Tim's Spitfire 21 - COMPLETED

[theplasticsurgeon]

Introducing my Aeroteam 1/72 Spitfire 21, costing £4 from IPMS Gloucester model show in 2019.

Thanks to Patrice for adjudicating the 25% rule,  some construction having taken place.

Instructions,

 

All but the first  Spitfire 21s, were built at Swindon, on the site now occupied by Honda.

There is an Archery club there called Supermarine,  at which I've competed in a few tournaments.

Their emblem is a 6-blade, contra-rotating propellor, which would have been fitted to a few of their Spitfires.

Mine will be a 5-blade prop,  I used the kit's 6-blade prop on my KUTA Spitfire PR19

The Supermarine clubhouse has pictures on the walls of Spitfires, in celebration of their heritage.

 

[theplasticsurgeon]

To be built as this Spitfire LA226, displayed at Swindon for a long time.

f

The long haired young man is my friend Barry, inspecting the Spitfire. 

Probably during the 1970s, when Barry was a speedway rider - hence the racing fuzz.

 

Barry and I frequently work the Jet Age cafe together, terming ourselves 'The Dream Team'.

 

 

[GREG DESTEC]

Barry?? You sure it's not Billy (Connely)

[alt-92]

So I wasn't the only one doing a double take!

[Mr T]

I will watch this with interest as i have the kit, as an early Eduard rebox with added bits, very tempting

[theplasticsurgeon]

So now for some initial thoughts about this build.

The fuselage is closed up before cockpit installation - which could be an issue.

And the prop isn't installed yet, another challenge.  

I've got a leftover prop from my Airfix PR19 - which I'm more inclined to use for this build.

Additionally this kit offers etch-brass parts, an instrument panel decal,

and a vac canopy - and I've got a leftover Pavla canopy.

Laminar flow wing, the Spitfire21 is a high-back partner for the low-back 22:

 

And Barry hasn't really changed or grown-up since that photo. 

Just as long hair and as much facial fuzz - but grey now.

Working the Jet Age cafe with him is a pantomime every time.  Stay safe Barry.

[theplasticsurgeon]

Opening day progress.

 

Firstly, that's the Airfix prop and spinner, heat smashed on - thus avoiding re-opening the cowling.

And it still spins!

Those are the cockpit bits about to be installed.  Instrument panel is a card print this time, glued in place.

All the bulkheads installed and fixed, then the wings.

Tailfeathers.

I really think this kit is the most rewarding of the 3 I'm building. 

 

[theplasticsurgeon]

Bank Holiday Monday (like I noticed that today) - seams treated with Tippex.

In the company of my Airfix Spitfire 22,  with a similar laminar flow wing,

I've got to say the AeroTeam is a lot heavier (thicker plastic).

[theplasticsurgeon]

Bit of a slow day, but I painted the Sky band and spinner,  accompanied by my Airfix Spitfire 22, 

[theplasticsurgeon]

Airbrushed Humbrol 64 underside.

[theplasticsurgeon]

Canopy fitted, in this case leftover parts from the Italeri build.

[PeterB]

Hi Tim,

 

I know that the Mk 21 introduced a modified wing with longer ailereons (I think, or maybe just moved outwards a bit), which changed the shape of the tip, but I did not realise it was a laminar flow one - I thought that did not happen until the Spiteful, or maybe the proposed Mk 23 which had a change in wing leading edge or something, but was never built.

 

Whatever, all 3 builds are looking good.

 

Cheers

 

Pete 

Edited April 16, 2020 by PeterB

[Troy Smith]

31 minutes ago, PeterB said:

I know that the Mk 21 introduced a modified wing with longer ailereons (I think, or maybe just moved outwards a bit), which changed the shape of the tip, but I did not realise it was a laminar flow one - I thought that did not happen until the Spiteful, or maybe the proposed Mk 23 which had a change in wing leading edge or something, but was never built.

It doesn't AFAIK.  

The 20 series new wing is actually the same outline shape as the old one,  there was a test version of PP139 which has extended wing tips.  The tips settled on are the extended ones cropped.

see here https://www.key.aero/forum/historic-aviation/88886-spitfire-mk21

Laminar flow turned out to be a an impractical idea, and some wings described as such are not in fact (eg the Mustang)

The new wing may have a revised aerofoil section?  Anyway the 20 series  wing was much more successful than expected, part of the reason the Spitfeful/Seafang never got developed. These have been discussed in the WW2 section on occasion. 

 

apologies for the digression @theplasticsurgeon  hope of interest.

[Graham Boak]

The XX series wing was not laminar flow, it had the same section as previous.  Also the same planform as the extended tip Spitfires, minus a bit at the tip itself.  It was different inside, being much stronger and stiffer in torsion because of the history of wing distortion in high speed in dives.  (Look for a history of aeroelasticity, if you feel strong and have a grounding in aerodynamics and structures.  Look for divergence speeds and reversal speeds.)  It also had a taller and stronger undercarriage, mounted further apart.  As suggested above, it had larger ailerons, going from a Frise design (longer chord underneath) to a plain hinge.

 

The Mk.23 did have a leading edge drooped some 2 degs (or a bit more?) but handling proved a bit sharp so this was abandoned.  (Not sure whether this was actually tried on a Mk,.VIII, but suspect no Mk.23 was ever built.)

 

I have seen it suggested that the Mk.21 had the same propeller as the Mk.XIV, rather than the larger diameter one on the later variants, but if so I don't understand why.  I suspect this was someone leaping to the assumption. However if you have used the Airfix 1/72 kit spinner rather than its Freighdog replacement, that's the one for the Mk.XIV anyway.

[theplasticsurgeon]

Airbrushed Humbrol 106 Ocean Grey

And it's time for a

[PeterB]

6 hours ago, Graham Boak said:

The XX series wing was not laminar flow, it had the same section as previous.  Also the same planform as the extended tip Spitfires, minus a bit at the tip itself.  It was different inside, being much stronger and stiffer in torsion because of the history of wing distortion in high speed in dives.  (Look for a history of aeroelasticity, if you feel strong and have a grounding in aerodynamics and structures.  Look for divergence speeds and reversal speeds.)  It also had a taller and stronger undercarriage, mounted further apart.  As suggested above, it had larger ailerons, going from a Frise design (longer chord underneath) to a plain hinge.

 

The Mk.23 did have a leading edge drooped some 2 degs (or a bit more?) but handling proved a bit sharp so this was abandoned.  (Not sure whether this was actually tried on a Mk,.VIII, but suspect no Mk.23 was ever built.)

 

I have seen it suggested that the Mk.21 had the same propeller as the Mk.XIV, rather than the larger diameter one on the later variants, but if so I don't understand why.  I suspect this was someone leaping to the assumption. However if you have used the Airfix 1/72 kit spinner rather than its Freighdog replacement, that's the one for the Mk.XIV anyway.

With apologies for the intrusion Tim, 

Graham - Price confirms that the proposed Mk 23 wing was tested on a Mk VIII JG204 he says "...externally similar to the Mk 22 but with a wing of revised cross section with the leading edge raised by about an inch and many of the characteristics of the laminar flow wing designed for the Spiteful", It seems that the performance was not as good as expected and there were handling problems so the Mk 23 was never produced. I think it was Eric Brown who said in one of his books that early laminar flow wings were very easily messed up, even by accumulations of dead flies etc. which were enough to disrupt the airflow - sounds a bit like the B-2 bomber where the slightest imperfection screws up the stealth characteristics.

 

As to the prop, he says that early Mk 21 used the canopy and tail of the Mk XIV but no mention of using the prop. Instead he says that the extra length of the gear legs allowed the use of a 5 Bladed Rotol of 11' in diameter, 7" greater than that on the Mk XIV. A few late ones were fitted with 3 bladed contraprops and apparently had much improved handling, but very few if any entered service it seems - Quill says that the prop mechanism was heavy, expensive and initially unreliable,

 

I will leave you to get on with your thread Tim,

 

Cheers

 

Pete

Edited April 16, 2020 by PeterB

[theplasticsurgeon]

All preped for camo airbrushing tomorrow.

[gingerbob]

Is there a gap in the leading edge near the root, or is that just a trick of the photo?

 

I only just got here, and as I was reading through I was worried about the cockpit- especially because my first glance of the instructions made me think, "Boy, that drawing could make an eager lad glue up the big bits and then realize all that stuff top left was supposed to be put inside first!"  But apparently it can be done.

 

bob

[theplasticsurgeon]

9 hours ago, gingerbob said:

Is there a gap in the leading edge near the root, or is that just a trick of the photo?

I think that's a trick, but I'll check before airbrushing.

9 hours ago, gingerbob said:

I only just got here, and as I was reading through I was worried about the cockpit- especially because my first glance of the instructions made me think, "Boy, that drawing could make an eager lad glue up the big bits and then realize all that stuff top left was supposed to be put inside first!"  But apparently it can be done.

The prop isn't as tight as I'd like it to be.

[theplasticsurgeon]

Airbrushed Humbrol 163 Green.

and unmasked.

 

[gingerbob]

Is it just coincidence, or are you partly to blame for my recent musings about a Mk.21 conversion?

 

Lookin' sharp- and that weird leading edge illusion has disappeared.

[theplasticsurgeon]

Decals.

[theplasticsurgeon]

Yellow leading edges.

[stevehnz]

Nice that Tim, we may have seen it a thousand times before but a Spitfire (especially a Griffon engined one) in those colours takes a heap of beating. IMHO of course.

Steve.

[theplasticsurgeon]

Canopy framed, cannons fitted, also the radiators underneath - I'll show those when undercarriage goes on.