Jez Saunders

Just learnt of Mr Geoffrey Wellum passing on this forum, read " First Light " a while ago and it made a big impression on me . A real hero and his story must represent what the "few" we owe our freedom today went through emotionally and physically in those times. RIP Mr. Wellum and thank you.

And to keep things going I will throw the Mustang into the discussion, gave a lot of support to bomber crews and did a lot of damage to Hitlers war machine, no one aircraft won ww2 but the Spitfire was one of the most beautiful aircaft in its appearance ,performance and sound.

Anything you say about this incredible guy can not do justice to his achievements and how he overcame his disability defying all the odds. If there is a better place I hope he is able to go on in his quest for more understand of the Universe . When asked what confused him most in the Universe he replied " women ". RIP Stephen.

If nothing else this thread is improving my maths !

As supertigrefan says ? Also which is the best online tutorial ?

Thanks David, not really into the maths but going to your models of equal wing loading but different inertia characteristics problem it most be the difference in mass ? Perhaps the mouse and elephant example could be applied here ?

Going straight to structural integrity we are lucky here that we can get away with a "weaker" structure, eg a mouse has speed and agility to get away from a predator , if an elephant had the same scale speed and agility it would break it's neck at the first evasive manover. .? That is unless someone know different ?

Thanks Mike, I stand corrected, was watching the brit awards while caculating ! So it does work out close to scale ?

Put one of those cheap low battery warning indicators on.

So with the above doubling radius idea increases volume eight fold I arrived at 139 kg for our 1/6 scale spitfire that weighed 3022kg 1:1. This is also far to heavy in the real world so our model aircraft weighing say 12kg has a significant advantage to fly. This has probably already been said but I had to to think about it my way I was bored !☺ Edited By Jez Saunders on 21/02/2018 21:13:55

Pardon my ignorance but coming at this on different level ( because I can't get my head around some of the mathes) scale speed should be a fairly straight forward conversion , 360 mph would convert to 60 mph for a 1/6 scale model Spitfire for eg. Weight is completely different equation, eg Spit again had a take off weight of around 3000 kg and our 1/6 scale Spit would weigh 500 kg which is obviously wrong but I do understand this because volume is not linear eg a sphere with a radius of 5 units has 8 times the volume at a radius 10 units. My point is in my mind scale speed should be easy to measure?

Just give me a little time to catch up !!!!

And a model size aircraft probably is easier to get into a flying condition than a full size aircraft, Reynolds effect etc. Maybe ?

I was wondering if the Wright brothers used for formula in their creation of the Wright flier ? Some time later, a few decades, R J Mitchell designed the Spitfire who would certainly have used it, the Spitfire is aesthetically pleasing to the eye , but I read somewhere that the wing cord was a thick as it was because the at the time of design glycol had not been invented and the wings were to condense steam from the heat of the engine for cooling, some of its flight performance potential was luck, also it looked right so it had to work !

David, you obviously understand the subject of aerodynamics well , I follow some of what you say and have gained a little more understanding of the subject. Thank you. I don't think you are" being clever " . Discussion and debate are an essential part of learning. There should be no such thing as a stupid question and that should be a strength of this forum ( and other's ) difference of opinion is what leeds to ideas and understanding. There should be more debate like this, I am no intellectual but I do enjoy this type of discussion and it should be encouraged !😃