Ok so I picked up old Joe 105in ME 163 It has 2 controls per wing, and the owner said the inboard ali were used as flaps during landing.


This seems conflicting, can a tail less plane use flaps? or Would it actuly be more of a crow, as the inside ali/elv would be going down and the out board ali would be going up as in typical delta wing flight?


As all my delta wings need relex, or up ali/elv to fly level.

I have a delta with flaps but I dont use them, on a delta they just act like down elevator more than helping anything.

Just my .02

Good question. I went back and reviewed some old movie footage of 163's flying during WWII and at first glance it appears that they had extended flaps for landing. But on more careful viewing, the flaps are not on the trailing edge of the wing. They are flat panels on the lower surface only, and are about 60% of the way back from the leading edge. So they are in fact spoilers, not flaps. They would be used to steepen the glide path to assure an accurate landing spot, just like any modern glider.

The spoilers on the 163 are no doubt positioned such that they create little or no pitching moment, while at the same time creating needed drag. Note also that the 163 isn't really a delta wing. It's a swept wing tailless aircraft. So the actual position of the spoilers is quite near the CG compared to the elevons.

Link to movie below. You can see the extended spoilers on landing at about 2:50 and at 4:12 into the movie. And then a pretty clear shot of the lower surface of the wing at 4:42.

Dick

https://www.youtube.com/watch?v=kMScNZFg0k4

As Dick says, there are flaps on the wing bottom, and what looks like a flap on the inner wing's trailing edge is called trim tab (Trimmklappe) in the German Wikipedia article (good pictures showing the flaps there). The English article isn't bad either. The airplane had also fixed leading edge slats on the outer wing parts. (Not a bad idea for the swept wing.) You may also see 3views of the A and B versions.

Here is flaps (crow) used on a plank wing to land in challenging places:

https://youtu.be/R7cDeu1Kd3s?t=2m20s

It's tricky to get it right, the pitch is constantly changing according to airspeed. This is a lucky shot.

The 163's inner trailing edge 'elevators' were for trimming the pitch change caused by the under wing flaps. Deltas really don't need them (flaps), providing the balance is right and you can get the wing up to the large alphas deltas can use...the drag increase is huge and the speed can be really slow, flaps really wouldn't work with them...generally it means that if you are using a prop it needs to be at the front...
Evan.

Ok, SO Should I just link them to the match the outside control surface for elevator movement only? That way the out side panels are programed as elevons, and the inside ones would just have a mix that would follow the elevator movement.

Im going to fiberglass the wing next week, so im making corrections now. I was thinking of adding the lower flaps but it looks like the servos are in the way. I also thought about adding the front leading edge slats, but I had a buddy at the museum that sent me some pics of the real one and the leading edge looks like it would be real weak as this is a foam wing.

mikes68charger
It would perhaps be more logical to use the outers as ailerons and the inners just as elevators.
As a flying wing rather than a delta the control surfaces are close to the CofG and particularly at speed small movements have a significant effect so it is unlikely you will all four surfaces as elevators. .
As elevons it might take some effort to eliminate any unwanted pitch change with aileron movement and vice versa. Keeping pitch and roll control on different surfaces should keep it simple to set up.

Northrup's prototype flying wing used flaps. Check it out on Youtube.

This is the way to set it up:

He is dead on about you not wanting the inner and out control surface as elevator, it make for a very pitch sensitive setup that needs a ton of expo on the elevator to work.

Thanks. I should of posted. I got 11 flight or so.

I use just the out bord controls as elevons, and make the inside ones come down about 15deg as flaps which cause more drag, it’s like crow. Helps to kill the ton of lift and slickness of the fuse.

I cant believe with all the added weight of my turbine conversion I have to shut the motor off to land or it glides forever!

Thinking of making a takeoff mode where the inside controls will follow the out side elevator just to takeoff.

This is this is so aerobatic it’s amazing to fly

Looks like you were having a lot of fun with it.
It is truly an amazing design considering it designed some eighty years ago.