Stalling - why is it so dangerous?

[Former Member]

[This posting has been removed]

[Gemma Jane]

Please sir he started it

 

Fact is Tony, John likes to go into these things a little deeper than most people. It is his thread after all. I would not spout all this technical jargon for the benefit of modellers in general.

 

Mostly because it is not needed to enjoy the hobby anymore than it is needed to enjoy and excel at the art of flying.

 

I simply feel you jumped in on the thread at the wrong time with the wrong attitude. Not upset, just indignant that you attempted to undermine the discussion by claiming it was incorrect and the work of amateurs. I don't see the content of this forum has to only exist at  one level.

 

I get the feeling half my modelling projects I've blogged on here leave people wondering if I have a clue what I'm doing. To me the only thing to prove on here is that I can model and also design models. Quite enough for me.

 

Perhaps one might have avoided the issue by starting a new thread putting forward your own views.

 

Of course you were also more than a little direct regarding my thread on the original Martin Bedding's article. It seems you are stuck in a single view, on the one hand saying that I can't explain things, on the other saying I wasn't aggressive enough regarding the article.

 

Get things in perspective Tony, this is a forum about toy aeroplanes.

 

Sorry if I have not explained myself clearly there, I did my best.

[Tim Mackey]

I actually think that Gemma does a pretty good job of explaining things in her posts....for an engineer.

Seriously though...the thread about how she is building a vac forming machine for example  is well illustrated and simple to follow so far.

As Phil has already said...please keep it friendly folks, as the last thing I want to do is neck posts.

Edited By Timbo - Moderator on 14/07/2009 10:37:37

[Tony Jones]

Hi Gemma

 

OK, disregard my last post which crossed with yours of today  10:21:32. Actually, with luck, it won't appear as it seems to have disappeared in to a black hole.

 

I PM'd you because I thought we could have an amicable discussion (not argument) without cluttering up this forum with discussions of windshear. Sorry that you didn't reply. 

 

Also sorry you feel I 'jumped in on the thread at the wrong time with the wrong attitude'. I must go and check on what the 'correct' attitude is. I was not attempting to UNDERMINE the discussion by claiming it was incorrect and the work of amateurs,  but, as far as I can see, most of the contributors, excluding yourself, are indeed just that.

 

For my sins I have had long experience of technical forums and the big problem has always been (and probably always will be) that enthusiastic amateurs are often mis- or only partly informed. And such people often put forward their opinions in such a robust and authoritive way that  they appear to be true.  I was just trying to point out that there are a number of excellent books on aerodynamics and the principles of flight, and anyone keen to get things right would be better of reading one of those.

 

Sorry to hear that you are unimpressed with Kermode's Flight Without Formulae. Lots of people have - and still do. The author himself admits that some of his 'cause and effect ' descriptions are not STRICTLY accurate in the scientific sense but are the best he can do without resorting to formulae - which is the whole point of the book.

 

I will now stick my neck out and recommend another: Basic Aeronautics for Modellers by Alistair Sutherland. Published by Traplet. Just my opinion, of course.

 

Best wishes

Tony

[ken anderson.]

game set and match to gemma/tony..........thing is like gemma say's-this is a forum about 'toy aeroplanes'.........
the past week iv'e had mishap's with two of my squadron-if mine had full size pilot's in they would have bailed out long ago ......

i still say yet that we can't really equate what we're doing with our toy's to the full sizer's-if that were the case imagine the prob's grant from 'foamyjet's ' is going to face with his new airbus........model's/toy's fly far to fast compared to full size..pull tremendous G force's..that would destroy a the real thing.....................this post is from an uneducated in aerodynamic's aero modeller...whose mission for the past 40+year's has been to defy gravity with bit's of wood with engine's stuck on it--shortly to be away out for the next episode...............................my view on thing's not right or wrong.......

 

        ken anderson...............

 

ps see my last post in the 'cafe' for a real challenge to fly........

[Tony Jones]

Hi Ken

 

I agree that a comprehensive knowledge of aerodynamics is unnecessary for model flying, and that our models are often very different to the real thing. But some knowledge is very useful.  IMHO, the tip to pick up a dropped wing during the roundout with rudder rather than aileron is a good example. It helps to understand why this works - as has been explained nicely on this thread.

 

I was tempted into this discussion because I am surprised at how many model pilots don't bother to become familiar with their aircrafts' low speed handling. When I'm testing a model for the first time, I will always climb to '3 mistakes high' and do some stalls. This helps me plan the approach and landing.  For example, if the model has a very sharp stall with associated wing drop in one particular direction I will add 5mph for safety on the approach and try and wheel it on rather than go for a 3-pointer. If on the other hand the stall is benign and mushy with wings level, that gives me confidence to try for a nice slow touch down.

 

Similarly, an appreciation of the way stalling speed increases markedly in turns is useful in reminding one to have a decent margin during the turn on to finals and if you are forced into a low/slow turn to add power and handle the stick VERY gently.

 

Best  wishes

Tony

[John Cole]

I recommend "model aircraft aerodynamics" by martin simons.  The fourth edition is dated 1999, so it doesn't have data on the latest wing sections (more recent ones are easily found on e.g. michael selig's site / university of illinois).

 

Selig aerofoil data

The first edition came out in 1978, and as I recall martin used to write for rcm&e about that time.  It's slightly mathematical in the sense that it quotes formulae but I would guess it's easy to follow without going into the maths; just read the text and study the graphs.  It is perhaps a bit sailplane-focussed, but then perhaps that's the area where aerodynamics is most important.

[Martin Harris - Moderator]

Posted by Tony Jones on 13/07/2009 18:14:56:
To those who find this debate 'interesting' , may I point out that amateur forums like this are breeding grounds for partially informed and badly informed opinions expressed by people who often don't know what they are talking about.

 

 A rather sweeping comment if I may say so - I certainly don't claim any professional expertise along with the majority of enthusiasts on the forum.  However, contributors like Gemma who are qualified in the subject of aerodynamics and others who have their own areas of expertise often step in when we amateurs stray from the path a little, which I feel only helps to educate both the poster and those who are following the debates.

 

Certainly, there is a wealth of information around in written form but many people are intimidated by theory books and prefer to ask people who may be able to explain complex subjects in a focussed way without going too deeply into the minutiae of the subject.

[Boots]

I have dived to the ground or corkscrewed down a few times on last turn before final approach.

flying low, flying slow, turning a bit too sharply to line up for correct approach

I had never considered the geometry of turning , course it is obvious now  john cole has explained it

[Former Member]

[This posting has been removed]