Stopping the damn thing

[Paul Williams]

My experience flying models is still very much developing, I was wondering if I could beg some advice on slowing things down for landing. The one nitro plane I have is battered and bruised from heavy landings every time its patched up it gets heavier and I cant get the hang of using rudder to slow down. Whats the best way to scrub off airspeed quickly?

[David Ashby - Moderator]

What plane is this Paul? The answer may vary according to the airframe but generally speaking the trick is not to turn too quickly ie. leaving yourself too much height to loose which may means you'll push the nose down and speed will increase. 

Fly a good long down-wind leg and turn for finals giving yourself plenty of time and space to adjust the descent rate before the model touches down. Better to turn late than too soon as you can still use throttle to bring the model in. 

[Evan Pimm]

To slow down one must use UP elevator with LOW throttle (thrust). the only 'speed' control you have is drag, putting the nose down lowers the drag, which is why the model goes faster when you do so. UP elevator increases drag, and the model will slow down. Learn how to fly this thing at the minimum airspeed, practise flying it around rhe circuit as slow as the model will safely fly, use throttle to control height, and varying degrees of UP elevator to maintain this slow speed. Practise the circuit and landing/go-around a lot, and it will get much easier, and save  your model from further embarrasment .

Evan. 

[Former Member]

[This posting has been removed]

[Paul Williams]

cheers guys will try it out asap

[Evan Pimm]

One last thing, the slower you fly, the more you must use rudder to maintain direction. The use of aileron at a smidgeon above stall speed/angle will result in further model/pilot embarrasment.

Evan. 

[Andy Harris]

High Alpha Knife Edge down to 5m   (also useful in small fields and no wind)

This way you avoid the stall, you can keep visual separation till the last moment.

If the model is losing height all the way its easier to KE, if you're worried about inverting on a model with dihedral then use a 45deg version of a knife edge.

If you have a high wing trainer style model then elevator and angle of attack wll create drag.  I think this is more difficult that the KE or side slip mainly due to judging the stall point.

You could try out the two strategies on a sim to see which suits your style.

Andy 

PS has your CG changed with the patching ? 

[Paul Williams]

Andy, you come from different planet yes? High Alpha Knife Edge down to 5m, If the model is losing height all the way its easier to KE.

saying that to me is like me asking the Mrs to service the Volvo!!

Thanks very much for advice mate but english please, I always check CG before flying and probaly thats a lot of the problem to many patch ups on front has left half a ton of lead on the back, very heavy now great in winds though.

Your up early are you a milk man?

[Myron Beaumont]

Paul   He probably delivers fresh sticky buns to Timbo

[Andy Harris]

Sorry Paul

I pass it on as it was passed to me, perhaps it is club rather than universal language, the terms are in the BMFA handbook.

KE, or knife edge is where the wings are vertical, like you have at 1/4 and 3/4 way through a roll.

High Alpha means you have the nose pointing more skywards, say 30-35deg. 

The main wings have a large area and therefore the braking force is high, the fuselage has a lower area and therefore lower and more controlable braking force.

Generally up early in the hope of calm weather and empty fields....

Andy

[Paul Williams]

Cheers Andy, if the weather is the same as Manchester go back to bed with a good mag !!!!!!

[Former Member]

[This posting has been removed]

[Andy Harris]

Eric

  Alpha is the "angle of attack" --  in the K.E. this would be the fuselage.

Google returns a grillion entries:

http://www.google.co.uk/search?hl=en&client=firefox-a&rls=org.mozilla:en-GBfficial&hs=2nV&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=%22high+alpha+knife+edge%22&spell=1

The first video is an example of a level flying H.A.K.E:

http://uk.youtube.com/watch?v=Lag9qtkkCkY

This is not quite what I meant because the goal was to lose height without trading it for speed. 

I'm not  an authority, more a learner by mimic, I've also heard the phrase 'side-slip'  used by older gentlemen, although I believe this refers to the same practice in a more gentle fashion with the wings at 45 deg.

 This weather is denying flying so much I've started Googling for indoor 3D models.

Regards  ... Andy

PS Next time I'm out I'll be after a falling horizontal loop, 3 times and out level into wind .... guess it'll take an hour or so to learn. 

[Evan Pimm]

I must be getting old...sideslip is/was nearly always done with wings more or less level, a bootful of rudder and cross aileron to maintain wings level. (My ppl training, you understand) Yes, it can be done standing on the side of the strip, but for a beginner it's a bit like trying to land in knife edge flight, a bit difficult and fraught with possibilities. We should stick with the simple stuff, then introduce  these other bits once competence is assured.

Evan. 

[Paul Williams]

Your doing me head in !! I asked where the brakes are

[Andy Harris]

Paul

 ... The brakes are the control surfaces, the more they move from centre the more they brake.

 ... The trick is to pick two and get them moving against each other ...

    You've not yet told us what you're trying to slow down, all we know is that its a nitro ...

 Reading some of the other threads about the maths can do my head in 

 Regards .... Andy

[Evan Pimm]

In most of the aircraft i've flown the brakes were under me feet on the rudder pedals...they didn't work when the things were flying either, something to do with the lack of contiguity twixt wheel and ground...All of the above wheezes will work, you just have to go out and practise, two mistakes high.

Evan. 

[Paul Williams]

Ha Ha I did think I have left myself wide open there, Its a heinz 57  just made up on the bench but basicly its overwing 50" span square fug, Tell you what I'll put a pic on after work got to go keep Britain from grinding to a halt.

[Alan B]

Hi Paul

You could always try using a larger prop and a lower pitch to slow things down generally.

[Tim Mackey]

Exactly.

[Paul Williams]

Oh no I like flying fast gets the old adrenalin going, I just have a problem stopping before I run out of field.

[260 Flyer]

Paul

Have you calculated the CG position or just gone for the usual 25-30% mark? It sounds like you might be a bit nose heavy.

Or you may need some down thrust. If you trim for level flight at half throttle will it go into a dive when you shut the throttle?

Rob

[Paul Williams]

I would not know how to do the calcs for CG, just guessed it mate. I will try your test method as soon as weather permits. The engine is set at the usual down and right.

thanks

[Former Member]

[This posting has been removed]

[Paul Williams]

Ah the wit I knew I went on here for something, Eric you are right and since posting this its not stopped raining or that awful thing work has got in the way of play time. Its all about practice I am sure. I like the idea of nose up an find stall point rarther than the more elaberate methods mentioned eariler. Thanks for your time fella.