Flaps

[Richie P]

I read with intrest jim newman's article on flaps in the may issue of rcm&e, every time i see a model landing with the use of flaps ( and that's not many i must say ) but  to me it' gives the model that extra bit of class, it's something you don't expact to see. but i am confused? jim if you pick up on this thread or anyone who can help please reply. i am just putting my new easyglider together only to read in the instruction manuel that both  ailerons can be deflected up simultaneously in order to provide a "spoiler" funcion to shorten the landing approch, and at the same time use a small amount of down-elevator. yes i know that a true plane has both ailerons and flaps but with the easyglider you use the ailerons to get the same effect, but why are they defelcted up and not down as normal flaps are, sorry but this has confused me, i am going to use the spektrum dx6i 2.4ghz that allowes for mixing for this to work

happy flying richie p

[Tim Mackey]

I fitted spoileron setup to a slope soarer of mine, and its main purpose in that application is to "dump lift" by altering the camber of the wing shape, which allows the model to quickly lose height and hopefully arrive at the spot intended instead of just overshooting. The altered camber of the wing causes it to tend to pitch up, so a little down elevator is automatically mixed in as the spoilers are deployed

[Former Member]

[This posting has been removed]

[Richie P]

thanks eric thats very clear and understandable,

timbo on what you done to your slope soare is it possible for me to modify the wings of my easy star to have alerions or will i create a problem 

[Tim Mackey]

Any model which utilises a seperate servo in each wing panel for each aileron can be setup as spoilerons

( assuming your radio has the mix setting...and most modern sets do )

Whether or not a particular model needs or would benefit from them...thats a different story ! As for fitting ailerons to the easy star...well I guess it could be done, but the shape of the wing does make it easy and even then I think it would need to be a single fus mounted servo and torque rod affair. Not worth it IMO.

[harry]

hi richie            the November 07 edition of Radio Control Model World featured upgrading the easy star with ailerons plus larger rudder and single undercarriage. You should be able to get the back issue from the said magazines back issue service.Sorry to mention another magazine on this forum but we are big boys arent we ? hope this helps.        Harry

[Tim Mackey]

Naughty step for you Harry - RCMW indeed

[Richie P]

ar well harry looks like i'll have to wait for the RCM&E to do the alteration if they want in the summer

[Simon Chaddock]

Flaps, spoilers & ailerons - it all depends on what you are trying to do. For example a high performance sail plane may use small amounts of down flap to improve the low speed performance or up flap for high speed flight. Its very high aerodynamic efficiency means spoilers (&/or high down flap angles) are required to simply increase the drag to allow a reasonably steep approach to the landing area. The actual landing speed is not usually a problem. Normally the ailerons are left alone to ensure adequate lateral control.

Fast powered aircraft eg airliners may use absolutely everything. To achieve the required speed and range the wings are relatively small compared to the aircraft weight, hence complex area increasing flaps & leading edge slots are required to maintain lift down to a reasonable landing speed. Fast acting spoilers and lift dumpers are used to adjust speed and rate of descent. They may also be used differentially to assist the ailerons.

So it will depend on your model what sort of flaps you might need (unless you simply are after a scale effect). As Eric stated above LOWERING the ailerons as spoilers or flaps is not to be recommended as you will most likely get a tip stall as you slow down and loose control. Yes there are aircraft that droop their ailerons but always in conjunction with, and less than, the main wing flaps so that some lateral control remains even when the rest of the wing has stalled. 

[Mark Lubbock]

Not a good idea to use ether inset(outboard) or full span ailerons as flaps (downward moving) as this would make the model very prone to tip stalling . Inset  ailerons can be raised as mentioned earlier, but the ultimate is raised ailerons, combined with dropped inboard flaps known as 'crow' braking-look at a bird landing & you will see where this name came from. Using this method, a very steep approach can be flown without gaining speed & minimal risk of tip stall-elevator used to control speed as usual.

Hope this helps.

[Richie P]

thanks for the replys, it makes interesting reading and educating for myself