Westland Whirlwind revisited

[Shortround6]

The supercharger from the Merlin 45 should've also worked, resulting at power vs. altitude not far away from Merlin III?

Critical (FTH) height for the Peregrine was supposed to be 15,000ft. Only 1250 ft less than the Merlin III. Not as good RAM? Exhaust thrust not developed as well (poor design of manifold and duct?)

Superchargers (centrifugal) have 3 different aspects of performance.
1. airflow in pounds (or KG ) per minute
2. pressure ratio. Pressure of out going air vs incoming air.
3. efficiency. How much power it takes to compress the needed volume or weight of air to the desired pressure.

You can only trade a bit of air flow for pressure before efficiency goes to pot (gets bad) and since even good superchargers only used around 70-75% of the power going to the supercharger driveshaft to actually compress the air, the remaining % of power simply heated the air to no purpose, using oversized superchargers is not going to get you much in the way of improved altitude performance.
It can also totally screw up cruise power settings as these superchargers have a minimum airflow below which they surge or stall repeatedly in very short time intervals causing rumbling in the intake duct/s and other problems.

Using a Merlin 45 style supercharger may get you what you want. Trouble with the Whirlwind is just how tight is it? The early Merlin engines used superchargers with the inlet offset a bit from the axis of the impeller and used a rather tight bend from the carb to the impeller. Part of the carb was actually part of the supercharger housing. On the Merlin XX/45 the carb was separate and there was an elbow to turn the airflow the 90 degrees from the carb to the supercharger axis. However this arrangement took several inches more room. Peregrine may (or may not?) have had a good inlet to begin with?

Peregrine00-1.jpg Photo by Secudus | Photobucket

I don't know how much room a 2 speed drive takes (some companies two speed drives took no extra length).

It might have been possible to get a two speed drive and a comparable supercharger to the one used on Merlin XX/45 but that might be the limit for available space without a lot of rework (and even that might require some.)

It also requires a bit of work to 'scale' the supercharger and build the new parts.

 

[Shortround6]

Channel Dash


No. 137 Squadron's worst losses were to be on 12 February 1942 during the Channel Dash, when they were sent to escort five British destroyers, unaware of the escaping German warships Scharnhorst and Gneisenau. Four Whirlwinds took off at 13:10 hours, and soon sighted warships through the clouds about 20 miles from the Belgian coast. They descended to investigate and were immediately jumped by about 20 Bf 109s of Jagdgeschwader 2. The Whirlwinds shot at anything they got in their sights, but the battle was against odds. While this was going on, at 13:40 two additional Whirlwinds were sent up to relieve the first four, two more Whirlwinds took off at 14:25. Four of the eight Whirlwinds failed to return.

And that describes all too many of the Whirlwinds missions. 2/4 Whirlwinds (often used as a "strike" section/element tasked with shipping/ground attack) escorted or accompanied by Spitfires for both flak suppression and fighter escort, sometimes planes from 3 squadrons were used totaling around 20 planes but only 4 Whirlwinds.

 

[rogerwilko]

Any aircraft being jumped is going to suffer?

 

[tomo pauk]

I'd say so.

Channel Dash...

Thanks for that, Michael.

Critical (FTH) height for the Peregrine was supposed to be 15,000ft. Only 1250 ft less than the Merlin III. Not as good RAM? Exhaust thrust not developed as well (poor design of manifold and duct?)

AT 15000 ft, the Peregrine's S/C was making +6.75 psi of manifold boost, vs. +6.25 psi @ 16250 ft for the Merlin III. At that altitude, the Peregrine's S/C will make close to that boost?

Superchargers (centrifugal) have 3 different aspects of performance.
1. airflow in pounds (or KG ) per minute
2. pressure ratio. Pressure of out going air vs incoming air.
3. efficiency. How much power it takes to compress the needed volume or weight of air to the desired pressure.

You can only trade a bit of air flow for pressure before efficiency goes to pot (gets bad) and since even good superchargers only used around 70-75% of the power going to the supercharger driveshaft to actually compress the air, the remaining % of power simply heated the air to no purpose, using oversized superchargers is not going to get you much in the way of improved altitude performance.
It can also totally screw up cruise power settings as these superchargers have a minimum airflow below which they surge or stall repeatedly in very short time intervals causing rumbling in the intake duct/s and other problems.

Thanks for that.
A supercharger is indeed a trade-off, and Peregrine have had a more than decent one, compared with other engines of the same era.

View attachment 282859

Using a Merlin 45 style supercharger may get you what you want. Trouble with the Whirlwind is just how tight is it? The early Merlin engines used superchargers with the inlet offset a bit from the axis of the impeller and used a rather tight bend from the carb to the impeller. Part of the carb was actually part of the supercharger housing. On the Merlin XX/45 the carb was separate and there was an elbow to turn the airflow the 90 degrees from the carb to the supercharger axis. However this arrangement took several inches more room. Peregrine may (or may not?) have had a good inlet to begin with?

Do we know the diameter of the Peregrine's S/C? Looking at the pictures, Peregrine also used the simple elbow, feeding the S/C with mixture from carb.

I don't know how much room a 2 speed drive takes (some companies two speed drives took no extra length).

It might have been possible to get a two speed drive and a comparable supercharger to the one used on Merlin XX/45 but that might be the limit for available space without a lot of rework (and even that might require some.)
It also requires a bit of work to 'scale' the supercharger and build the new parts.

Maybe installation of a 2-speed drive plus a new S/C would be too much of a hassle? Install a better/bigger S/C, rate the engine at +9 psi boost for take off (if/until it cannot handle full +12 psi) and performance goes up at all altitudes. The low compression ratio (6:1) should allow plenty of boost, and a more efficient S/C will heat the charge less.
Historically, max combat boost was +12 for the Peregrine?

 

[Aozora]

Two problems that haven't yet been mentioned were the poor fuel system of the Whirlwind; there was no cross-over between the fuel tanks so fuel couldn't be transferred from one tank to another in the event of an engine being stopped. Effectively, the lack of cross-over meant that the extra fuel became dead weight, instead of being useful.

A second problem was the 'Exactor' hydraulic engine controls, which were a constant pain in service. Redesigning these systems would have made for a better design.

Other thoughts; redesign the exhaust system to use ejector stubs; the design of the carburettor air intake was bad - correcting this, as Sir Stanley Hooker found out with the Merlin, would have improved the engine's power and efficiency. Allow the use of +12 lbs boost - this was experimented with during bench tests in March 1940 and produced 1,000 hp - for some reason this was not followed up, even though the engines were later cleared to use 100 Octane fuel.

 

[tomo pauk]

Here is a post by our nuuumannn:

This has been covered in another thread, but I can't be bothered looking, so I'll post from Rolls-Royce - The pursuit of excellence by Alec Harvey-Bailey and Michael Evans;

"Contrary to popular belief, the Peregrine was not unreliable. Its two main problems were rapidly tackled. Main engine joint failures were overcome by deleting the joint washers and using jointing compound, while bowstring failures of end cylinders holding down studs were cured by reducing anti-vibration collar clearances. Some of the stories of unreliability spring from difficulty in managing the operation of the radiator shutters during taxiing, take-off and initial climb. Westland had linked the radiator shutter operation with that of the aircraft flaps, so that there were times when the pilot had to use flaps to keep the radiator shutters open, when flaps were not needed in flight. In early operations a number of engines were overheated because the system was not fully understood, and evidence of this is in the pilot's notes, which were extensivelt amended."

 

[Edgar Brooks]

It is astonishing how the mere mention of the Whirlwind brings out the rose-coloured spectacles.
The Peregrine could only use 100 octane fuel in emergencies (whatever the Pilot's Notes say); to have modified it to full 100 octane capability would have meant many hours, and a new Mark of engine, so the possible use of the Merlin supercharger is academic.
The Peregrine could only be produced in the Derby Rolls-Royce factory, and R-R calculated that each one would have meant the loss of 2 Merlins, and delay of the entry of the Griffon.
The decision to stop building the Whirlwind was first made by Freeman in May 1940, and endorsed by Beaverbrook in October, long before any need for a dedicated ground-attack aircraft showed itself; Westland's output was turned over to Spitfires/Seafires in July 1941, and the RAF were delighted with the capability of the Hurricane in the desert, asking for as many IID as could be produced.
Westland could only produce 2 Whirlwinds per week, never enough to equip any force of any size, and certainly not enough to cover "wastage." They produced 2157 Spitfires Seafires in six years; to produce that many Whirlwinds would have taken 20+ years. Would you also be happy to leave Malta, the Desert Air Force, Australia, and the Navy with no means to defend themselves, apart from American aircraft?
Production capacity, in this country, was finite, due to the available numbers of factories, and always open to attack, as seen in the destruction of the Supermarine Eastleigh factory; new buildings, machine tools, jigs and workers couldn't be whistled up out of thin air, and a six-day working week was already normal.
Always forgotten, or ignored, is that the Air Ministry had already turned down Vickers' proposal for the Type 327 (two Merlins + 6 x 20mm cannon,) so the Whirlwind was always on a knife-edge.

 

[cimmex]

It is astonishing how the mere mention of the Whirlwind brings out the rose-coloured spectacles.
The Peregrine could only use 100 octane fuel in emergencies (whatever the Pilot's Notes say); to have modified it to full 100 octane capability would have meant many hours, and a new Mark of engine, so the possible use of the Merlin supercharger is academic.
The Peregrine could only be produced in the Derby Rolls-Royce factory, and R-R calculated that each one would have meant the loss of 2 Merlins, and delay of the entry of the Griffon.
The decision to stop building the Whirlwind was first made by Freeman in May 1940, and endorsed by Beaverbrook in October, long before any need for a dedicated ground-attack aircraft showed itself; Westland's output was turned over to Spitfires/Seafires in July 1941, and the RAF were delighted with the capability of the Hurricane in the desert, asking for as many IID as could be produced.
Westland could only produce 2 Whirlwinds per week, never enough to equip any force of any size, and certainly not enough to cover "wastage." They produced 2157 Spitfires Seafires in six years; to produce that many Whirlwinds would have taken 20+ years. Would you also be happy to leave Malta, the Desert Air Force, Australia, and the Navy with no means to defend themselves, apart from American aircraft?
Production capacity, in this country, was finite, due to the available numbers of factories, and always open to attack, as seen in the destruction of the Supermarine Eastleigh factory; new buildings, machine tools, jigs and workers couldn't be whistled up out of thin air, and a six-day working week was already normal.
Always forgotten, or ignored, is that the Air Ministry had already turned down Vickers' proposal for the Type 327 (two Merlins + 6 x 20mm cannon,) so the Whirlwind was always on a knife-edge.

Don't forget, whatif followers always have unlimited resources in their scenarios

 

[Shortround6]

Don't forget, whatif followers always have unlimited resources in their scenarios

True

However.

1 "The Peregrine could only use 100 octane fuel in emergencies (whatever the Pilot's Notes say); to have modified it to full 100 octane capability would have meant many hours, and a new Mark of engine, so the possible use of the Merlin supercharger is academic."
The Merlin only used the full 100 octane capability in emergencies for quite some time. As in anything over 6lbs of boost requiring notes in the log and maintenance procedures. It took how long for even the Merlin XX and Merlin 45 to be cleared for 12lbs or above?

2. "Westland could only produce 2 Whirlwinds per week, never enough to equip any force of any size, and certainly not enough to cover "wastage." They produced 2157 Spitfires Seafires in six years; to produce that many Whirlwinds would have taken 20+ years."
And while they were producing 2 Whirlwinds per week how many Lysanders were they building??? 5-7???
From AgustaWestland's site:
Spitfire Mk la, Vb Vc: 685 aircraft.
Seafire MK llc, lll, XV XVll: 2,115 aircraft.
However "The first Westland built Spitfire flew in July 1941, and production continued as part of the company's main wartime activity." The Seafire XV XVll being built From 1944 and four squadrons were working up with Seafire XVs when the war terminated.
btw, even 2700 planes over 6 years (312 weeks) is only about 8.6 planes per week. Granted the 1945/46 production was probably at a slower pace than war time.
Westland also built 18 Fairey Barracudas before that project was stopped. ( Really...18 How much time and effort was spent on tooling and arranging factory space for that.
Westland was also responsible for of the modification all Mohawk, Tomahawk and Kittyhawk fighter provided to Britain to RAF standard.
Design work for the Welkin started in 1940 with first prototype flying 1 November 1942.

3. "Always forgotten, or ignored, is that the Air Ministry had already turned down Vickers' proposal for the Type 327 (two Merlins + 6 x 20mm cannon,) so the Whirlwind was always on a knife-edge."
True but a large part of the reason for the Air Ministry turning down Vickers' proposal was that it was actually the Supermarine Type 327 and while Supermarine was owned by Vickers the Air Ministry figured Supermarine had enough on their plate getting the Spitfire into production.

The British did not always make the best use of their production capability but then NO country did as requirements often changed faster than than production could (tooling and resource allocations often are made months (many months) before production examples are completed.)

edit.> I would also note that when the decision to end Whirlwind production was made in May of 1940, the Lysander was still viewed as a viable (and valuable) warplane. Even as the decision was made (or with in just a few weeks) this was shown to be untrue in no uncertain terms. The Lysander was no more suitable for tactical duties than the Fairey Battle. Out of 10 squadrons of Battles in France just under 200 planes were lost from all causes before the last flew to England on June 15th. Out of 5 squadrons of Lysanders 118 were lost from all causes out of 175 deployed.
Favoring Lysander production over Whirlwind production (with hindsight) was a mistake unless there other things slowing Whirlwind production (delivery of engines? landing gear? magnesium alloy?).

 

[Glider]

It is astonishing how the mere mention of the Whirlwind brings out the rose-coloured spectacles.
The Peregrine could only use 100 octane fuel in emergencies (whatever the Pilot's Notes say); to have modified it to full 100 octane capability would have meant many hours, and a new Mark of engine, so the possible use of the Merlin supercharger is academic.

The Whirlwind operated for some time on standard RAF fuel be it 87 or 100 octane. Using 100 octane may not give you any additional power but equally is unlikely to do any damage and as a stopgap until the Typhoon had sorted its troubles out it would have been invaluable.

The Peregrine could only be produced in the Derby Rolls-Royce factory, and R-R calculated that each one would have meant the loss of 2 Merlins, and delay of the entry of the Griffon.

I admit to not getting this argument. The engine production could have been moved to another factory, or production could have been increased in its current facility. The decision to stop production of the aircraft by default stopped any investment in the production of the engines. Remember no development was needed so I don't see how the development of the Griffon would be impacted as this was at that stage a research and development / prototype project.

The decision to stop building the Whirlwind was first made by Freeman in May 1940, and endorsed by Beaverbrook in October, long before any need for a dedicated ground-attack aircraft showed itself; Westland's output was turned over to Spitfires/Seafires in July 1941, and the RAF were delighted with the capability of the Hurricane in the desert, asking for as many IID as could be produced.

Beaverbrook stopped the development of almost all aircraft in May 1940to concentrate resources on key aircraft, it wasn't specific to the Whirlwind. A decision that was very controversial at the time and delayed the production of a number of valuable types. The RAF were far from delighted in the performance of the Hurricane in the desert. They had the measure of the Italians but when the Luftwaffe turned up it was a different story. The Whirlwind was a much better aircraft that the Hurricane in the GA role being faster, better armed with a slightly better range. As for the Hurricane IID they couldn't wait to get rid of them as they were too specialised and vulnerable.

Westland could only produce 2 Whirlwinds per week, never enough to equip any force of any size, and certainly not enough to cover "wastage." They produced 2157 Spitfires Seafires in six years; to produce that many Whirlwinds would have taken 20+ years. Would you also be happy to leave Malta, the Desert Air Force, Australia, and the Navy with no means to defend themselves, apart from American aircraft?

Had the resources been made available then production would have increased. As has been pointed out if the RAF had cancelled production of the Lysander then capacity was available. Had the development and production of types such as the Botha (an aircraft that was never going to achieve anything) and the Blenheim V been cancelled, capacity would have been available. Had the Battle been cancelled (a proven failure) capacity (and Merlins) would have been available.

Production capacity, in this country, was finite, due to the available numbers of factories, and always open to attack, as seen in the destruction of the Supermarine Eastleigh factory; new buildings, machine tools, jigs and workers couldn't be whistled up out of thin air, and a six-day working week was already normal.

I think I have covered this point.

Always forgotten, or ignored, is that the Air Ministry had already turned down Vickers' proposal for the Type 327 (two Merlins + 6 x 20mm cannon,) so the Whirlwind was always on a knife-edge.

Always forgotten or ignored is that fact that the Whirlwind was a proven asset by the end of March 1941. As to how well it did the following is worth considering. Standard RAF planning was that for a front line fighter in Europe a squadron needed 50 aircraft to stay operational for six months. Which is why aircraft such as the Whirlwind and the Spitfire XII were ordered in batches of about 100. The Whirlwind operated for at least two years on the front line. It was popular with the crews and the first real strike / GA aircraft in the RAF.

 

[Shortround6]

Sometimes decisions were made on perceptions of capability rather than actual facts. Early use of the Whirlwind (before bomb racks) often had them assigned to over water patrols at further distances from land than Spitfires due their twin engine safety. This capability was somewhat of an illusion due to the non-cross feed fuel system (dead engine tanks could not feed the good engine) and non feathering propellers. dead engine was always going to windmill somewhat even in course pitch even if the engine damage allowed the pitch to be changed. There may also be a question as to if both engines had a full set of "accessories" like generators and hydraulic pumps.

The Whirlwind was unlikely to make to the end of the war no matter what but there were certainly a number of things that could have been fixed/altered on a MK II or III version without going to Merlins or Merlin superchargers or major redesigns of the airframe.

Better air intake for better use of Ram?
Better Exhaust system for more exhaust thrust?
Both may offer better performance at altitude without changing the basic engine.
Cross feed fuel system and fully feather props. better ability to return on one engine.
Belt fed guns for more ammo capacity.
Add 3rd external station under fuselage for either bomb or fuel tank. And/or plumb under wing racks for fuel.

If it is to be a ground pounder aircraft change the gear ratio to the supercharger (even if left single speed) to lower the full throttle height and pick up take-off power and low altitude power keeping the same boost limits.
Peregrine version of Merlin VIII? Merlin VIII picked up almost 200hp for take-off over a Merlin III using the same RPM and boost on 87 octane fuel. Peregrine might pick up 150-160hp? Merlin VIII gave 1275hp at 3000ft at 9lbs boost. Low altitude Peregrine might be good for 950-960hp at the same conditions?

Fuselage fuel tanks sort of depend on the guns. If you leave two up and two down there might not be room for a forward fuselage tank. Without the forward tank how big a rear tank can you put in and keep the CG in balance? Four guns line down low may leave room of fuel tank (depends on the feeds).

 

[tomo pauk]

...
The Whirlwind was unlikely to make to the end of the war no matter what but there were certainly a number of things that could have been fixed/altered on a MK II or III version without going to Merlins or Merlin superchargers or major redesigns of the airframe.

Whether it will make it until the end of the war - depends how much effort is invested in the aircraft?

Better air intake for better use of Ram?
Better Exhaust system for more exhaust thrust?
Both may offer better performance at altitude without changing the basic engine.
Cross feed fuel system and fully feather props. better ability to return on one engine.
Belt fed guns for more ammo capacity.
Add 3rd external station under fuselage for either bomb or fuel tank. And/or plumb under wing racks for fuel.

+1 on all of this.
As far as I can deduce from the schematics, the carburetor air entered 1st the wing-located 'hole', then was routed towards the nacelle, then routed down to the carb, then routed again into supercharger. A path similar to the F4U? That makes the air taking 3 times the 90 deg turn, and the 'harvesting' of the ram air surely was nothing to brag about. So - keep it simple: an intake tube at the top of nacelle, just behind the prop.

Fuselage fuel tanks sort of depend on the guns. If you leave two up and two down there might not be room for a forward fuselage tank. Without the forward tank how big a rear tank can you put in and keep the CG in balance? Four guns line down low may leave room of fuel tank (depends on the feeds).

With beard radiators introduced, the inboard part of the wing is free to have extra fuel oil tankage. Alternatively, if a pair of cannons is relocated under belly, there the ammo belts can be located there, but with less extra fuel.
Such a location of radiators also simplifies the layout of the flaps.
Alternatively, install the radiators in front of the front spar, with the leading edge area of the wing enlarged accordingly.

The Wirlwind was not just looks, though it scored max points there.
It featured a 360 deg canopy quite early on, choice of high-lift devices was impeccable, the Hispanos installed were not just powerful, but a rigid fuselage mount kept them trouble-free, U/C was fully retractable covered, the radiator system was partially copied many times on later aircraft.

 

[wuzak]

With beard radiators introduced, the inboard part of the wing is free to have extra fuel oil tankage.

I think the beard radiators will lose some performance compared to the leading edge radiators.

Just found this cutaway.

http://aviadejavu.ru/Images6/AE/AE73-6/38-1.jpg

I think what you were saying about the radiators is if they went for a proper le radiator (Mosquito style) there wouuld be space in the wing for fuel.

Looks like there is no chance of a fuel tank ahead of the cockpit.

 

[Edgar Brooks]

I admit to not getting this argument. The engine production could have been moved to another factory, or production could have been increased in its current facility.

Then why were Ford and Packard needed, for extra production? R-R maintained they had no capacity available, and nobody has ever produced concrete evidence that they lied.

The decision to stop production of the aircraft by default stopped any investment in the production of the engines. Remember no development was needed so I don't see how the development of the Griffon would be impacted as this was at that stage a research and development / prototype project.

The need for improvements to the engine, to enable it to use 100 octane 100% of the time, was one of the reasons for the cancellation of the engine, which led to cancellation of the aircraft, not the other way round. R-R said to continue with the engine would have an impact on the Griffon; they were there, with a Ministry-appointed Local Technical Committee and Resident Technical Officer in situ, keeping careful watch, plus a Factory Overseer, usually a Wing Commander, appointed by the RAF, so any hint of them telling lies would have had serious repercussions, in a time of war.
The Griffon was originally planned for the Spitfire IV, in December 1939, and was undergoing flight trials, in a Henley, in 1940, so any delay would not have been well received. The first Griffon-powered Spitfire flew 27-11-41.

The Whirlwind was a much better aircraft that the Hurricane in the GA role being faster, better armed

Four cannon + 240 rounds against four cannon + 370 rounds is better armed?

As for the Hurricane IID they couldn't wait to get rid of them as they were too specialised and vulnerable.

Is that why they asked for three Squadrons of IID in the desert?

Had the resources been made available then production would have increased.

Leave out the "made," and you've got it right; there was no extra capacity in Westland, so output could not be increased.

As has been pointed out if the RAF had cancelled production of the Lysander then capacity was available. Had the development and production of types such as the Botha (an aircraft that was never going to achieve anything) and the Blenheim V been cancelled, capacity would have been available. Had the Battle been cancelled (a proven failure) capacity (and Merlins) would have been available.

But they weren't (and it was up to the Air Ministry to cancel aircraft production, not the RAF,) so it wasn't, and using 20/20 hindsight is a pointless exercise.

Always forgotten or ignored is that fact that the Whirlwind was a proven asset by the end of March 1941.

Not to Fighter Command, they weren't; they were kept well out of the way, during the Battle, with their use only being planned in the event of an invasion.

As to how well it did the following is worth considering. Standard RAF planning was that for a front line fighter in Europe a squadron needed 50 aircraft to stay operational for six months. Which is why aircraft such as the Whirlwind and the Spitfire XII were ordered in batches of about 100. The Whirlwind operated for at least two years on the front line. It was popular with the crews and the first real strike / GA aircraft in the RAF

Fighter Command asked if the Whirlwind could carry bombs, in July 1942, a full year after the Hurricane had been successfully tested with them.
The initial order for the Whirlwind was for 200, not 100, aircraft, and deliveries ceased after 114 had been built. The Spitfire XII was ordered because of a shortage of low-altitude Merlins, so the Griffon had to be used; producing Whirlwind airframes, for which there were no engines, would have been utterly pointless.

 

[wuzak]

Not to Fighter Command, they weren't; they were kept well out of the way, during the Battle, with their use only being planned in the event of an invasion.

It is my understanding that there weren't enough serviceable Whirlwinds to form a unit which could participate in the BoB anyway.

 

[GregP]

Avro took the Manchaster and made it into the 4 engine Lancaster, with what might be modestly described as good results. The Whirlwind could have been fitted with a new wing able to handle Merlins. The new wing could also have been a better high-speed airfoil.

The trouble with reinventing a design like the eye-catching WHirlwind is figuring out how much trouble it would have been versus designing completely new aircraft. A large part of the design is the wing and engine stressing for a conventional twin layout.

Had Westland decided to go that way, they could have started with a Whirlwing fuselage as a stop-gap and then continued with a fresh, new fuselage design for the new wing and engines, had it been required.

I'm not sure I"ve ever seen it done that way, but there is nothing saying it couldn't have been done that way, and proceeding in that manner could have resulted in a potent fighter in a resonably short time ... and time was paramount in the late 1930's. It might have taken some fresh thinking, but that's what designers do ... look at the needs and come up with something to meet them.

 

[Shortround6]

Four cannon + 240 rounds against four cannon + 370 rounds is better armed?

This particular argument is getting old. You are comparing a 1940 fighter with drum fed cannon to a 1941 fighter that had belt fed cannon. Early 20mm Spitfires only had 60 rds per gun but were changed to 120rpg with belt feed in later models. First 400 Beaufighters had 60rd drums ( and a 2nd crew man to change them) but the 401st and all later ones got belt fed guns. There were 2 if not 3 different noses for the Whirlwind using pneumatic powered magazines with 110-120 rpg. (one mock up nose held 4 20mm guns and three .303s another nose held twelve .303 guns. At least one (if not two) were test fired on the ground even if not air tested (the air bottles feeding the pneumatic system were too small and ran out of air before the magazines ran out ammo). There doesn't seem to any reason at all why the Whirlwind could not have used belt fed guns had they wanted to or been allocated them. Drum fed guns having to be placed on their sides in the single engine plane wings to avoid high drag.

Leave out the "made," and you've got it right; there was no extra capacity in Westland, so output could not be increased.

True, there was no extra capacity at Westland because they were turning out the war winning LYSANDER at about 3 times the rate they were building Whirlwinds at the air ministries request.

Planes on the left side of the wall????

 

[GregP]

The Lysander might have been a damed good liaison aircraft, but it wasn't a war winner in any sense of the word. Is was a covert aircraft, not a combat aircraft.

 

[tomo pauk]

...

Planes on the left side of the wall????

Superb picture, and on-topic.

 

[GregP]

Planes on the left side look to me to be Lysanders.

1) raidal engine
2) 3-blade prop
3) Landing gear matches a Lysander
4) Taken at Westland

Hhmmm .... must be .... Lysanders.