Westland Whirlwind revisited

[NevadaK]

A simple solution guys. Just add a couple of high power, low weight turbo props. Done and done. Now I will work on the tail issue. Geez. So simple.

Agreed and not out of the realm of possibility.

 

[Wild_Bill_Kelso]

Not sure what your point is. The relative size of engines on other airframes is entirely irrelevant. The problem with the Whirlwind, as others have pointed out, is that it was physically too small to accommodate the Merlin.

An inline engine requires bearers that run either side of the engine itself. That drives a main structural bulkhead that's wider than the engine. In the Whirlwind, that bulkhead was narrower than the Merlin which would require some really strange geometry for the engine bearers to make them wide enough which, in turn, means they likely lack the structural strength to hold the engine.

Show me one example of an inline engine mount where the main bulkhead is narrower than the engine itself. I've never seen one.

Bottom line is that the Whirlwind's manufacturer decided it was impossible to integrate the Merlin into the airframe. Had it been achievable, it would have been done.

Except.... they did it. In the Welkin. See above.

The only thing we are really debating now is could you make a Welkin with shorter wings, and I'm pretty sure you could.

 

[buffnut453]

But the Welkin was a MUCH LARGER airframe. If you have a narrow firewall built just big enough to accommodate the engine bearers for an engine of a given width, then it takes a LOT of redesign to fit a wider engine into that space, either by odd geometry for the engine bearers or implementing a brand new firewall which means a redesign for the entire nacelle.

It's much easier to do if you start with a larger airframe that's actually designed to accept wider engines. It's much harder to do starting small and going larger.

 

[Wild_Bill_Kelso]

But the Welkin was a MUCH LARGER airframe. If you have a narrow firewall built just big enough to accommodate the engine bearers for an engine of a given width, then it takes a LOT of redesign to fit a wider engine into that space, either by odd geometry for the engine bearers or implementing a brand new firewall which means a redesign for the entire nacelle.

It's much easier to do if you start with a larger airframe that's actually designed to accept wider engines. It's much harder to do starting small and going larger.

Looking at them side by side, Welkin has a larger airframe and much wider wings. Much larger airframe? I don't know.

But starting small and going larger is exactly what they did when they went from the Whirlwind to the Welkin.

And the Welkin was in fact made and was viable, it was cancelled because Germans stopped flying Ju 86 high altitude recons after Spitfires shot some down.

All I'm suggesting at this point is you make a Welkin with shorter wings. I think that is definitely possible. The question is, how much drag do you then have, how wide do you need to make the wings to support the engine, and so on.

The Welkin had good performance, but the huge wings mean that maneuverability, in particular roll, would be compromised. For a fighter you'd need smaller wings.

I don't think 60' is out of the question, frankly. Maybe you could go a little less. Would 55' be possible?

A-20 had 61' 4" wings
Beaufighter had 57' 10" wings
Mosquito had 54' 2"
Bf 110 had 53' 4"
Ki-45 had 49' 3"
Pe-3 had 56' 2"
P-38 had 52' wings

 

[tomo pauk]

But starting small and going larger is exactly what they did when they went from the Whirlwind to the Welkin.

Are you claiming that Welkin was a version of the Whirlwind?

And the Welkin was in fact made and was viable, it was cancelled because Germans stopped flying Ju 86 high altitude recons after Spitfires shot some down.

As a deathtrap, Welkin was indeed viable.

 

[Wild_Bill_Kelso]

Are you claiming that Welkin was a version of the Whirlwind?

yes, and I wouldn't be alone in that. From the Wiki:

"Westland put forward their P.14, essentially an adaptation of Westland's Whirlwind fighter layout (and a more experimental twin, the P.13) to meet Air Ministry Specification F.4 of 1940 for a high altitude fighter"

As a deathtrap, Welkin was indeed viable.

The biggest challenge with the Welkin was making the pressurized cockpit and the massive wing (including it's thickness at the root). You would need a different wing for the "Whirlkin" but I don't think that is insurmountable.

 

[tomo pauk]

yes, and I wouldn't be alone in that. From the Wiki:

"Westland put forward their P.14, essentially an adaptation of Westland's Whirlwind fighter layout (and a more experimental twin, the P.13) to meet Air Ministry Specification F.4 of 1940 for a high altitude fighter"

'Fighter layout' is one thing. Typhoon vs. Hurricane, P-47 vs. P-43, Oscar vs. Nate - all of these shared respective fighter layouts.
'Version of a fighter' is something all together different - Spitfire V vs. Mk.I, Yak 9 vs. 7, P-51B vs. A.

So I'd say you're wrong here, and that passage from Wikipedia does not reinforce your claim here.

 

[Wild_Bill_Kelso]

Ok bruh, I'll use the exact language Wikipeida does - Welkin was an "adaptation" of the Whirlwind, which definitely proves the concept that it was possible to "adapt" the Whirlwind by putting Merlins on it, albeit with some other changes to fuselage, tail etc., but these were all done rather quickly.

The greatest difficulties with the Welkin were not mounting the larger engines but rather pressurizing the cockpit and dealing with 70' wings for very high altitude combat. The thickness of the wings and their narrowness in chord is what made them a bit dangerous to fly. You wouldn't need any of that for a low or mid-altitude fighter type.

Whether they started with the Welkin and made a shorter and thinner wing (and maybe with a lower aspect ratio) or start with the Whirlwind and make a bit bigger wing (with maybe a lower aspect ratio) is six of one, half dozen of the other to me. I think it was indeed possible, and you certainly haven't convinced me otherwise.

The Welkin did also incorporate some other improvements such as putting the guns under rather than in front of the nose, and fixing the tail, so it may have made more sense to start with a Welkin than with a Whirlwind, but again, as long as you made the same or equivalent changes, you should be good.

The real question to me I guess is whether the "Whirlkin" would be any better than say, a Beaufighter. Or have complimentary missions profile to it. How was would a Whirlkin with a 55' wingspan be?

 

[Wild_Bill_Kelso]

A Whirlwind with merlin engines on it would be as different from the historical Whirlwind as a P-51A was to a B, most likely.

 

[tomo pauk]

Ok bruh, I'll use the exact language Wikipeida does - Welkin was an "adaptation" of the Whirlwind,

Really? Look here (from here):

Westland put forward their P.14, essentially an adaptation of Westland's Whirlwind fighter layout (and a more experimental twin, the P.13) to meet Air Ministry Specification F.4 of 1940 for a high altitude fighter.[3]

I thought you are above this machinations with sources.

A Whirlwind with merlin engines on it would be as different from the historical Whirlwind as a P-51A was to a B, most likely.

For anyone that believes that, I have the Brooklyn bridge on sale. Real cheap.

 

[Wild_Bill_Kelso]

I really don't get your objection. I see Welkin as proof of concept that you can put merlins on a Whirlwind, with a little effort and redesign.

Whether that constitutes a version of a Whirlwind or a different but related aircraft or adaptation of the original design vs. a variant... what difference does that make? How does that invalidate the discussion?

What does it matter if it's more of a P-43 to P-47 vs a P-51A to P-51B? I have always thought of those distinctions as pretty arbitrary. A Spitfire I and a Spitfire Mk XVIII (or even say, an HF Mk IX) are pretty different aircraft to me. A Yak 7 and Yak 9 on the other hand are pretty similar.

I don't get the relevance here of the difference between adapting a Welkin or adapting a Whirlwind, but the fact that they did make the Welkin to me proves that yes indeed you could modify (and at least somewhat redesign) a Whirlwind to use merlin engines. The only question would be, how quickly could it be done and would it be worth in terms of the capability of the new aircraft (type or variant, who cares?)

 

[buffnut453]

I really don't get your objection. I see Welkin as proof of concept that you can put merlins on a Whirlwind, with a little effort and redesign.

Whether that constitutes a version of a Whirlwind or a different but related aircraft or adaptation of the original design vs. a variant... what difference does that make? How does that invalidate the discussion?

What does it matter if it's more of a P-43 to P-47 vs a P-51A to P-51B? I have always thought of those distinctions as pretty arbitrary. A Spitfire I and a Spitfire Mk XVIII (or even say, an HF Mk IX) are pretty different aircraft to me. A Yak 7 and Yak 9 on the other hand are pretty similar.

I don't get the relevance here of the difference between adapting a Welkin or adapting a Whirlwind, but the fact that they did make the Welkin to me proves that yes indeed you could modify (and at least somewhat redesign) a Whirlwind to use merlin engines. The only question would be, how quickly could it be done and would it be worth in terms of the capability of the new aircraft (type or variant, who cares?)

But the Welkin was a massive redesign....in fact, it was virtually from a blank sheet of paper. Changing one variable in an airframe will impact lots of other variables. To claim the Welkin is simply a modified Whirlwind is like saying the Tempest is a modified Hurricane.

Yes, the Welkin and Whirlwind have the same general layout and there is some familial resemblance, largely because the same design team worked on both. Similar traits can be seen with the "De Havilland fin" that was similar across the DH.88. Albatross airliner and Mosquito. However, any resemblance is purely superficial. The Welkin had a pressurized cockpit (which bolted onto the wing spar which was not a Whirlwind feature), entirely different undercarriage set-up, different flap set-up, different armament installation...all ontop of being, what, half as big again as the Whirlwind?

That's not a list of "modifications." It's an entirely new design. At least it is in my book. Your mileage may, of course, vary.

 

[Wild_Bill_Kelso]

Well I think it's clear that you'd need to do some kind of new or significantly modified wing to put merlins on a Whirlwind (or develop a new type on that basis) and some other changes done for the Welkin like changing the tail, putting the guns under the nose etc., also seem logical.

What percentage of changes constitutes a completely new type of aircraft vs. a variant is I guess another tricky subject, as i said before it seems rather arbitrary to me, but I'd also say that Welkin and Whirlwind look very similar to me. Much more so than say, Hurricane to Typhoon.

Many aircraft, especially twin engined types, had variants with a rather wide variety of engines, and some had variant or even partly interchangeable wing types.

What i was looking at was could you make some kind of fighter from the basis of the Whirlwind - due to the bottleneck on the peregrine (nobody wanted to make them and it needed further development) this means a new engine was needed. Merlin seems like a likely choice in part because they did it with the (certainly pretty similar) Welkin.

Maybe some other engine types would be possible, even a radial, though that would mean more drag. What makes the Whirlwind so interesting was it's very high low to medium altitude speed. Apparently a god bit faster than a Beaufighter (which were quite successful).

 

[Shortround6]

Welkin and Whirlwind look very similar to me.

Look closer.

Aside from the longer fuselage (about 9 ft?) and forget about the wing span.

The Welkin didn't even use a scaled up Whirlwind wing rib. It used a totally different airfoil, one that was thicker and and ran into compressibility problems (which the Whirlwind avoided by never flying high enough to run into it.

Was a Douglas A-26 a modified A-20 or was it a whole new plane that just looked a lot like an A-20?

So far what we have is that somebody at Westland (Petter?) wrote in a letter that they could put Merlins in a Whirlwind without ever explaining how (what modifications) and later they made a twin engine aircraft using Merlins that sort of looks like a Whirlwind on steroids.

This kinda, sorta looks like a modified Mustang

Now figure out how many of the wing parts are actually interchangeable. Or the vertical fin. Or..........................

This looks like a P-47

But according to one source 70% of the factory would have to be retooled to make P-47Js instead of normal P-47s.
So is it a P-47 or not?

 

[Wild_Bill_Kelso]

I don't see the Welkin as anywhere near the same kind of degree of change from a Whirlwind as a P-51 to an FJ-1. I don't think that is an honest comparison.

I mean, is a Spitfire Mk XXI the same thing as a Spitfire Mk I? How many changes were there? They put multiple different engines into a D4Y, or a Beaufighter, does that make them different planes?

Somehow both of those are D4Ys.

That's a Beaufighter

and so is that

To me the designation is fairly irrelevant, The question is, could you make it work, in time. In the case of the D4Y, the answer is ... not really. For the Beaufighter, the answer is yes indeed.

I realize changing a wing is a bigger deal than changing an engine. How long does it take to make a slightly lower aspect ratio wing for the Whirlwind?

 

[Wild_Bill_Kelso]

And if you could do it and get it into production within a year or two, you might have something. If not, there is no point.

 

[Wild_Bill_Kelso]

Look closer.

Aside from the longer fuselage (about 9 ft?) and forget about the wing span.

Many aircraft had lengthened fuselages.

The Welkin didn't even use a scaled up Whirlwind wing rib. It used a totally different airfoil, one that was thicker and and ran into compressibility problems (which the Whirlwind avoided by never flying high enough to run into it.

Was a Douglas A-26 a modified A-20 or was it a whole new plane that just looked a lot like an A-20?

I'd say an A-26 was indeed a modified A-20, it was just modified enough that they decided to give it a new designation.

So far what we have is that somebody at Westland (Petter?) wrote in a letter that they could put Merlins in a Whirlwind without ever explaining how (what modifications) and later they made a twin engine aircraft using Merlins that sort of looks like a Whirlwind on steroids.

That's good enough for me right there!

 

[Shortround6]

Somehow both of those are D4Ys.

and so is that

Because you could change one into the other. The D4Ys and Beaufighters used the same wing, the same landing gear, the same fuselage from the firewall back for the D4Y and 100% the same for the two Beaufighters. They used the same tails. All they changed was the engines.

The Welkin used not just a modified wing from the Whirlwind but not parts at all from the wing of a Whirlwind. No parts at all from the fuselage, No parts from the tail. And so on.

It was no more a Whirlwind than the F7F Tigercat was.

Or this.

 

[Wild_Bill_Kelso]

I'm all for making a mid or low altitude Vickers 432! No need to pressurize the cockpit....

 

[GrauGeist]

Westland "derived" the Welkin from the Whirlwind design. Why not?
The Whirlwind was not a bad design, so they made a bigger version with revisions.

Lockheed did the same thing with the XP-58. They took the P-38's layout and created an upscaled version. Which, by the way, also had a 70' wingspan.