Air Brakes... On a Wing?

[hreehoorn]

I don't have a lot of good experience with wings and I just built a Goblin at 130% and I was skeptical of the build to begin with, just cuz it ended up being so heavy compared to anything I have built before just to balance it. I flew it and did a stall test and I will show you what happened here, I was so surprized, check it out at 6:28 and about 7:20

Now I actually added a third set of rates since this maiden where what used to be the high rates is now mid rates, and the now high rates are the same as the mids but I have maxed out the elevator at 125% just for short soft landing. If you don't have the space or an endless supply of props this would save you. I took it out today and the high rates trick worked amazing, no broken prop. And if you land in a head wind it will hover all the way to your feet. It reall isn't that hard to do, both sticks full back all the way to the ground, a little flare at the end. Good Luck

Thanks for sharing man! I flew a few goblins at Flight Fest Texas last year and while they aren't technically a wing, they are damn close and I felt behave a lot like one. So your input is 100% valued to me!

 

[Merv]

I agree with @Ketchup, I recall a FT video, a long long time ago. They found that tradition rudders were ineffective on a wing. They used a single rudder, not a split, on each wing tip. Each rudder deployed only one way, outwards. When you wanted to turn right, deploy only the right rudder, causing drag and yawning the wing to the right.

This single rudder on each ting tip would be far easier to build and program than any split system.

 

[quorneng]

A delta, so not strictly a 'wing', but it has no real stall as such and allows a true 'flop' landing.

 

[L Edge]

I explored the use of air brakes many moons ago(program drove me nuts) and as others have said, it ends up giving you a steep approach.

Problems occured due to not having identical movements(individually) and as a pair causing yaw and pitch problems. Initially, was going to use it on my Shuttle and X-47B. Only way to get it to work is by using a flight controller.

Using the "KISS" method, why not do this to slow your hot approaches.

1) Set up a two position switch. One mode will be for regular flight.
2) Mode two will be for landings.

Concept:
Mode two will require 1 click of elevator trim up. Now go up 3 crash heights. Slow your wing down and practice approaches. You are looking for a slight nose up attitude (just like being in a airplane) where low throttle keeps it flying, but it will actually slow down for you due to additional drag on a approach pattern.
Still doesn't work, land, add 1 click of additional of up trim, go up and try again. Repeat until you have a positive flair to slow it down, but far enough away to being close to stall and rolling over. With practice, you then will be able to use throttle and elevator without the trim.


Good luck!!

.

 

[Merv]

I explored the use of air brakes many moons ago(program drove me nuts)

Well done, how many mixes did that require?

 

[L Edge]

Well done, how many mixes did that require?

I think it was 5 different mixes to get to work right. That's why when you buy a radio, look at the capabilities of the mixes.

 

[Merv]

Here is the FT video from the way back time machine, circa 2011, enjoy

 

[Vimana89]

A delta, so not strictly a 'wing', but it has no real stall as such and allows a true 'flop' landing.

Perfect example, although much more natural on something like your HP-115 than a basic flying wing. As someone who builds lot of deltas and low aspect planes myself, I use this landing method often(though it rarely looks quite as graceful as your own clip). With a stall proof plane like a slender delta, it's fairly easy to control the whole process, but I'm thinking some other types of planes may even need to initiate a stall in order to "flop"(?).

 

[Vimana89]

Here is the FT video from the way back time machine, circa 2011, enjoy

That looks pretty nice. Like they said the yaw needed some work, but the air brake thing was actually extremely effective

 

[Merv]

That looks pretty nice. Like they said the yaw needed some work, but the air brake thing was actually extremely effective

Yes, I believe if they had more throw and/or larger rudders, they would have had more yaw control.

 

[thenated0g]

didnt read thru all the comments so sorry if repeat. I have seen flying wings, in slope soaring i should say, with various means of slowing down. Pop up spoilers that are in the middle top of the wing, I have seen it where the rudder is actually 2 parts and opens up like a flower, left and right, and i have seen it where you have flying planks that have ailerons and elevators and you have the ailerons both go up and the elevators both go down, countering eachothers deflection to keep the plane flying straight but creating drag. If any of these interest you let me know and i can probably find links/pics.

 

[Michael9865]

I have not tested the tip brakes yet on my Divinity wing.

Here is the original Divinity post that I was going to try. https://www.rcgroups.com/forums/showpost.php?p=27674132&postcount=777

I have also been debating on building another wing with two center plates so that I could experiment with splitting the outer two thirds of the ailerons in this manner like Merv showed. I remember reading in a thread that to roll left you can have the left top half go up and the lower right half go down while the left lower and right upper halves stay in their respective neutral positions. The yaw control would be controlled through the splitting of the ailerons to create drag.

 

[thenated0g]

 

[L Edge]

Here is the original Divinity post that I was going to try. https://www.rcgroups.com/forums/showpost.php?p=27674132&postcount=777
View attachment 151466 View attachment 151467 View attachment 151468 View attachment 151469
I have also been debating on building another wing with two center plates so that I could experiment with splitting the outer two thirds of the ailerons in this manner like Merv showed. I remember reading in a thread that to roll left you can have the left top half go up and the lower right half go down while the left lower and right upper halves stay in their respective neutral positions. The yaw control would be controlled through the splitting of the ailerons to create drag.
View attachment 151470

I looked at that when I designed my X47B and what it would realy take to control it was no possible.

Here is the original Divinity post that I was going to try. https://www.rcgroups.com/forums/showpost.php?p=27674132&postcount=777
View attachment 151466 View attachment 151467 View attachment 151468 View attachment 151469
I have also been debating on building another wing with two center plates so that I could experiment with splitting the outer two thirds of the ailerons in this manner like Merv showed. I remember reading in a thread that to roll left you can have the left top half go up and the lower right half go down while the left lower and right upper halves stay in their respective neutral positions. The yaw control would be controlled through the splitting of the ailerons to create drag.
View attachment 151470

Now that they have 3D printers, it would give some good results as to what happens.

 

[varg]

Yes, with access to CAD and a 3D printer, it would be fairly easy to make those split ailerons.

With most flying wings, you can just bring it to the edge of a stall (if it even will stall, some you can just pull back and float in) and mush it in. If it's truly a fast mover that doesn't slow down well due to high wing loading or wing design there's really nothing you can do, it will only fly so slow before a stall. FT planes tend to be draggy and don't need any help losing speed, just throttle back, no need to plan the approach out like with a slippery glider or racer.

These days, reversible ESCs are something one might consider for an air brake. ESC brake on, let the prop stop, then give some reverse throttle. Won't take much to slow you down fast. It's all already there, no added weight or complexity, just a TX mix and a capable ESC needed.

I find "just using a pencil" preferable to developing a "million dollar pen that writes in space" if possible as far as solutions go.

Turns out graphite particles floating around in a spacecraft aren't a very good idea.