Rolls Royce Mustang FTB's

[Tophe]

Congratulations!
And thanks for the 8mm longer fuselage story. I will work on it Inside my Mustang topic. Thanks again!

[kitnut617]

Thanks guys,

Harold, I like the mid-engine arrangement too, I bought a couple of those CMK Wyvern TF.1's a while ago with the intention of converting one of them to the earlier mid-engine arrangement that it was originally designed as.

Tophe, strangely Unicraft includes a 3-View 1/72 drawing with the conversion set, the conversion parts don't match it because the drawing is more correct. IIRC, it's a Justo Miranda drawing

[NARSES2]

Thanks for the info on the X Robert 

[kitnut617]

No worries Chris,

Some additional information. When RR installed the Merlin, they used exactly the same engine/prop combination as the latest mark Spitfire at the time had. They were amazed to find during flight testing, the Mustang was almost 30 mph faster than the Spitfire in every flight scenario they put it in. They put it down to the laminar wing which, IMHO, led to a lot of wasted time chasing down the laminar flow idea. Case in point is the Spitfire/Spiteful, when Supermarine designed their laminar flow wing for the Spiteful, it was only 3 mph better than the latest mark Spifire (a Mk.21) when the two aircraft were tested. One of the reasons the Spiteful didn't progress after the war.  BTW, the Mk.21 and other marks afterwards did not have a laminar flow wing, they had what was referred to as a 'speed wing'. The so-called Spitfire Mk.23 had a modified Mk.21 wing which was supposed to 'simulate' a laminar flow wing without it being one. It proved to be no better than the Mk.21 wing.

[wuzak]

The Spiteful XIV with Griffon 69 had a maximum speed of 481mph @ 26,000ft (+18psi boost), 483mph @ 21,000ft (+25psi boost) and 436mph @ 11,400ft (+18psi boost).

The Spitfire 24 with Griffon 85 had a maximum speed of 454mph @ 26,000ft, 420mph @ 12,000ft.

Whether the extra speed came from the wing, improved radiators, or other areas of improvement, is debatable.

[kitnut617]

Had to re-read my Morgan/Shacklady book wusak, you're right.  What I've read was when testing the first Spiteful NN660, it wasn't any better than a Spitfire

[wuzak]

Had to re-read my Morgan/Shacklady book wusak, you're right.  What I've read was when testing the first Spiteful NN660, it wasn't any better than a Spitfire

I believe that the Spiteful didn't handle as well as the Spitfire 20-series. Which, in turn, didn't handle as well as the earlier Spitfires.

Well, at least Alex Henshaw wasn't a fan of the 20-series Spitfires, much preferring the earlier Merlin Spitfires (I am not sure, but it seems his role as factory tester saw him going from Mk IX to 21, and that he didn't try the XII/XIV/XVIII).

[Tophe]

I tried to draw the different sources, not perfectly just trying...
My goal is not to cheer the true one(s) but I love changes in any direction. Thanks again.

[KJ_Lesnick]

kitnut617

The mid-engine arrangement would allow for various engines of size and weight to be tested without having a serious cg problem every time a different engine got installed.

I could never understand the reason up to this point.

[Weaver]

Images posted on Twitter here: https://twitter.com/TrevClark1958/status/1286753019078619137?s=20






Note that this cutaway should be taken with a grain of salt. IIRC, the creator is a what-iffer who modifies cutaways:

[kitnut617]

Seeing you post here Harold brought me straight to it, then realized with the PB debacle my photos had disappeared. I've updated my first four posts with the photos again.

The photos you have posted are all in the Rolls Royce Heritage Trust book, 'Rolls Royce and the Mustang' by David Birch (who unfortunately has died last year) Apparently, the 'mock-up' was totally built out of aluminum as if it was a prototype.

[Weaver]

Nice one!