Is that 200 kts just a quess on your part, the Mk XV’s were lightened airframes operating at lower weights that many other Mosquito variants, therefore in a single engine situation less power would have been needed on the remaining engine, so less rudder load.

It is an educated guess. Tail volume is not defined by the mass of the ac.

Another Welkin photo.

Also the Spruce Goose ( HK-1 ) suffered from inadequate aileron ( control ) hydraulics and was abandoned a year before completion.

Why would the extended wing mossie need more rudder power, the ailerons were the same as those on a standard wing, it just had extended tips.

Richard

Tail volume demands it.

Mossie is very difficult to fly under Vmca speed ( on one engine ) which was a very high number ( 175 kts IAS ).

http://www.pprune.org/archive/index.php/t-473377.html

Extented wings possibly needed 200 kts Vmca.

Warren Bodie, in his P-38 book, has some scathing things to say about the Welkin, and the development money spent on it – he thinks the RAF should just have bought P-38s. That said, he seems to write from a very anti-British viewpoint,s seemingly stemming from the facts surrounding the RAF cancelling their P-38 order. Nice chap to correspond with though.

Welkin was able to fly at 44 000 ft a year before P-38.

http://acepilots.com/planes/p38_lightning.html

If you are using factory drawings you’d need to 3/4 scale everything, including the pilot… or do you mean a model?

Why not build a full-size Whirlwind? Just as crazy. Can’t remember what year -1949, maybe?

I think ½ size would do too, but the wing spar is sorta in the way to make pilot fit…2/3 size could be manageable.

I think Welkin has much more aspect ratio than Whirlwind and a smaller plane could do those rolls nicely as not that much muscle is needed to deploy the ailerons.

http://hsfeatures.com/images/welkintc_1.jpg

[ATTACH=CONFIG]236624[/ATTACH]

http://hsfeatures.com/welkintc_1.htm

I declare an interest 😉 … but the Whirlwind wasn’t modest, performance wise – except for altitude. At moderate altitudes it was seriously fast for its time, and highly agile. It might be that a dislike for Westland senior staff, and Petter in particular, coloured some opinions. This disfavour would not alter what test pilots scribbled on their notepads, though. They were not Soviet 😉

To repeat (apologies to those who have heard this too often – I expect some eyes are rolling faster than a 190) the Whirlwind was designed around an end-of-the-development-line engine – that is what killed it. There was nothing modestly-performing about it. Some writers who should have known better lazily repeated this dubious non-fact many years ago, and completely failed to ask the pilots who flew it or even check the figures in date context.

Back to the Welkin, it was never designed to dogfight, any more than, say, a U2 was. It was designed to take on high-flying bombers at the edge of their own performance. Roll rate at 10,000ft was not the issue.

I am asking why wasn’t it rolling ? Due to lack of muscle of the pilot ?

From “Test Pilots” by Don Middleton.
It was criticized for its low roll rate at 10.000ft, 12-15 Seconds. It also had a lower limiting Mach number than the Mosquito.
Compressibility effects became very noticeable in a dive, letting an adversary escape easily.

Roger Rasmussen

This 15 secs roll rate sounds a bit too much. How can it be that bad ?

Wonder if the modest performance of the Westland Whirlwind sorta followed in the mindset of the onlookers at the time ?

Couldn’t have impressed the RAF though as they never formed a single unit of them, even though quite a few were built.

It is weird. This would have been a formidable weapon in the eastern front in Finland in 1944. Unfortunately England had decleared war on Finland and “officially” enemies don’t sell/lease fighters in wartime.

4 x 20 mm cannon….badass ….600+ km/h.