From: barnabywalker <barnabywalker@yahoo.com>
To: Sport_Aircraft@yahoogroups.com
Sent: Tue, December 21, 2010 2:29:20 AM
Subject: Light-Sport Aircraft Yahoo group Re: Spoilers versus ailerons
--- In Sport_Aircraft@yahoogroups.com, Roger Poyner <rogpoyn@...> wrote:
>
> Full span was out from the get go. Just a waste of tubing and weight.Â
> Spoilerons are simple and light. That was the main reason Dick went with them.Â
> I try any ideas off of him as they come up. Adverse yaw can be reduced a lot
> with differential ailerons which is what I will use. Dicks guidance reccomends
> using 6" spoileron plates instead of the original 4". I am going to use the
> wider plates. I also have a stock TX so I can see the effects of both sizes on
> the planes. I am not the owner of Starflight aircraft but am the owner of the
> Starflight yahoo group. I get asked questions quite a bit. I just need to
> learn more to give better answers. Roger P
Of course, you should use differential ailerons!
But you're totally missing the boat if you ignore the 1/3 length ailerons. Too many in the Ultralight industry got bigger bragging rights by building ailerons which were too long and would still call their models which the wings are fitted with 2/3 of the length in ailerons "full-span". All of today's production quicksilvers greatly improve when a foot and a half is chopped off inboard of each aileron. That inboard section of each too-long aileron does you no good, instead much harm from the resulting adverse-yaw and much higher stick loads.
Much has changed from Ultralight experiences since the early 80s, just not with the production plants who still sell antique 1980 design.
Even a Chinese Cessna would have 2/3 length of the wing in flaps, 1/3 length ailerons ratio as do most of the Cessna models. Replacing aileron control cables with pushrods is also an improvement we didn't use in the 80s, but now provide much snappier handling. MX spoilerons have 2 wide plates attached together length-wise on each wing BTW, and they still don't provide much value. Spoilers used in early days because they were cheap and easy and created 2 1/2 Axis flying machines. But, we've graduated from them to ailerons since the mid-eighties to create full 3-Axis. This is also the time when every ultralight grew heavier than 254. But factories continue to sell them and people safely fly them with much better control than in the beginning of ultralights. And never forget you are really flying primarily a Rudder plane even when equipped with Ailerons, so best to teach students how to fly primarily with Rudder. Then they are totally prepared when stepping into one equipped only with Spoilerons.
A good design I talked to Dick Turner about at Sun n Fun was a twin engine which had the engines offset fore and aft a bit to allow the inboard prop radiuses to be overlapping and avoid offset thrust problems. He was intending to sell them in Argentina. Since that time, I found that setting the engines side-by-side so the prop tips were only a couple of inches apart was sufficient, as most twins have the separation between thrusting engines of at least a double-width cockpit.
Barnaby
> ________________________________
> From: barnabywalker <barnabywalker@...>
> To: Sport_Aircraft@yahoogroups.com
> Sent: Tue, December 21, 2010 1:03:10 AM
> Subject: Light-Sport Aircraft Yahoo group Re: Spoilers versus ailerons
>
>
> When building your ailerons, make sure to not make them longer than 1/3 of each
> wing. This greatly reduces adverse yaw as the center 2/3 which would normally
> contain flaps, should be avoided or the inboard sections of ailerons at a short
> moment arm would cause drag, hence the adverse yaw. Lightens stick load
> tremendously from those who copy tail-sliding tractor-propped aerobatic planes
> with "full-span" ailerons that sound good to marketing-types, but perform poorly
> with a pusher,because of the tremendous adverse-yaw and heavy stick loads.
>
> I wouldn't bother with spoilers as they provide so little bang for the buck,
> providing only lowering and not raising the opposite wing. Your Flightstar
> probably flies quite well now with Rudder only,as Dick Turner designed it much
> like the Quicksilver and has lowered the dihedral greatly from the original. 1/3
> length ailerons with sufficient throw should make it a quite nice handling
> plane.
>
> Like I said, I would stick to dual-control 1/3 length ailerons and no
> spoilers,simply teach all students to fly with their feet, as Rudder is such
> dominant control with these type of craft and once checked out in your plane
> will have no problem with a spoiler plane.
>
> Barnaby
>
> --- In Sport_Aircraft@yahoogroups.com, Roger Poyner <rogpoyn@> wrote:
> >
> > This post relates to airplanes and I hope it doesn't put me on moderated status
> >
> > for clouding up the site.  For years I have been hearing the merits of
> >ailerons
> >
> > over spoilers for roll control on light planes. I think I may try to settle or
> >
> > spur this debate on again. I am going through my Starflight DBL on an
> >extensive
> >
> > check out. One of those that takes a look at every nut and bolt on the plane.Â
> >
> > The plane was originally built with spoilers for roll control to avoid adverse
>
> > yaw that can be induced with ailerons. I started to build a set of ailerons to
> >
> > add to the plane because that is what I am used to flying GA planes. I started
> >
> > flying in Weedhoppers in the mid 80s with two axis control and have flown the
> > DBL in a two axis configuration and was impressed with how well it handled.
> >
> > Since I will replace the wing sails at any rate and add the dual controls for
> > the ailerons my idea is to install both ailerons and spoilers on the plane.Â
> >The
> >
> > plane is a tandem two place and the front seat will have two control systems
> > installed that are separate from each other in the front seat. While both will
> >
> > share elevator control they will be on there own for roll. Center stick for
> > aileron roll and right side stick for spoiler control. Production models of
> > Starflights still use spoilers so the plane should work fine as a trainer for
> > either system. Intial test flights will be solo of course and the redundant
> > flight controls can be tested one at a time. The spoilers with the side stick
>
> > and ailerons with the center control stick. Dual control sticks will only be
> >in
> >
> > the front cockpit with a center stick in the rear. For spoiler training the
> > center stick will be removed.Â
> >
> > I just want to get a feel for both control systems and understand the merits of
> >
> > each. Any one have any thoughts? Roger P
> >
__._,_.___
No comments:
Post a Comment