, you still weren't going to get enough fuel in the plane.
It was never going to be a two seater (night fighter or???) except maybe a trainer, (rip out 2 or more guns add forward cockpit?

The ability of the Whirlwind to get home on one engine is part illusion, some did, some did not.
This is not the fault of either the engine/s or the airframe but rather penny pinching that kept dual generators and duel hydraulic pumps from being fitted. However this flaw was rather wide spread and affected quite a number of multi engine planes. The early Halifax may have been one of the worst with 3 electric generators with no crossover, each generator ran all the electric in one part of the plane. If you lost an engine which gun turrets and other accessories still worked depended on which engine was lost.
On the Whirlwind the propellers could not be feathered, just put into coarse pitch and a brake applied to keep the prop from turning.
You also could not transfer fuel from one side of the airplane to the other. When you lost an engine the only fuel to get home with was the fuel in the wing next to the running engine. the fuel in the other wing was just so much dead weight.
This could have been a easy fix on a later batch of aircraft.

There were a number of things that could have done to improve the Whirlwind in a MK II (or III) version that do not require new or different engines. ANd the engines themselves did not need a lot of development. Just get them up to Merlin 45 standards and pick what altitude you want to fly and fit appropriate gear ratio and/or impeller. Do the development on the Merlin and let the improvements trickle down. Ground pounder Whirlwind? Peregrine equivalent to a Merlin 30 (or Merlin 45 with cropped impeller) more altitude? Peregrine version of Merlin 45

The Whirlybomber only came into existence at a time when the only other active fighter bombers in England were two squadrons of Hurricanes. That was a lot of target area (NW Europe) for two squadrons of anything so fitting bomb racks to Whirlwinds doubled the number of fighter bomber squadrons crossing the channel at the time, rather pathetic but there you are.

Without a 2nd or third use for the Peregrine I am afraid it's days were numbered ( would have made a nice tank engine without the supercharger to replace the Liberty as I have mentioned a few times before) Using it as a crash boat engine is stretching things but possible (it is too small for a MTB engine) but actual improvement over the Sea LIon may be small.

 

[tomo pauk]

The Whirlwind, like a few other small twins, had some definite limitations.

A lot of people keep over estimating the Whirlwinds size. It was not a large airplane compared to many other western fighters, it had a smaller wing than Hurricane let alone a Typhoon (Or P-47 or F6F) and in fact only had 8 sq ft more than a normal Spitfire. There is only so much fuel you can put in it, it was never going to be a long range escort fighter (or even medium range one). but then neither was the Typhoon (154IMP gallons internal).

The Whirlwind was not going to be a long range recon plane, You could rip the guns out of the nose, you still weren't going to get enough fuel in the plane.

The most important reason to why Typhon nor Whirlwind were not long-range escort fighters was doctrine of the user at the time. Same goes for Hurricane, Spitfire and Tempest.

 

[Admiral Beez]

deleted

 

[Shortround6]

The most important reason to why Typhon nor Whirlwind were not long-range escort fighters was doctrine of the user at the time. Same goes for Hurricane, Spitfire and Tempest.

Everything is tied together. Part of the British "doctrine" in the late 30s was getting the planes out of and into small airfields,

From the Thread on the Meteor vs 262.

Performance: The maximum speed at 30,000ft shall not be less than 430mph. When taking off from a grass surface with full fuel and military load the aircraft shall be capable of crossing a 50ft screen within a distance of 600 yards in stillair. On landing the aircraft should come to rest in not more than 700 yards, with full fuel and military load."

bolding by me.

If in 1940 this was the requirement for a jet fighter one can imagine the reception a piston engine fighter would have gotten in 1938 if the maker had told the Air MInistry, hey it's got great range, it can fly 1000 miles but it needs 800yds to clear the 50ft screen on take-off" Just build bigger airfields to accept the plane.
BTW a P-40E needed 750 yds to take-off from grass in zero wind to clear 50ft with no drop tank (8100lbs). At 8700lbs it needed just over 900 yds.

By the time the jets flew this requirement was nonsense.

 

[Shortround6]

How does the Curtiss YA-14 compare? Was a single seat version considered?

Why don't you google it and tell us your conclusion?

 

[tomo pauk]

Everything is tied together. Part of the British "doctrine" in the late 30s was getting the planes out of and into small airfields,
...
If in 1940 this was the requirement for a jet fighter one can imagine the reception a piston engine fighter would have gotten in 1938 if the maker had told the Air MInistry, hey it's got great range, it can fly 1000 miles but it needs 800yds to clear the 50ft screen on take-off" Just build bigger airfields to accept the plane.

There is no need to make new & bigger airfields, LR fighter will use same airfield for take-off that Battle is to be using.

 

[Shortround6]

What makes you think the Battle used a large airfield?

422 sq ft of wing for a 10,800lb airplane means a wing loading of under 26lbs per sq ft.
that a thick, high lift airfoil may have done the job.

Lets remember that a MK I Blenheim Bomber at 12,500 lbs was supposed to have a take off run of 296 yds (not to 50ft?) and a landing run with brakes of 364yds. with a wing loading of about 26.6lbs. Landing speed was supposed to be 50mph? (figures from 1938 Jane's) could be a misprint I suppose? and/or landing speed was really stalling speed? some books from the 30s tend to interchange the terms.

Blenheim V was supposed to have a stalling speed of 70mph, wheels and flaps down, at 16,000lbs. per the pilots manual.

There is a reason the Whitley used an 1100sq ft wing on an under 24,000lb airplane (MK IV, the earlier Whitleys were lighter)
And the weird scheme of wanting to catapult launch the Manchester bomber (at least in the planing stages).
Not all British airfields were tiny but in the mid to late 30s there were not many large ones. Bombers were lucky to get two pitch props and the fixed pitch props on the early fighters just about crippled them.
Fortunately somebody figured that a fixed prop on a 1700-2000hp was not a good idea and the Typhoon series never got that handicap.

 

[stona]

The Whirlwind had many problems, but a long landing distance was not one of them, despite the need to maintain power to maintain rudder and elevator authority. The A&AEE reported in 1938 that the landing was 'not fast or excessively long' at 635 yards. I assume that is the landing distance (over that imaginary fence) which is therefore not dissimilar to the Hurricane.

Post 1935 RAF aerodromes were supposed to have a landing run of 1,100 yards, though not all did.

Whirlwinds operated from RAF Warmwell, in Dorset, a pre-war airfield originally considered suitable only for biplanes.

 

[tomo pauk]

What makes you think the Battle used a large airfield?

422 sq ft of wing for a 10,800lb airplane means a wing loading of under 26lbs per sq ft.
that a thick, high lift airfoil may have done the job.
Lets remember that a MK I Blenheim Bomber at 12,500 lbs was supposed to have a take off run of 296 yds (not to 50ft?) and a landing run with brakes of 364yds. with a wing loading of about 26.6lbs. Landing speed was supposed to be 50mph? (figures from 1938 Jane's) could be a misprint I suppose? and/or landing speed was really stalling speed? some books from the 30s tend to interchange the terms.

Blenheim V was supposed to have a stalling speed of 70mph, wheels and flaps down, at 16,000lbs. per the pilots manual.

There is a reason the Whitley used an 1100sq ft wing on an under 24,000lb airplane (MK IV, the earlier Whitleys were lighter)
And the weird scheme of wanting to catapult launch the Manchester bomber (at least in the planing stages).
Not all British airfields were tiny but in the mid to late 30s there were not many large ones. Bombers were lucky to get two pitch props and the fixed pitch props on the early fighters just about crippled them.
Fortunately somebody figured that a fixed prop on a 1700-2000hp was not a good idea and the Typhoon series never got that handicap.

I've never said that Battle used large airfields.
Hurricane was renown for thick airfoil and low wing loading every bit as Battle or Blenheim.
The Hurricane prototype (K-5083, fixed-pitch prop) needed 265 yards for take off @5672 lbs. Landing speed was under 60 mph. At 6040 lbs (a more realistic service-worthy example) needed 370 yds.
Later, Hurricane I weighting 6363 lbs and fitted with 2-pitch prop needed 280 yds, or 240 yds with Rotol prop and 6316 lbs (280 yds with flaps at 20 deg and 6700 lbs).
LR hurricane will need drop tanks (say, 2 x 45 imp gals) and extra fuel internally (20 imp gals?) 110 imp gals x 7.2 lbs/gal= 792 lbs; there is some weight for plumbing and tanks themselves - another 100 lbs? So we have LR Hurricane at 7000-7500 lbs. Wing loading between 27 and 29 lbs/sq ft.
If we add another 100 yds for the LR Hurricane take-off distance, there is still no need for big aerodromes.

P-40 can't compete if we want low wing loading - at 8100 (P-40E clean) it is 34.3 lbs/sq ft. British fighters that mattered early on (Hurricane, Spitfire) were much better in that regard.

Blenheim I needed 700 yds to clear 50 ft obstacle (at max weight of 12500 lbs). Hurricane I needed between 420 and 580, depending on weight and prop type.

 

[Admiral Beez]

The Whirlwind had many problems, but a long landing distance was not one of them,

Here's one landing on a grass strip. Doesn't seem overly long too me.