Westland Whirlwind revisited

tomo pauk said:

Seems like 30 of the He 112s were delivered to Romania, 19 to Spain, per German-language Wikipedia.

As for the E-1, by Radinger ans Shick book about the early Bf 109s, FWIW:

Or, per Google translate, my remarks in brackets:

In mid-1940, the troupe [units] rejected the E-1 due to inferiority in use. Thus, from August 1940, a conversion of the still existing E-1 single-seat aircraft on [a standard of] E-4 or E-7 (DB 601 N, reinforced armament) and the remaining 175 E-1 (lt.Lieferplan [per delivery schedule]) came as E-7 N for delivery.

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What's his source? That's an old book. The BAL was accepting E-1s in September. That still doesn't account for all the other E-1s already with the units, they had to be released from their units for the conversion. Whether they would have to return to Germany I can't say without some investigation, but in 1940 I expect that they did.

Incidentally, the delivery of the 601N was a debacle because the RLM kept changing its mind about which aircraft should get it.

stona said:

What's his source? That's an old book. The BAL was accepting E-1s in September. That still doesn't account for all the other E-1s already with the units, they had to be released from their units for the conversion. Whether they would have to return to Germany I can't say without some investigation, but in 1940 I expect that they did.

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Unfortunately, source for the text is not sourced/footnoted. Book is issued in 1997.

Incidentally, the delivery of the 601N was a debacle because the RLM kept changing its mind about which aircraft should get it.

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Yes, the DB 601N was a PITA, both from the reliability and avialbilty points of view.

Kevin J said:

It was faster until over boosting came along in the second half of 1942.

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and this the problem with evaluating the Whirlwind today.

We are comparing a 1940 aircraft to 1941 or 1942 aircraft. Yes the Whirlwind was used in 1942 and for a good part of 1943 but aside from allowing 9lbs of boost (correction welcome) and adding the bomb racks the plane was unchanged from 1940.

Anybody want to guess at how well the Tomahawk would have done over Europe in the summer of 1943?


as to how soon the Whirlwind could have been in squadron service (real squadron service, not 1st squadron with 3-4 planes figuring out how to write the pilots manual) that rather depends on RR and the Air Ministry. I have no idea when or how fast RR was delivering the Peregrine engines in the spring of 1940, a major consideration, Westland cannot build planes without engines. However Westland was delivering 5-7 Lysanders per week from the same building as the Whirlwind so there was definitely work force and factory space available had somebody decided before the Battle of France that the Lysander was not the be all and end all of Army cooperation and close support planes.

The Whirlwind was used as a strike aircraft for most of it's career even before the bomb racks showed up. Four 20mm guns were a rather formidable gun armament in 1941 even if pretty routine in 1943/44. Their effectiveness may have been a bit overrated by the powers that be. Few people in 1943 and after thought that four 20mm cannon alone were effective anti shipping or effective air field attack armament. But in 1941 the Whirlwinds were sent on many anti-shipping, airfield strafing and train wrecking missions with only the their 20mm guns.

Shortround6 said:

and this the problem with evaluating the Whirlwind today.

We are comparing a 1940 aircraft to 1941 or 1942 aircraft. Yes the Whirlwind was used in 1942 and for a good part of 1943 but aside from allowing 9lbs of boost (correction welcome) and adding the bomb racks the plane was unchanged from 1940.

Anybody want to guess at how well the Tomahawk would have done over Europe in the summer of 1943?


as to how soon the Whirlwind could have been in squadron service (real squadron service, not 1st squadron with 3-4 planes figuring out how to write the pilots manual) that rather depends on RR and the Air Ministry. I have no idea when or how fast RR was delivering the Peregrine engines in the spring of 1940, a major consideration, Westland cannot build planes without engines. However Westland was delivering 5-7 Lysanders per week from the same building as the Whirlwind so there was definitely work force and factory space available had somebody decided before the Battle of France that the Lysander was not the be all and end all of Army cooperation and close support planes.

The Whirlwind was used as a strike aircraft for most of it's career even before the bomb racks showed up. Four 20mm guns were a rather formidable gun armament in 1941 even if pretty routine in 1943/44. Their effectiveness may have been a bit overrated by the powers that be. Few people in 1943 and after thought that four 20mm cannon alone were effective anti shipping or effective air field attack armament. But in 1941 the Whirlwinds were sent on many anti-shipping, airfield strafing and train wrecking missions with only the their 20mm guns.

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To me, the Whirlwind represents over complexity for the task it has to perform. Two engines instead of one, twice the price of a Supermarine built Spitfire, performing a task that could be just as well performed by a cheaper aircraft, the Hurricane IIc, or a comparably priced aircraft, the Mustang Ia. It required Rolls-Royce to duplicate Merlin development on an engine only used in one airframe, it wouldn't make economic sense. Even if the engines are replaced with the Taurus and it's sent to the Far East, it's only as good as the CGI. RADAR wasn't really sorted out and working properly in India until 1943 IIRC. In Malaya there was no observer corps to cover the radar gaps.

Kevin J said:

To me, the Whirlwind represents over complexity for the task it has to perform. Two engines instead of one, twice the price of a Supermarine built Spitfire, performing a task that could be just as well performed by a cheaper aircraft, the Hurricane IIc, or a comparably priced aircraft, the Mustang Ia. It required Rolls-Royce to duplicate Merlin development on an engine only used in one airframe, it wouldn't make economic sense. Even if the engines are replaced with the Taurus and it's sent to the Far East, it's only as good as the CGI. RADAR wasn't really sorted out and working properly in India until 1943 IIRC. In Malaya there was no observer corps to cover the radar gaps.

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You are discussing the end use of it, not what it was commissioned for. It was initially designed and purchased to get a 4 cannon armed fighter in the air, at a time when aircraft had so little power that you needed two engines to get 4 cannon into the air. It only became possible to mount cannon in the wings of S/E aircraft in late 1940 and belt feed came later. Most fighters descended into the ground attack or fighter bomber role, it was rarely their primary role as designed.

Kevin J said:

To me, the Whirlwind represents over complexity for the task it has to perform. Two engines instead of one, twice the price of a Supermarine built Spitfire, performing a task that could be just as well performed by a cheaper aircraft,

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Your comment here reminded me of the SNCAC NC-600.

Admiral Beez said:

Your comment here reminded me of the SNCAC NC-600.

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Never heard of that plane before.

Kevin J said:

Never heard of that plane before.

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An attractive twin engine heavy fighter doing a job that a cheaper single engine fighter could do. Still sweet looking though....from some angles.

Kevin J said:

To me, the Whirlwind represents over complexity for the task it has to perform. Two engines instead of one, twice the price of a Supermarine built Spitfire, performing a task that could be just as well performed by a cheaper aircraft, the Hurricane IIc, or a comparably priced aircraft, the Mustang Ia. It required Rolls-Royce to duplicate Merlin development on an engine only used in one airframe, it wouldn't make economic sense. Even if the engines are replaced with the Taurus and it's sent to the Far East, it's only as good as the CGI. RADAR wasn't really sorted out and working properly in India until 1943 IIRC. In Malaya there was no observer corps to cover the radar gaps.

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The Whirlwind was caught by time, It took, like many British aircraft, too long to get into quantity production and into service. The Mock up was inspected at the end of May 1937 and after many delays the prototype flew 11th Oct of 1938, about 4 months late. The Hurricane I with four cannon only became viable with the Merlin XX engine.
Hooker only went to Work for RR in Jan of 1938 so there was very little time to develop the Merlin XX and 45 supercharger before Production contracts for the Whirlwind were placed.
The first production Whirlwinds were leaving the factory before the NA-73 Mustang prototype ever flew and the last Whirlwind left the factory in Jan 1942 while the first P-51 with 20mm guns flew on May 29th 1942.

You are correct in that the Peregrine really didn't make economic sense but then the whole Napier Sabre fiasco never made economic sense either. It's use dropped from a multitude of projects to just the Typhoon/Tempest line of aircraft, in part due to the protracted troubles and in part due the shortages of the engine, all available engines being needed for the Typhoon (in part due to atrocious engine life early in it's career).

Instead of comparing the Whirlwind to the Hurricane II C and the P-51 try comparing it to the Typhoon/Tornado. On 10th of July 1939 the air ministry had ordered 500 of each even though flight test engines would not be delivered until Dec of 1939 in each case.

Again, what could be accomplished in 1937-39 on 87 octane fuel was just a fraction of what could be accomplished in 1941-42 with 100/130 fuel.

BTW, the Taurus was a Lemon, another way, way too expensive engine for what it delivered. Service engines overheated and made the Peregrine look like a stratosphere engine.

Admiral Beez said:

An attractive twin engine heavy fighter doing a job that a cheaper single engine fighter could do. Still sweet looking though....from some angles.

View attachment 559616

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Use two 700hp engines at a time when the French were very lucky they could get 1100h from a single engine.
Details are sketchy (and don't always agree?) but it did carry the weapons of a Bloch 152 but was faster and longer ranged.
Bloch may have had a better view from the cockpit though. This plane looks pretty dismal.

Shortround6 said:

You are correct in that the Peregrine really didn't make economic sense but then the whole Napier Sabre fiasco never made economic sense either. It's use dropped from a multitude of projects to just the Typhoon/Tempest line of aircraft, in part due to the protracted troubles and in part due the shortages of the engine, all available engines being needed for the Typhoon (in part due to atrocious engine life early in it's career).

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With hindsight the Sabre fiasco seems like a mistake.
However, when the decision was taken to proceed with its development there was more at stake than the promise of the engine itself.
The Air Ministry always believed that quality could only be assured by competition between the different firms and the rapid contraction of the aero engine industry during the 1930s was the cause of much concern. As early as 1st July 1935 Sir Christopher Bullock, Permanent Under-Secretary at the British Air Ministry, was writing that it was,

"essential that Messrs. Napiers should be kept alive as a separate entity, in order to prevent the engine industry being constituted on too restricted a basis."

In February 1937 Freeman was alarmed that,

"the loss of the experienced personnel making up the technical division [of Napier] would be a serious loss to the RAF."

It got worse. By May 1939 he was expressing his concern that both Napier and Armstrong Siddeley were on the verge of leaving the aero engine business altogether.

"It was a most unhealthy position" he wrote "for the Air Ministry to be substantially dependent upon two firms only."

The development order for six Sabres was placed in 1937, coinciding with plans for a new Sabre engined fighter to replace the Spitfire and Hurricane (eventually the Typhoon). There were on going problems with the development of the next generation engines from the other two firms. The R-R Vulture suffered repeated failures during 1939. The Bristol Centaurus was still a very long way from being a production engine, and the production arrangements for the Hercules had been pushed through by the Air Ministry before it was certain that it would be a successful engine.

The decision to gamble on the Sabre was based on two factors. First, the Sabre would provide a third option should the Vuture and Centaurus fail. Second, It would keep Napier in the aero engine business, something that was considered essential by the Air Ministry at the time. On this basis it doesn't seem quite the disastrous mistake that the Sabre would make it seem. Nobody could know in 1937 that the Sabre would turn into one of the most difficult and costly of all pre-war development projects.

stona said:

With hindsight the Sabre fiasco seems like a mistake.
However, when the decision was taken to proceed with its development there was more at stake than the promise of the engine itself.
The Air Ministry always believed that quality could only be assured by competition between the different firms and the rapid contraction of the aero engine industry during the 1930s was the cause of much concern. As early as 1st July 1935 Sir Christopher Bullock, Permanent Under-Secretary at the British Air Ministry, was writing that it was,

"essential that Messrs. Napiers should be kept alive as a separate entity, in order to prevent the engine industry being constituted on too restricted a basis."

In February 1937 Freeman was alarmed that,

"the loss of the experienced personnel making up the technical division [of Napier] would be a serious loss to the RAF."

It got worse. By May 1939 he was expressing his concern that both Napier and Armstrong Siddeley were on the verge of leaving the aero engine business altogether.

"It was a most unhealthy position" he wrote "for the Air Ministry to be substantially dependent upon two firms only."

The development order for six Sabres was placed in 1937, coinciding with plans for a new Sabre engined fighter to replace the Spitfire and Hurricane (eventually the Typhoon). There were on going problems with the development of the next generation engines from the other two firms. The R-R Vulture suffered repeated failures during 1939. The Bristol Centaurus was still a very long way from being a production engine, and the production arrangements for the Hercules had been pushed through by the Air Ministry before it was certain that it would be a successful engine.

The decision to gamble on the Sabre was based on two factors. First, the Sabre would provide a third option should the Vuture and Centaurus fail. Second, It would keep Napier in the aero engine business, something that was considered essential by the Air Ministry at the time. On this basis it doesn't seem quite the disastrous mistake that the Sabre would make it seem. Nobody could know in 1937 that the Sabre would turn into one of the most difficult and costly of all pre-war development projects.

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Also, without the Sabre, the RAF wouldn't have a fast low altitude fighter to counter the Fw 190A until the Spitfire XII in 1943.

stona said:

"It was a most unhealthy position" he wrote "for the Air Ministry to be substantially dependent upon two firms only."

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It's a fair position, and one I'd wish the BrIrish government had taken with the postwar automobile industry instead of forcing mergers and nationalizations that reduced the industry to dust.

Kevin J said:

Also, without the Sabre, the RAF wouldn't have a fast low altitude fighter to counter the Fw 190A until the Spitfire XII in 1943.

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If the Centaurus has been expedited it would have done the trick. What took so long with that motor?

Admiral Beez said:

If the Centaurus has been expedited it would have done the trick. What took so long with that motor?

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Sleeve valves

A bit more seriously and it part answer to

Admiral Beez said:

It's a fair position, and one I'd wish the BrItish government had taken with the postwar automobile industry instead of forcing mergers and nationalizations that reduced the industry to dust.

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Bristol (Roy Fedden) had not figured out how to make sleeve valves in large quantities at acceptable qualities in the late 1930s. They were developing the Centaurus before the Taurus and Hercules had made it into large scale production. It should have been easy in principle Just stick two Perseus engines together and lengthen the stroke (or add two cylinders to each row of a Hercules and lengthen the stroke (They all used the same bore). But the devil was always in the details and things were not a simple as they appeared. They weren't for a lot of engines at this time as both RPM and cylinder pressures were rising. Roy Fedden was not an easy man to work with and the Board of Directors of Bristol (Who managed a company with more than Bristol aircraft engines and Bristol airframes) had had enough and fired Fedden in 1942, Fedden had near bankrupted the entire company while developing the sleeve valve concept/early engines. But without Fedden's drive the Centaurus project slowed down (combined with the insatiable demand for Hercules engines).

A Certain amount of competition between companies is a good thing, too much and each design team is too small and too slow to get their ideas to market (a problem the British aero industry had in the 1930s) and in the 1950s the Labor Party was trying punish any company they thought had made big profits while trying to save as many jobs in small aout dated companies as possible. They not only wrecked the british car industry but the wrecked the aero industry as well. However it was reaching a point where the small companies of England could no longer compete in the world markets. It was said the Boeing had more engineers/draftsmen working in the landing gear dept than the 3 major British airplane makers in the early 50s had combined working on everything, perhaps not true but the british were tipped a bit too far to the small side. Unfortunately just jamming companies together with little regard for actual products and manufacturing capability didn't produce the claimed efficiencies.

Back in the 30s the "official" position on keeping competition alive in the aero engine industry did not extend to either Fairly or Alvis ( licenced the French Gnome-Rhone engines).

Despite all that, the Centaurus first ran in July 1938 and was type tested in 1939 at 2,000hp. In October 1941 a Hawker Tornado powered by the CE.4S prototype flew at 421 mph. The 2 speed supercharged Centaurus (I presume the Mk V) wasn't cleared for production until late 1942.

If the delay was not technical then it can only have been due to the company's inability to get the engine into full scale production (it built more than 54,000 Hercules engines alone, which kept it busy) compounded by a lack of interest from the Air Ministry.

I am not sure about lack of interest at the Air Ministry. The 2nd Vickers Warwick bomber Flew on the 5th of APril 1940 with a pair of Centaurus engines. Production contract for MK Is with P & W R-2800s was placed in Jan 1941 as was a contract for MK II's with Centaurus engines. But it is not until mid 1943 that a prototype MK II was built.
With the Vulture canceled and the Sabre in real difficulties the Centaurus should have been fairly high on the priority list?

Shortround6 said:

With the Vulture canceled and the Sabre in real difficulties the Centaurus should have been fairly high on the priority list?

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The Hercules, in use in existing types, was an even higher priority.

Admiral Beez said:

If the Centaurus has been expedited it would have done the trick. What took so long with that motor?

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Bristol were busy sorting/improving the Hercules.

The Whirlwind had its own problems, not least of which was that Westland was a small firm that bit off more than it could chew in terms of production estimates - it just couldn't meet them. There was a plan to built them at Castle Bromwich - 800 of them! But this was sensibly changed to the Spitfire. Canning the Peregrine spelled the end for the Whirly, despite any promise it had, and alternatives were investigated; Fedden at bristol pushed for a Hercules powered variant but Petter knew that was impossible - it would require an entire redesign.

Production difficulties added time to the requirement as Westland at Yeovil had no real mass production experience and this stymied development, adding delays. It was also a complex airframe and issues with things like the slats had to be countered - these were eventually permanently closed as they had a tendency to snap open violently and tear off the wing. It was found during trials at Farnborough that the airframe was too draggy as well, so work was done in streamlining it. It also was affected by compressibility effects, but these were not fully understood at the time. It also had a peculiar design innovation where the engine cowl flaps were interconnected with the flaps, so when these were opened the flaps had to be lowered!

Somewhat oddly, the Whirlwind was not officially disclosed by the Air Ministry until August 1941 despite the design appearing in Observer Corps recognition manuals before then - odd. Even by the end of 1940, a few months after it entered service, the Air Ministry considered its lack of altitude performance - it was faster than a Spit I at low level - a hindrace and bordering on obsolescence.