Supermarine Spiteful and Seafang

[Erfolg]

Colin, why not get it flying, then the finishing and new spinner can come along as a continuing programme of updates.

The Spiteful is certainly one of the Spitfire types I have liked the look of. The model certainly looks good.

I recently saw a picture of a clipped wing Spitfire which looked very suitable for modeling, the pointy wing tips having gone, to a plan form very similar to a Seafury, Much more practical planform without a lot of washout.

In your case i am waiting to read about a successful flight and then the planned changes.

[Colin Leighfield]

That's the plan Erfolg, I've been frustrated by what seemed to be intransigent problems with the motor and spinner combination.

The clipped wing spitfire is exactly that, the wing-tips were always removable and all they did was to replace them with a streamlined fairing. Otherwise the wing is identical to a standard Spitfire and the wash-out the same, based on an incidence of +2 at the root and -0.5 at the tip. The 20 series wing was different because it was re-engineered to be stiffer with a theoretical aileron reversal speed of 850 mph, way beyond the mach limit of the plane. However, the structural changes and slight widening of the ailerons changed the shape of the tip and it was no longer removable. Aerodynamically it was unaltered, section still NACA2200 and wash-out 2.5 degrees.

Ironically, although the Spiteful wing was developed by the National Physical Laboratory using their supersonic wind-tunnel, it proved to have a Mach limit of 0.82, same as the P51, whereas a standard Spitfire IX could be dived to Mach .85 and Farnborough took a MkXI up to Mach 0.92. The Spiteful had a "high speed" wing section (!) and no wash-out, which is probably why the main problem with it was dodgy low-speed handling. These are the reasons I've been interested in the Spiteful. I shouldn't have allowed myself to be diverted by the Depron Barnstormer, which taught me how to use Depron but proved that the Barmstormer was probably the last design to choose for the exercise!

Edited By Colin Leighfield on 09/09/2014 12:58:56

[Erfolg]

Colin

I was principally referring to the impact on the need for washout on a models wing.

Although in the full sized aircraft there will have been a reduction in washout, albeit small.

With respect to the model, it was bringing the tip to root ratio to something that looked to be about 0.5. At a practical level, the tip losses would be greater, at low speed, although the onset of the stall, even with a reduced washout, should be more benign, rather than the sudden separation, which moves rapidly from tip to root.

It is one of the areas I have empirically investigated and am pretty sure for the same aircraft, with differing wing shapes, that parallel chord, low aspect ratio wing, is far more friendly than the same area, where the wing is higher aspect ratio, with pointy type wing tips.

Another aspect which i did not really investigate, what the difference in stalling speed was. The main reason I could not convince myself that I could actually measure the speed. More importantly to me, it was the difference in the stall which ensured that when landing, with the pointy wing I had to keep the speed up, as the stall was impressively fast, in its initiation. On the other hand my chunky wing, pretty much just slowly stalled ahead, which suits me just fine.

I was tempted to try and see what the impact on top speed would be, although, I personally did not think it would matter, or be measured by me. Probably the main reason being, that I was told on a project I worked on, that tip losses at speed, were not the problem. When manoeuvring there was more concern that these were often power issues, weight and other issues, which had to be balanced.

I missed an opportunity with the PC at Greeacres, to compare my 10% wing with the 5% std winged PC.

With respect to the Spiteful, I would still be tempted to build in washout.

My Me 109 is probably a similar tip to root ratio, and proved to be a bit of a handful with no washout. I retrospectively built some in by removing the top skin, twisting, then re-skinning. Handles much better now. If you have an issue, you could always try putting some washout in.

 

 

Edited By Erfolg on 09/09/2014 14:19:36

[Colin Leighfield]

Erfolg, there's plenty of evidence for no explained reason that flat-plate wings don't tip stall. Years ago when Tony Nihuis did his little electric Spitfire with a sheet wing he didn't use wash-out and from what I saw of them, they didn't need it. It is certainly Nigel Hawes' experience that it is the case. So there's no wash-out in this one. Last year in the Tucano exercise Nigel altered the design to feature the scale highly-tapered wing shape and said that it didn't tip-stall. If I was producing a built-up wing with any taper or elliptical element, I wouldn't think twice about it and the 317 has 3 degrees designed in for that reason. I think we've exchanged on this subject before and I'm guessing that because the constant wing thickness effectively increases the thickness/chord ratio markedly at the tip, it has similar effect to wash-out but in a different way, and the tip similarly stalls after the root.

This project, in spite of the unintendedly long gestation period, may have a short flying life, the first hand-launch might be the end of it. I will be asking for help from some of the top-notch blokes we've got in SCRCAC at Fradley however in the hope that won't be the case. If it flies as well as the Tucano, I will be more than pleased. Hopefully it will survive and if it does I'll see if I can tidy up the plan in case anyone else wants to have a go.

[Graeme Poke]

Colin that looks sooo good. Well done. The flight experience will interesting. I must build one of these. Good luck.

Cheers Graeme

[Colin Leighfield]

Thanks Graeme. Won't be long now.

[Colin Leighfield]

Finishing stages at last. Dark Sea Grey top coat applied, 17g glass cloth and Ezekote to nose underside and radiators to provide protection for sliding on the grass. Duck egg blue top coat on underside next, then guns and stickers. Hope to have it finished this week.

[Tony Bennett]

nice.

[Colin Leighfield]

Thanks Tony, it's another one of those that has got complicated for the daftest of reasons, but it's looking as if it will have been worth it. I've spent more time messing with motors and spinners than I did building it, which was quite simple. Clearly I'm lacking something, like perhaps a brain.

[john stones 1 - Moderator]

You're lacking some roundels Colin looks very good

John

[Colin Leighfield]

John, I've got the full set of markings for VB895, (courtesy of Tim at Model Markings), one of two Seafang F32s built but the only one to fly, sadly. One more lick of paint and they'll be on, although I'm snookered for a couple of days now because of a family funeral in Suffolk tomorrow.

[Colin Leighfield]

Painting done, although a bit of touching up required on top. Couldn't resist putting on the lower wing roundels, although I want to draw in panel lines, undercarriage doors etc. before I put the big serial numbers on.Looking at this page on volume 7 of Aircraft of the Fighting Powers 1947 shows it fitted with the later short barrelled Hispano cannons, as fitted to the Attacker, so I am going to do those and avoid the usual problem of guns breaking off that you get with the longer version.

[Colin Leighfield]

All that's left now is to fit the rest of the decals, position the battery for cg and set the control throws. Still unsure about the short barrelled Hispanos, most of the photos show VB895 with the longer barrelled guns and also the production Attackers have the same. However the picture from Aircraft of the Fighting Powers shows it with the short gun fairings and also photos of the E10/44 "Jet Spiteful" TS409 and the prototype Attacker TS413 show them with the short barrelled guns as well. Therefore it was definitely right for a while.

[john stones 1 - Moderator]

Looks good to me Colin and as you said, they are prone to getting broken anyway, it looks like good windy day model to me

John

[Colin Leighfield]

We'll soon find out, I think I'll be looking for a better test pilot than me for the maiden though! Debating whether to risk the under-arm launch, it's got enough poke to go vertical, or to have a go at making a trolley/bogie, I've never done one but those I've seen generally seem to work well, perhaps that would be less nerve-wracking!

[The Wright Stuff]

Wow. And wow again. Colin, it looks absolutely fabulous in the Dark Sea Grey.

Ever since my first Airfix kit as a child, putting the roundels on models has always been my favourite bit! There's something so disproportionately satisfying about sticking them on, isn't there?

[Colin Leighfield]

I generally stick them on too soon and make a mess, not this time though. Can't touch this now until Sunday because I'm away until Saturday night. Frustrating!

[Simon Chaddock]

Colin

It certainly looks the part.

Static its ever so short of propellers - 2 instead of 6!

There is a lot to be said for the standard Navy colour scheme - its simple.

Cant wait to hear about its maiden.

[Danny Fenton]

Wow fantastic Colin really nice, but don't blink on an overcast day or she will be over the horizon

Cheers

Danny

[Colin Leighfield]

You're right Simon! I like contra-props too, perhaps a bit too much to bite off just yet though! I agree with you about the navy colour scheme, I liked it even more when they extended the duck egg blue up the fuselage sides, which the Seafang certainly would have had if it had gone into service.

Thanks Danny, methinks you might be right.

[Colin Leighfield]

Getting to the tidying up stages now. I want to paint the spinner black, aluminium isn't perfect for painting but the linished finish will help adhesion a bit.

[The Wright Stuff]

Lovely to see some photos in its natural grass habitat! The clean lines of the wings look great: no servos and horns cluttered everywhere.

Almost there: black spinner and yellow prop tips? good luck with the maiden!

[Colin Leighfield]

Strip ailerons wouldn't work with this wing shape and the wing is too thin for the servos to be easily buried, so I put them inside the underwing radiators.

[Mark Kettle 1]

Boy that's nice, excellent Colin.

[Mark Kettle 1]

Boy that's nice, excellent Colin.