HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 12, 2012, 11:02 PM
Registered User
United States, CA, Livermore
Joined Jan 2012
916 Posts
Discussion
spoileron elevator mix

I am considering using spoilerons (both ailerons up) to help reduce the "floatiness" of my high wing trainer (Alpha Sport 450) during landings. Reading through the threads, it seems that I should mix some elevator in which is easy to do on my DX6i. However, I am confused as to which direction of elevator trim to use. I have seen threads suggesting both up and down.

So here is the simple question. On this sort of plane, which direction will the nose tend to go when I deploy the spoilerons?
rhodesengr is offline Find More Posts by rhodesengr
Last edited by rhodesengr; Nov 12, 2012 at 11:14 PM. Reason: typo
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 12, 2012, 11:15 PM
Yea, I fly dusty planes..
zeezee's Avatar
United States, LA, Angie
Joined Apr 2009
2,052 Posts
You are correct on maybe using some elevator, but before you do get some good altitude before you do any testing and also do not deploy at a speed you wouldn't be using if you were not landing. I have deployed flaps at higher speeds which caused it to balloon up suddenly, not a good thing if your a not 3 mistakes high. Flaps generally need a little down elevator mixed in but if you get it right and practice you may not need it. I used spoilerons and never needed any elevator mix as I was throttling down on a slow landing approach. Just take it slow and easy and practice up high but so that you can see it well. I had that ballooning issue with my P-51 and Pawnee until I slowed em down a bit. I dropped the flaps on the big P-51 just about 80 degree's down and used them as airbrakes, thus no lift. I do like spoilerons. Good luck, Dave/ZZ your last ?...UP!!!
zeezee is offline Find More Posts by zeezee
Reply With Quote
Old Nov 12, 2012, 11:23 PM
Registered User
scirocco's Avatar
Australia, ACT, Kambah
Joined Feb 2001
3,098 Posts
Quote:
Originally Posted by rhodesengr View Post
I am considering using spoilerons (both ailerons up) to help reduce the "floatiness" of my high wing trainer (Alpha Sport 450) during landings. Reading through the threads, it seems that I should mix some elevator in which is easy to do on my DX6i. However, I am confused as to which direction of elevator trim to use. I have seen threads suggesting both up and down.

So here is the simple question. On this sort of plane, which direction will the nose tend to go when I deploy the spoilerons?
For small spoileron deflection, you shouldn't get a lot of pitch change, but, to compensate for the loss of lift at the speed you're flying when deployed, you'll need some up elevator. Also on a high wing trainer, I started off with small increments of spoileron and some compensating up elevator and worked up to a useful amount - which I can't recall exactly right now - but it wasn't much, maybe 20% spoiler and 5% up elevator. Now when I pop the switch, it just steepens the glide path nicely with negligible change in attitude - fewer floating flybys and go arounds is nice.

Went and checked flap settings on my trainer - 30% flap up and 26 units nose up elevator
scirocco is online now Find More Posts by scirocco
Last edited by scirocco; Nov 13, 2012 at 01:14 AM. Reason: checked tx setup
Reply With Quote
Old Nov 13, 2012, 02:34 AM
Joined Nov 2011
936 Posts
...
Logan4169 is offline Find More Posts by Logan4169
Last edited by Logan4169; Mar 06, 2013 at 10:44 PM.
Reply With Quote
Old Nov 13, 2012, 10:47 AM
Taranis Tyro...
MattyB's Avatar
United Kingdom, England, Hitchin
Joined Jan 2004
3,708 Posts
The problem with spoilerons is that the compensation direction can be different depending on the tail moment and wing section. I fly mostly slope gliders, and most of those that have spoileron control require down elevator comp. However the shorter coupled versions tend to require up - no, I don't know why either! The best recommendation is to start with small amoints of spoileron an no compensation, and try it out at height - once you know which way the compensation will be it's much easier to get everything trimmed out without a hairy moment!
MattyB is online now Find More Posts by MattyB
RCG Plus Member
Latest blog entry: My OpenTX Taranis templates...
Reply With Quote
Old Nov 13, 2012, 11:38 AM
Registered User
United States, CA, Livermore
Joined Jan 2012
916 Posts
Quote:
Originally Posted by MattyB View Post
The best recommendation is to start with small amoints of spoileron an no compensation, and try it out at height - once you know which way the compensation will be it's much easier to get everything trimmed out without a hairy moment!
This is now my plan. If I wasn't stuck at work, I'd be out trying this now.
rhodesengr is offline Find More Posts by rhodesengr
Reply With Quote
Old Nov 13, 2012, 02:24 PM
Registered User
Joined Mar 2010
1,337 Posts
Good luck
rtbates is offline Find More Posts by rtbates
Last edited by rtbates; Nov 13, 2012 at 04:46 PM.
Reply With Quote
Old Nov 13, 2012, 02:56 PM
Registered User
scirocco's Avatar
Australia, ACT, Kambah
Joined Feb 2001
3,098 Posts
Quote:
Originally Posted by rtbates View Post
You'll learn a whole lot more about flying if you don't. Large/heavy planes, a times, need these aides. A light weight trainer shouldn't.

Each to his own, said the man as he kissed the cow.

Good luck
I would suggest that large/heavy aircraft with their higher wingloadings and higher power off sink rates are less likely to benefit from spoilerons than a floaty trainer. I wouldn't typify gliders as large/heavy planes, but use of spoilerons for glideslope control is commonplace.

On a lightly loaded trainer, the power off glide can be shallow enough that a range of factors such as obstacles in the approach area or a short runway can make landing more challenging. So why not use a readily available - trivial in fact exploiting dual aileron servos and even low range computer radios - capability that improves the overall experience? Better to use spoilerons and touch down at low speed in the first third of the runway than to stuff the nose down, jam it on the ground at high speed and wonder why it bounces and/or the gear keeps tearing out.

Why discourage a landing aid for a trainer when most full size aircraft rely on lift and drag devices to manage glideslope, especially when our fly by wire systems allow easy use of spoilerons with zero added weight and complexity, unlike adding flaps for example?
scirocco is online now Find More Posts by scirocco
Reply With Quote
Old Nov 13, 2012, 04:36 PM
Registered User
United States, CA, Livermore
Joined Jan 2012
916 Posts
Quote:
Originally Posted by scirocco View Post
Why discourage a landing aid for a trainer when most full size aircraft rely on lift and drag devices to manage glideslope, especially when our fly by wire systems allow easy use of spoilerons with zero added weight and complexity, unlike adding flaps for example?
Well I am with you. The bottom line is I am new to flying planes. I can fly it around just fine but I don't want to break it landing. So far my buddy box pilots have broken landing gear off completely once, bent one of the three wheels several times, and ground a few mm's off my prop on the runway. The wing tips have hit the runway three or four times but no real damage there. These are guys with around 20 years of experience. So you can see why I am concerned about improving the landing characteristics before i try it myself. I am sure that any of those guys with some practice to get the feel it of could land it better. I would like to not destroy on my first solo if at all possible. The spoileron method does sound promising. I am just frustrated that bewteen the wind and work its hard to find time to try it.
rhodesengr is offline Find More Posts by rhodesengr
Reply With Quote
Old Nov 13, 2012, 04:44 PM
Registered User
Joined Mar 2010
1,337 Posts
good luck
rtbates is offline Find More Posts by rtbates
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Flap and elevator mix Davey NY Electric Plane Talk 21 Jun 09, 2014 09:09 AM
Discussion Mixing Aileron And Elevator (V-Type Mix) -How To Waleed Radios 20 Oct 15, 2012 07:45 AM
Discussion Dual elevator setup with DX8 - use mix or program servos? Daedalus66 Radios 14 Mar 25, 2012 01:37 PM
Discussion elevator to flap mix using aileron servos?? big bird Hitec/Multiplex USA 2 Mar 21, 2012 05:15 AM
Discussion Spolieron - Elevator mix tofuti Sailplane Talk 7 Aug 25, 2009 05:49 AM