What flap/spoiler settings for my plane? (FAR)

[eempc]

I just discovered this tweakable, which apparently can help me with landing my planes. I previously landed at 150 m/s which was a bit too fast for my liking and I hear that flaps and spoilers can help in that respect. I just don't really have a clue what settings to use and where.

I have bound Increase Flap to 9 and Decrease Flap to 0. Does pressing 9 increase my lift so I can stay airborne at a lower speed without stalling?

Should the tailplanes have flaps and/or spoilers activated? What value should I set "Flaps/Brake M..." to?

Should the wings have their flaps/spoilers activated? Also what values are good?

[kujuman]

I have bound Increase Flap to 9 and Decrease Flap to 0. Does pressing 9 increase my lift so I can stay airborne at a lower speed without stalling?

What it does is increase the angle of attack (AoA) of the flap relative to the wing. Increasing AoA will generally pass through three stages, in increasing amounts of AoA: 1) increase lift, 2) increase lift and drag, 3) stall the wing, massive decrease in lift, increase in drag. Long answer short: yes, you can fly more slowly unless your flap/brake max setting is too high.

Should the tailplanes have flaps and/or spoilers activated? What value should I set "Flaps/Brake M..." to? Should the wings have their flaps/spoilers activated? Also what values are good?

I try to keep my flaps centered around my center of Lift. If your flaps are behind you center of lift and they then create more lift, your plane will tend to pitch down. So flaps on the tailplane can cause your plane to nosedive. Spoilers on the tail will tend to do the opposite and pitch the nose up.

"Flaps/Brake M..." is Flaps/Brake Max angle. Flaps get set in four settings. At flap 0, AoA is 0. At flap 3, AoA is Flaps/Brake Max angle. Flap 1 and flap 2 provide intermediate values. For simple aircraft, a good starting place for flaps is 40. If you use the FAR analysis tools you can tweak these values to get the performance you want.

For a starting point I only use flaps on the wings unless I'm doing something special. An example of this:

Sometimes my spaceplanes will have the Center of Mass shift very far forward when they are low on fuel. This can make keeping the nose up difficult. To solve this, I sometimes add positive value flaps to canards or negative value flaps to my tail plane.

I hope this helps

[Hodo]

I never set any flap settings to my tail section. And no longer use them on any true delta wing designs I have been making lately.

The ideal flap placement should be near your CoM. So if your CoL is where it should be, right behind your CoM you should have no problem placing your flaps on the trailing edge of the wings. I also have my flaps set to 9 and 0 and it works fine. I use one notch of flaps for take off on many of my craft, and 2 for landing and 3 once on the ground to increase drag. Kind of like a Boeing 747 on landing.

I use TAC Fuel Balancer for my fuel shifting issues. But I also use it for moving the CoM on some of my more unstable aircraft, that go hypersonic to get out of the atmosphere. One of my designs, the CoM can be shifted almost 2m from front to back with the fuel. This helps because when it is flying subsonic its CoM is a hair in front of the CoL. When supersonic the CoL moves way back making the nose extremely heavy, so I shift the fuel back towards the tail and it puts everything back inline.

It is amazing what you can learn by watching Youtube......

As for spoilers, I really don't use the ones in the FAR settings. I use the B9 air brakes most of the time, just easier to set the to brakes and not worry about the additional settings. But that is just pure laziness on my part.

I do highly suggest you set your control surfaces to match that of most real aircraft. There is a reason why they are setup the way they are. If unable to find a real aircraft to look at either on a video, or in a flight sim (a good one), find a window and watch a bird fly, hawks, eagles, vultures, seaguls and crows are some of the best to watch as they have large wings and often are just gliding on the wind and fine tuning their flight with their flight feathers.

Edited July 13, 2014 by Hodo

[Master Tao]

Positive flap settings do three things: increase lift, drag, and pitch down moment. With your main wing set so far back you will almost certainly need to counter balance the flaps with increased pitch up authority. An easy solution is negative flaps* on the tail, which simulates pulling up without changing your control authority. In the picture below, I have similar settings with canard foreplanes. The canards pitch up at the same time as the flaps pitch down, and I've tweaked them all so that the nose stays level at all flap settings.

BTW, Hodo, Ferram is reducing the air brake drag to 1/5 because they're currently a little over powered. Meaning they can easily cause more drag than the rest of the airplane combined.

*Technically, those aren't flaps any more. It's more like fly-by-wire compensating for the flap settings.

[Hodo]

BTW, Hodo, Ferram is reducing the air brake drag to 1/5 because they're currently a little over powered. Meaning they can easily cause more drag than the rest of the airplane combined.

Good to know, wont affect any of my designs as I don't go crazy with airbrakes anyway. And I already adjusted my air brake settings to 1/3rd lol. Got tired of them stopping an aircraft in flight.