Managed to get a brief visit in today over at Michael Shelley’s, but it looks as though I was pipped at the post, as Michael said that he just had a phone call from someone called Andy who is restoring a Napier Lion……..

For those of you that were not privy to either conversations, I can confirm that the Lion is a mk5, and is from a Blackburn Velos, (which I believe was broken up at the Shuttleworth collection); it appears to be in very good condition.

Not a Packard 33

OK, just trying to keep this thread alive; did anyone see the Merlin 724-c that came up for auction (in Stafford) about a month ago?

Merlin 724-c engine no. 310595, was rebuilt (apparently) by Francis Machin, and was running a year ago, it was in an agricultural auction, at Garmelow manor.

Unfortunately although made aware of the sale in plenty of time, I forgot all about it; it was reserved at about £5k.

That isn’t a broad statement Stuart, you’re now into details.

In his congratulatory letter to Heinkel, RJ Mitchell only mentions the HE-70, there is no mention in his letter of ‘rib profiles’ or the NACA 2200 series, it’s doubtful he had time to evaluate them and I’m sure he had his own idea as to which airfoil section to use and plenty of time to apply it.
After all, he was an experienced aircraft designer.

Hopefully, Mr Creosote won’t get annoyed that his thread has gone so far off topic.:(

The letter sent to Ernst Heinkel from RJ Mitchell, wouldn’t have mentioned rib profiles, it was a simple letter of congratulations on, what RJ perceived as a great design; the information would have come from Siegfried Gunter, who was dispatched to the US, by Heinkel specifically, to “bone up” on US A/C designs.

Mitchell was very interested in using elektron for the skinning, of his A/C, this was I believe as a result of his visit to Germany; subsequently it was decided that the manufacture of suitable material in this country was not possible, whether it was financial or otherwise I can’t remember.

In my opinion the Spitfire was unlike any previous design, because; A, it wasn’t a flying boat, B, it wasn’t a racing seaplane, and C, it wasn’t designed to an outdated Airministry specification.

It would appear (from further investigation), that Siegried Gunter and his brother designed the HE70 betweem them, ( Siegfried must have been well thought of as a designer, as post war, the Ruskies kidnapped him, to work on their emerging Mig’s!)

And we know who to thank for the eventual design, don’t we?;)

RJ himself sent a congratulatory letter to Heinkel, after seeing their amazing aircraft at Derby, while it was their having a RR Kestrel engine fitted.
Shortly after that, he came up with his (unsurprisingly) similar F.37/34 submission, which was worlds apart from the F.7/30 and anything he’d designed previously.

We should all be grateful to Siegfried and Walter Günter, for their part in helping RJ with his design, F.37/34, Type 300 Spitfire and grateful to Mitchell for seeing the potential of the HE-70?

Why not give thanks to the entire German nation, without whom, there would’nt have been any need for the Spitfire…

I would’nt call it a hang over from previous times, every part of a new aircraft is meticolously designed and stressed etc. Most ailerons, elevators, rudders and flap structures are built up like smaller versions of wings anyway, but they are not load bearing and stressed like the main wing, and to a lesser degree tailpane and fin structures. There wasn’t always the need to metal clad the moving parts, so if it can be done in fabric and save weight and complexity, plus easier to make non stressed repairs, it was a good option.

When aircraft are tested it is not just in a straight line, the full handling envelope is tested before certification can be given.

Yes you are right, silly me for thinking that there would be any significant loading on an aileron, rudder, or an elevator; probably why the Spitfire used fabric control surfaces throughout the various mks……. oh hang on, didn’t they change to metal elevators and ailerons……

Is it not the case , that the Merlin, (and Griffon), are limited to around 3000 rpm, purely because beyond that engine speed, the propellor fails to deliver anymore thrust; hydraplane racers do use Griffons, and do blow them to pieces, and in theory, there is no reason why any engine can’t be made to run at high rpm, for a short while at any rate.

That would have been the one I had, it went to Norfolk, but was on ebay either last year, or earlier this year, and sold quite cheaply; still in this country I think.

Having spoken to the chap in question, it appears that Michael Shelley does have a Napier Lion in his collection; I am in the process of trying to arrange a visit, and will let you know, if this comes about.