Trying a different approach to a STOL

[Scotto]

I think something Ive learned from trying to fly very slow is what looks like a tip stall is more often a loss of yaw stability. I think my planes tails are "stalling" before the wings. So I am trying to correct roll at low speed with throttle and rudder instead of bashing the aileron stick.
I would like to see more pictures of your wing and its slats/slots.

 

[L Edge]

I think something Ive learned from trying to fly very slow is what looks like a tip stall is more often a loss of yaw stability. I think my planes tails are "stalling" before the wings. So I am trying to correct roll at low speed with throttle and rudder instead of bashing the aileron stick.
I would like to see more pictures of your wing and its slats/slots.

Will do. Let me finish up on my A-10 and I will.

 

[Piotrsko]

Perhaps your mains are behind the CG. Difficult to know from the story but slightly forward gear tends to prevent nose over. Tailwheel too high? If youre sure the wing is true then suspect torque for the right turn tip drag.

 

[L Edge]

Perhaps your mains are behind the CG. Difficult to know from the story but slightly forward gear tends to prevent nose over. Tailwheel too high? If youre sure the wing is true then suspect torque for the right turn tip drag.

Thanks for your wisdom. I agree with you on all points. It is nice to know what I have to look out for on takeoff. Had a bipe that the LG was too far aft. Same problem.

I'm stuck with what I got so I had left turn tip drag stuff as well. So you re-enforced what I am going to do.

For takeoff and hopefully a 1-2 ft altitude short run and successful landing, I will have 5 cups of coffee and will concentrate on rudder/elevator/throttle management. I am going to look for 20-30 winds(glad I put brakes on) and when I tickle the flight envelope. When it feels stable (hopefully hovering), will let it rip.

Like to hear from you.

 

[L Edge]

I think something Ive learned from trying to fly very slow is what looks like a tip stall is more often a loss of yaw stability. I think my planes tails are "stalling" before the wings. So I am trying to correct roll at low speed with throttle and rudder instead of bashing the aileron stick.
I would like to see more pictures of your wing and its slats/slots.

The wing on this project or some of my other stuff?
In fact, I have one you can chug along doing high alpha, hover in the wind, and handle gusty winds with ease. (have video)

Try this exercise.
Take the plane up 4 crash heights.
Throttle back and level, add elevator and aileron(no rudder) into a high alpha mode. Keep flaring slowly, plane will roll over and dive one way or other.
Go back up to same altitude after recovery and do it again. Plane in most cases will roll over same way.
Now climb up again, do the same except now as you slow down in high alpha, add opposite rudder to counteract roll, and slow it down(add more rudder) until it it rolls over and drops out.
Now game on, do it until it now is comfortable and keep it a tic away from stalling.

Heresa video;
If I use ailerons enough, plane rolls over to move right. Imagine adding too much aileron while doing a flare or high alpha near stall.
I use rudder, elevator, throttle management and a small amount of aileron to move from one side to the other. If I used a lot of aileron, wouldn't the plane roll over? So it becomes the rudder that allows it to move side to side.
My imaginary cube is 20x20x20ft to fly in. Run the speed of the video at .25 and watch the rudder, elevator, throttle change and see how little the aileron is used. After awhile, you will sense(feel) when you are near rollover.

 

[L Edge]

Back to this project-- Got to the point where I can level tail and keep going, but lifts off and tips forward or rolls left.. Moved CG forward, same result at 25% cord. Then changed prop from a 9 x 3/8 to a 9-7 and same thing happened. Played with flap positions.

Realized ground speed has not changed. My next try will be to get a larger motor and see if the extra thrust overcomes the high alpha drag of the wing when the tail is level. At least I still have a vehicle to continue to explore.

 

[RossFPV]

Back to this project-- Got to the point where I can level tail and keep going, but lifts off and tips forward or rolls left.. Moved CG forward, same result at 25% cord. Then changed prop from a 9 x 3/8 to a 9-7 and same thing happened. Played with flap positions.

Realized ground speed has not changed. My next try will be to get a larger motor and see if the extra thrust overcomes the high alpha drag of the wing when the tail is level. At least I still have a vehicle to continue to explore.

Could be thrust angle, try giving it some right thrust angle. You may have noticed that some ft planes have some angle built into the power pod

 

[sunrise30]

The wing on this project or some of my other stuff?
In fact, I have one you can chug along doing high alpha, hover in the wind, and handle gusty winds with ease. (have video)

Try this exercise.
Take the plane up 4 crash heights.
Throttle back and level, add elevator and aileron(no rudder) into a high alpha mode. Keep flaring slowly, plane will roll over and dive one way or other.
Go back up to same altitude after recovery and do it again. Plane in most cases will roll over same way.
Now climb up again, do the same except now as you slow down in high alpha, add opposite rudder to counteract roll, and slow it down(add more rudder) until it it rolls over and drops out.
Now game on, do it until it now is comfortable and keep it a tic away from stalling.

Heresa video;
If I use ailerons enough, plane rolls over to move right. Imagine adding too much aileron while doing a flare or high alpha near stall.
I use rudder, elevator, throttle management and a small amount of aileron to move from one side to the other. If I used a lot of aileron, wouldn't the plane roll over? So it becomes the rudder that allows it to move side to side.
My imaginary cube is 20x20x20ft to fly in. Run the speed of the video at .25 and watch the rudder, elevator, throttle change and see how little the aileron is used. After awhile, you will sense(feel) when you are near rollover.

Flying like a gee bee

 

[sunrise30]

I think something Ive learned from trying to fly very slow is what looks like a tip stall is more often a loss of yaw stability. I think my planes tails are "stalling" before the wings. So I am trying to correct roll at low speed with throttle and rudder instead of bashing the aileron stick.
I would like to see more pictures of your wing and its slats/slots.

I agree, why you will see bigger tail feathers on so STOL planes some times, slower speed more rudder authority, helping with yaw stability at slow speeds. My hypothesis

 

[FishbonesAir]

I agree, why you will see bigger tail feathers on so STOL planes some times, slower speed more rudder authority, helping with yaw stability at slow speeds. My hypothesis

I have a little airplane based on the Peck Prairie Bird. I dubbed it "Woodstock", because it gets pretty goofy in the air 🤪 sometimes, just like Snoopy's little yellow friend.

I'm planning a rebuild with bigger tail feathers, since low speed + wind - almost ANY wind are where it struggles.

It's 3 channel BTW.

 

[sunrise30]

I have a little airplane based on the Peck Prairie Bird. I dubbed it "Woodstock", because it gets pretty goofy in the air 🤪 sometimes, just like Snoopy's little yellow friend.

I'm planning a rebuild with bigger tail feathers, since low speed + wind - almost ANY wind are where it struggles.

It's 3 channel BTW.

Happen to have a picture of it? Like to hear how it goes.

 

[sunrise30]

Happen to have a picture of it?

 

[sunrise30]

High alpha and STOL devices are a kick to fly. Some work, others not so. I chose a real tough one . The DR Chinook.

Looking at some of the devices that he offers:
1) a raised leading edge of the wing
2) leading edge slot
3) endcaps
4) elevator that is angled
5)flap caps
6) oversize elevator control that produces a ground wake
and so on.



What I am going to do is build super light with a wing without any bracing and adding other devices that I have explored.

Since no plans are available, going to use some research and experimenting that I have done. Being "old school", out comes the paper, slide rule and drafting tools. This is what I have come up with using the gut feeling, study the figure over and over and going crazy. Finally I put the paper work away and now for the build.

View attachment 230797

So that is the starter. Leaving the wheel setup off for now to see if it will fly by chucking it.

I want to build a scale model of that Chinook

 

[L Edge]

I want to build a scale model of that Chinook

As I mentioned, there are no plans and I did my design work just from the video. Result, after building, was that I need a more powerful motor/prop setup which I never purchased. So if has not flown, will it?, don't know. Sorry.

 

[sunrise30]

As I mentioned, there are no plans and I did my design work just from the video. Result, after building, was that I need a more powerful motor/prop setup which I never purchased. So if has not flown, will it?, don't know. Sorry.

I have a parts sheet, and a full frame, from the full size one to work off of.

 

[sunrise30]

I have a parts sheet, and a full frame, from the full size one to work off of.

May try launching it with a big bungee, like a glider, short of a repower.
Did you try a few different props, three blade pusher, or a slow fly prop?

 

[L Edge]

I have a parts sheet, and a full frame, from the full size one to work off of.

If you have a full frame from the actual one to work off of, that reduces a lot of errors. With the elevator, wing, and flaps all at different angles, and only a video to watch and measure(error is great). Plane still is in testing condition, will give it a go in the future, When, sometime this winter.


Why don't you post what you are doing ?

 

[sunrise30]

Yeah, especially because almost nothing on that frame he is flying in the video is stock, very purpose built for competition. I am just at the design and materials phase, not much to post.

 

[sunrise30]

If you have a full frame from the actual one to work off of, that reduces a lot of errors. With the elevator, wing, and flaps all at different angles, and only a video to watch and measure(error is great). Plane still is in testing condition, will give it a go in the future, When, sometime this winter.


Why don't you post what you are doing ?

I may just try building the Storch for starters.

 

[sunrise30]

I may just try building the Storch for starters. That Chinook build is kind of in-between the ft explorer, simple stick and Storch. Design building has its trials and errors