Westland Whirlwind revisited

[Shortround6]

The Griffins eventually went to around 2500hp not counting some of the really weird ones.

A two stage two speed Griffin was about 375lbs lighter than a single stage two speed Vulture.

 

[wuzak]

Right, 2,500hp post war for the Griffon. Min 100/130 fuel. +25psi boost.

The Vulture 2,500hp potential in 1940 (reliability didn't allow it practically). 100 octane fuel.

1,800hp +6psi boost (Vulture II) and 1,955hp +9psi boost (Vulture IV/V).

By 1945 a developed Vulture should easily exceed 3,000hp.

 

[stona]

Doh. The Bf 109s in the BoB carried two cannons as a rule, unlike the Spitfires.

Not as a rule.

Of 740 serviceable Bf 109s on 31 August 1940, 307 were Bf 109 E-1s, 103 were E-3s, 304 were E-4s and 27 were E-7s.

Some of the E-1s might have been converted to cannon, that would be difficult to ascertain. They should have had the designation changed, but we know that did not always happen. Conversion from E-1 to E-3/4 standard was not a job that could be done in the field.

The 100 E-1s delivered up to the end of September were accepted and delivered as E-1s. I find it difficult to believe that these were cannon armed. They would not have been manufactured and accepted by the BAL under the specific designation E-1 if they were. Remember that the E-1 and E-3 were being produced concurrently, there is a reason for the different designations.

Bergstrom has calculated that roughly 40% of Bf 109s flying in the BoB were armed with just four machine guns.

Edit: I just checked. Exactly one He 112 flew in Spain, three in Hungary, at most twenty four in Romania. If that's 'entering service' so be it.

 

[Admiral Beez]

How about some engines from Power Jet?

Not as a rule.

That's interesting. As a lad first living in Britain and then growing up in the 1970s in Canada I was an avid reader of Battle and Warlord the two things drilled into my head were Spitfires were better than Hurricanes and the Me 109 (they never called it the Bf) had that 30mm cannon in the nose.

 

[stona]

RR may have seen (my opinion here) the Griffon as a lower cost, lower risk engine engine to get them the same power as the Vulture once they had the better fuel and been willing to dump the Vulture.

Definitely, but to compete with the Sabre, not their own Vulture..

R-R was concerned that Napiers were being revived by the Air Ministry with the Sabre contract(s) and the building of a factory in Liverpool with a projected capacity of 2,000 Sabres per year.
Though in 1939 R-R still saw the Vulture as the engine most likely to compete with the Sabre there seem to have been some doubts about it within the company. This is undoubtedly why R-R pursued what was to become the Griffon project from early 1939. The company argued that the necessary technology for the engine already existed, in February 1939 Hives was writing to Freeman,

"The fact that the engine follows closely on the Rolls-Royce standard design, and the fact that we have an engine of such dimensions on which we shall shortly be running an endurance test, and also the fact that it is similar to the 'R' engine, means that we are taking the minimum risk; far less than when jigs and tools are ordered for new aircraft."

R-R was hedging its bets. At the same time that it was professing the intention of concentrating on fewer models, a policy which would lead to the deletion of the Peregrine and sound the death knell of the Whirlwind, it was offering a new engine to the Air Ministry and manufacturers to head off competition from Napiers.

R-R hoped that the Griffon would give a longer production life to existing airframes and dispel the challenge of an alternative Sabre powered fighter. The company had a long standing relationship with Supermarine who were obviously keen to extend the production life of the Spitfire. Supermarine were scheduled to change over from the Spitfire to the Beaufighter in 1941. Both companies had a powerful ally in Freeman, who would write in late 1939,

"In wartime when it is difficult to introduce new types of aircraft without a great falling off of production, it is essential that we improve the performance of the types which are already being produced."

We tend to think of the Griffon Spitfire as a late war aircraft, which it was due to the huge improvements made with the Merlin. Supermarine and Roll-Royce had a scheme for installing the Griffon in the Spitfire shortly after the outbreak of the war, as evidenced by a Vickers-Armstrong (Southampton) works report of 23rd October 1939, the second month of the war. It is a quirk of history that the arguments used to support the Griffon were in fact more applicable to the development of the Merlin, but hindsight is a wonderful thing.

Commercial considerations do not disappear during wartime. R-R in particular had an eye on the competition not just during the war but in potential post war markets when making decisions in 1938/9.

 

[Admiral Beez]

Whirlwind's controls. Note only one fuel gauge with switch to go from Starboard to Port tanks. Did they actually have a float level in the tanks?

 

[stona]

How about some engines from Power Jet?
That's interesting. As a lad first living in Britain and then growing up in the 1970s in Canada I was an avid reader of Battle and Warlord the two things drilled into my head were Spitfires were better than Hurricanes and the Me 109 (they never called it the Bf) had that 30mm cannon in the nose.

No Bf 109 before the F series had a motorkanone (firing through the spinner). The two principle variants had an MG 151 15mm cannon (F-2) and an MG 151/20 20mm cannon (F-4). Both retained the two cowl mounted MG 17s of earlier versions. It's armament was thus two rifle calibre machine guns and one cannon, about which not everyone who flew it was thrilled. The F-series didn't really make it in time for the BoB.

The E-1 came equipped with four MG 17 machine guns, two in the cowl mounted on top of the engine (firing through the propeller) and two in the wings.

The E-3 came with the two MG 17 cowl guns and two MG FF 20mm cannon in the wings.

The E-4 and E-7 also came with the two cowl mounted machine guns and two MG FF 'M' 20mm cannon in the wings.

The 30mm motorkanone came later still on G and K series Bf 109s.

 

[Schweik]

Somebody mentioned a fairly low dive speed limitation for the Whirlwind of under 400 mph, is that correct? Do we know what the reason is?

 

[stona]

Somebody mentioned a fairly low dive speed limitation for the Whirlwind of under 400 mph, is that correct? Do we know what the reason is?

I've read several accounts in which Spitfires struggled to keep up with Whirlwinds making dive bomb attacks and one from 609 Sqn. in which the Typhoon pilots were surprised by the steep angle at which the Whirlwinds dived.
None of these mention the speed of the dive.
There were issues with aileron flutter in fast dives when carrying two 500lb bombs.

 

[Schweik]

Ok well it sounds like no real problem with dive speed then if Spits struggle to keep up

 

[stona]

Well, the Spitfire didn't have great acceleration and could be out dived by a lot of aircraft. Nonetheless, it doesn't sound like the Whirlwinds were exactly hanging about when they dived

 

[Schweik]

One other way to assess Whirlwind vis a vis the Battle of Britain* (or just afterward) is to compare it to the Me 110.

Me 110 wasn't ideal, but the Luftwaffe certainly got some use out of it. And yet the Whirlwind was considerably better in almost every measurable category:

Comparing Me 110C-1: (per Wikipedia)

• Top speed - Whirlwind 360 mph vs 336 for Me 110 **
• Range - Whirlwind 800 miles vs. ~520 miles for Me 110
• Climb - Whirlwind ~3,000 fpm vs. 2,200 for Me 110
• Dive - (probably) Whirlwind
• Armament - Whirlwind - 4 x 20mm vs. 2 x 20mm with 4 x 7.92 mm
• Power-mass - Whirlwind (roughly .17 for Whirlwind, .14 for Bf 110)
• Fighter bomber - Whirlwind (Me 110 can carry more bombs but Whirlwind can basically function as a dive bomber making it much more accurate)

The only advantage Me 110 seems to have is in Wing Loading (around 33-35 lb / sq ft vs. closer to 40 for the Whirlwind)

Is there any data for roll rate for the Whirlwind? Turning circle?

I would assume Whirlwind would have a better roll since it's smaller and has a shorter wingspan, but one generally shouldn't assume with these things...


* I know Whirlwind wasn't used in the BoB but had more been produced it could have been.
** later variants of Me 110 were faster but Whirlwind could have been improved as well obviously.

 

[Milosh]

The F-series didn't really make it in time for the BoB.

There were a few that were around in Oct, so yes didn`t really make it in time for the BoB.

 

[Schweik]

No Bf 109 before the F series had a motorkanone (firing through the spinner). The two principle variants had an MG 151 15mm cannon (F-2) and an MG 151/20 20mm cannon (F-4). Both retained the two cowl mounted MG 17s of earlier versions. It's armament was thus two rifle calibre machine guns and one cannon, about which not everyone who flew it was thrilled.

By the time F series arrived in the Western Desert the E were quickly relegated to Jabo / fighter-bomber duties. Most pilots there seemed to far prefer the F to the E, and quite a few preferred it to the later G series as well.

 

[stona]

One other way to assess Whirlwind vis a vis the Battle of Britain* (or just afterward) is to compare it to the Me 110.

Me 110 wasn't ideal, but the Luftwaffe certainly got some use out of it. And yet the Whirlwind was considerably better in almost every measurable category:

Comparing Me 110C-1: (per Wikipedia)

• Top speed - Whirlwind 360 mph vs 336 for Me 110 **
• Range - Whirlwind 800 miles vs. ~520 miles for Me 110
• Climb - Whirlwind ~3,000 fpm vs. 2,200 for Me 110
• Dive - (probably) Whirlwind
• Armament - Whirlwind - 4 x 20mm vs. 2 x 20mm with 4 x 7.92 mm
• Power-mass - Whirlwind (roughly .17 for Whirlwind, .14 for Bf 110)
• Fighter bomber - Whirlwind (Me 110 can carry more bombs but Whirlwind can basically function as a dive bomber making it much more accurate)

The only advantage Me 110 seems to have is in Wing Loading (around 33-35 lb / sq ft vs. closer to 40 for the Whirlwind)

Is there any data for roll rate for the Whirlwind? Turning circle?

I would assume Whirlwind would have a better roll since it's smaller and has a shorter wingspan, but one generally shouldn't assume with these things...


* I know Whirlwind wasn't used in the BoB but had more been produced it could have been.
** later variants of Me 110 were faster but Whirlwind could have been improved as well obviously.

You left out the one parameter that crippled the Whirlwind.

The DB 601 powered Bf 110 had a service ceiling close to 33,000 feet and by August 1940 it and the Bf 109 were regularly arriving over the English coast at 30,000 feet.

The Whirlwind lacked performance at altitude. S/Ldr. Eeles who commanded No. 263 Squadron from 6th July to 16th December 1040, and who had a personal investment (career wise) in the aircraft wrote a report in which he conceded

"...the performance of the Whirlwind above 20,000 feet falls off quite rapidly, and it is considered that above 25,000 feet its fighting qualities are very poor."

In the context of the altitudes at which combats were now taking place Dowding would write that it was,

"quite wrong to introduce at the present time a fighter whose effective ceiling is 25,000 feet."

Referring to an earlier proposal to re-engine the Whirlwind with Allison engines (I'm surprised nobody has mentioned this real proposal) he wrote to Beaverbrook on 27th October 1940,

"It is, of course, quite possible that the introduction of American engines might completely alter the performance and characteristics of the type; but, failing that, I recommend that we cut our losses and do not persevere with the Whirlwind as a service fighter type."

With opposition like that, not just Dowding's then position as the officer commanding Fighter Command, but his role in the RAF/Air Ministry throughout the 1930s, it is surprising that the Whirlwind survived at all.

 

[Schweik]

That's true, but the altitude performance of the 110 availed it very little as a day time fighter after 1940. Or even probably by the second half of 1940. It was rapidly outclassed in North Africa, didn't do much in Russia either except as a fighter bomber.

I do understand the position of people like Dowding to not want a fighter that had limited high altitude performance, but I think (and have long argued) with the benefit of hindsight we can see that there was indeed a use for good low to medium altitude fighters, basically everywhere except the Channel front.

And perhaps more importantly, if the Peregrine wasn't cancelled right away, it seems likely they could develop a two speed supercharger for it (or adapt an existing one if that was possible).

As for the Allison, I don't see how that solves the altitude problem (maybe just due to sheer power?), and it isn't much smaller than a Merlin and only 100 lbs lighter more or less right?

 

[stona]

By the time F series arrived in the Western Desert the E were quickly relegated to Jabo / fighter-bomber duties. Most pilots there seemed to far prefer the F to the E, and quite a few preferred it to the later G series as well.

To fly yes, many pilots considered the F-Series the best.

I was referring to the armament.

As Jochen Prien noted in his book on the F,G and K (with Peter Rodeike).

"In contrast to the preceding series the Bf 109 F was armed with only three weapons, one of which was an engine mounted cannon, which Messerschmitt had finally succeeded in introducing into series production. The rather light armament of the F-Series was the subject of considerable controversy from the time of its introduction."

The controversy was several senior officers making their opinion that the type was under armed well known within the Luftwaffe.

 

[Schweik]

Yes but I think many Luftwaffe fighter pilots preferred the Franz to fight, not just to fly. Some didn't to be sure, but many did and said so both at the time and in post-war interviews. If armament was all that mattered they'd be using the Bf 110 right? The value of a fighter in WW2 was a balance of performance, maneuverability, armament, toughness (structurally and things like armor, fuel tank protection) and versatility. Armament wasn't much use if you couldn't get into a 'shooting solution', conversely a lighter armament could be deadly (especially if it included at least one good cannon) if you had enough of a performance / maneuverability advantage that you could own the other aircraft and get right where you needed to be.

I believe the lightly armed, streamlined interceptor / fighter was probably the role to which the 109 was best suited. The need to more heavily arm the aircraft to shoot down B-17s and Il-2s basically led to overloading the airframe and limiting it's agility.

Speaking of protection did Whirlwind have protected fuel tanks and pilot armor?

 

[Kevin J]

Yes but I think many Luftwaffe fighter pilots preferred the Franz to fight, not just to fly. Some didn't to be sure, but many did and said so both at the time and in post-war interviews. If armament was all that mattered they'd be using the Bf 110 right? The value of a fighter in WW2 was a balance of performance, maneuverability, armament, toughness (structurally and things like armor, fuel tank protection) and versatility. Armament wasn't much use if you couldn't get into a 'shooting solution', conversely a lighter armament could be deadly (especially if it included at least one good cannon) if you had enough of a performance / maneuverability advantage that you could own the other aircraft and get right where you needed to be.

I believe the lightly armed, streamlined interceptor / fighter was probably the role to which the 109 was best suited. The need to more heavily arm the aircraft to shoot down B-17s and Il-2s basically led to overloading the airframe and limiting it's agility.

Speaking of protection did Whirlwind have protected fuel tanks and pilot armor?

My understanding of combat between a Thunderbolt and Bf 109G-6 is that the later outperformed the former if clean, but with underwing guns the G-6 was outperformed by the Thunderbolt.

 

[Schweik]

That would also depend on things like type of prop on the P-47, altitude (P-47 was at it's best up high), boost systems (M/W water) on either plane, etc.

But basically yeah.