Thank you, Momoe.
The Welkin was of course designed to counter a contemporary threat.
By the time it had been developed to a usefulness, that particular threat had waned.
The exigencies of war, eh?

I must say, though, that both the DH Hornet and the Grumman Tigercat, (IMHO), rate as the most visually and aurally stimulating
piston twins ever designed.
So there.

Interesting posts and thanks to oxenos for the answer to my original question.

It seems the Welkin was quite a large aircraft; wingspan of 70' compared with the Whirlwind's 46' and the Mosquito's 55'. I guess that span/aspect ratio was needed for its high-altitude role.

Eclipse of Whirlwind, rise of Spitfire were not determined by quality as perceived during 1939. It was industrial logic.

Whirlwind protoype contract 11/2/37. (Westland's near-bankruptcy, 10/35 had been rescued by 9/36 order for 169 Lysanders; again: ) 7/38 Ministers encouraged mariner John Brown and sparks AEI to inject equity: Spitfire wing ribs were from Westland. Reward was order for 200 Whirlwinds, early-1939, 200 more later 1939: cannon-armed escorts for RAF Medium Bombers vaulting over the Maginot and Siegfried Lines, beyond Hurri/Spit range (UK did not fund a small conscript Expeditionary Force for France until 23/4/39, intended for 1941).

Lord Nuffield was underway late-1938 building Castle Bromwich Aircraft Factory for Battles, changed early-1939 to Whirlwind, to which Spitfire Mk.II was added, 4/39...or so Air Ministry thought: (Spitfire's) "future was assured (due to) stubbornness of 1 man (N, insisting) on producing (all of all) 1,000 (at CBAF, so Whirlwind was) squeezed out”’ A.M.memo, 11/7/39, in E.B.Morgan/E.Shacklady, Spitfire, Key, 1987, P51: any colour you like so long as it's black. Nuffield wanted mass/same-same for his auto-production process: Spit easier than Whirlwind.

Add in Merlin finding so many berths; add in RR Experimental resources being dissipated over too many Projects; add in RR diversion to Supervising Merlin shadow production in quantities unseen since 1917...add in orphan Peregrine...and Whirlwind production slipped down the priorities list. It wasn't technical complexity, nor was it MG vs. cannon, that caused priority to Hurricane/Spitfire: it was the evident need as 1939 became 1940 for kit, anykit, even dodgy US types, NOW!

http://i1047.photobucket.com/albums/...lwind_10-2.jpg

http://i1047.photobucket.com/albums/...0a%20stall.jpg

I seem to recall that the Whirlwind was not a good fighter to have to bail out of due to the high tail getting in the way? I'm sure I read that quite a few pilots ended up with injuries from hitting the tailplane as they exited their stricken aeroplanes.

Those air-to-air pictures. Just look at the visibility that the pilot had.

A few of these in the Battle of Britain would have been interesting. 4 20mm cannon would have been formidable fire power. IIRC I read about one of the few cannon armed Spitfires around the time of Dunkirk, pilot pressed the trigger and almost in an instant his windscreen was completely red!

That exhaust system was on the first prototype, and only retained for a very short period of time, after which the system was modified to a shrouded ejector exhaust as seen on many Merlin installations. An impetus to the change was probably an incident that took place on 10 June 1939, where shortly after take off the aircraft rolled viciously to the right. The right aileron had gone to an uncommanded full up deflection which the test pilot, Harald Penrose, was able to control by full opposite aileron. A judicious landing was then made without any effective aileron control. The right engine exhaust duct and insulation had failed allowing hot gas to burn through the aileron push rod.

As for Petter designs and their flaws, remember he did design the Canberra, and Westlands allowed him to take the design with him when he left their employ.For bail out the tail is in the ideal place, high and out of the way. Mythology has the P-38 tailplane being an impediment to bail out also, which was not the case.The Exactor system was used on the throttles, mixture, prop pitch, undercarriage, flap, wheel brakes and fuel cocks.

P7048 (evansb's photograph) was one of the surviving Whirlwinds. It achieved 123.25 operational hours and was registered by Westland post-war as G-AGOI. Scrapped 1951. (per the Bowater book).

The canopy on the Whirlwind apparently was un-jettisonable so in order to vacate the cockpit the pilot had to try to wind the canopy rearwards. This could be difficult/impossible if the canopy rails had sustained damage.:eek:

And the Lysander with its lethal combined automatic slat/flap system. The associated [sudden, unannounced] nose-down pitch trim change of which was bad enough, but when the Westlands Chief Test Pilot took Petter up to demonstrate what it did for an aborted landing* he found the experience so frightening it had a profound effect on him - he never flew in one of his own designs again.

PDR

* With the aeroplane trimmed for approach the sudden application of power killed the descent, but once the aeroplane accelerated ant the AoA dropped the slats/flaps retracted, leaving the aeroplane with a massive nose-up trim that needed a huge stick force (>100lbs) to prevent the aeroplane pitching to the vertical and then falling out of the sky. This characteristic was especially appreciated by those pilots who, when dropping SOE agents into small fields on moonless nights and the suddenly discovering it was the wrong field or it was over-run with german troops...

Petter found a simple way of sorting out the trim change of his later Gnat when the undercarriage was selected down, moving the CG forward...:hmm:

A piece of bike chain connected the main undercarriage to the longitudinal control system, adding about 3° nose-up tailplane incidence as the wheels came down.

And the Lysander with its lethal combined automatic slat/flap system.
Of course the original idea was that the automatic flap/slat interconnect cancelled out the pitch change near the stall. I seem to recall that the system could be locked.

AIUI (I haven't flown a lysander) it could be locked *up* but not *down*, so the locking is not much use for the covert insertion ops.

PDR

Any updates on Peregrine field finds or castings in storage...however unlikely?