Aircraft Design Problems?

[BamBam]

so, i am trying to build and fly airplanes from the runway. trouble is, i cant seem to get anything that flys halfway decent! i built a small fighter jet style plane, nothing more than 3 fuel tanks, an engine, tricycle gear, and the wings were 3 parts each (a leading edge, a leading edge turned backwards, and a delta wing snapped onto the back of that). plus a rudder and flaps on the wings.

with this plane as with all others, it either swerves around on the runway (with zero control input mind you), or it picks up speed around 150-175 m/s but wont lift off till it runs off the end of the runway. i have tried tiny little planes with way too much wing, huge planes with the huge bus lifting wing, bi-planes, none of them will pick up their nose wheel and properly lift off the runway.

what am i doing wrong?

and why do planes swerve about on the runway instead of moving in a straight line?

[sal_vager]

Hi BamBam

There\'s a glitch making the runway sticky, and sometimes a wheel will sink a bit, making aircraft turn.

I have also found that if wings are overlapped too closely the game gets confused as to which is producing more lift and that can make your aircraft turn as well.

[BamBam]

i was under the impression that the game considered overlapped wings as a single lift producing part.....

i did finally get one to fly a bit, but it is unstable and uncontrollable without asas turned on, and with it on it wont hardly turn at all...

plus i have the pitch trim maxxed out to keep the nose up.

[sal_vager]

That\'s a beautiful plane, you may need more lift at the front though.

The overlapping wing thing is from my own experience, I had a plane that would drift left or right at random and the game couldn\'t decide which wing to draw 'on top'

After I moved one pair of wings a few pixels in the SPH the problem vanished.

[Frostiken]

It\'s a little distressing, but canards are basically REQUIRED to make aircraft turn with any amount of urgency. Kind of disappointing in my eyes.

[BamBam]

That\'s a beautiful plane, you may need more lift at the front though.

The overlapping wing thing is from my own experience, I had a plane that would drift left or right at random and the game couldn\'t decide which wing to draw 'on top'

After I moved one pair of wings a few pixels in the SPH the problem vanished.

what about moving the wings forward? center of gravity change?

[hebdomad]

Ok here are a few tips that might help.

1. Landing gear location. This is surprisingly important. Think of your aircraft as one big sea-saw. If you put your rear wheels at the very back, it\'s going to be near impossible for the elevators to \'lever\' the nose up. The best location for your rear wheels is just behind your aircraft centre of lift (just behind the wings). It DOES mean you have a risk of destroying your tail if you get over excited with your take off, but that\'s an issue with real world aircraft too...

2. Keep your aircraft balanced. Unfortunately while burning fuel your weight will shift. As a rule of thumb, it\'s better to be nose heavy than tail heavy.

3. Don\'t bother with ailerons! but do put rudders and elevators on your aircraft. Your command module will roll fine without ailerons anyway and thanks to the code in KSP your \'elevators\' will also do the work of the ailerons for your...

And one last thing... Have a free jet fighter/stunt plane!

You might need a joystick or be really good with a keyboard to fly this jet, but it\'s a lot of fun

(SAS and hitting capslock is recommended!)

[rkman]

In my experience larger airplanes are more stable than small ones, and even large planes need only a minimum of control surfaces.

My most stable airplane so far has control surfaces only on the canard and the tail wings, none on the main wing.

[sal_vager]

Canards are just front mounted tail surfaces, I have a few planes with more conventional layout and canards only at the back, but C7\'s stuff does make combat jets too easy to make.

@BamBam, yeah that\'ll work, you\'ll move the center of lift as well so watch for that.

Btw I find rudders are not much use as they make craft roll in an unwanted fashion, but that\'s just my preference

[BamBam]

here is my other attempt

a bit easier to fly, still hard to get off the ground.

i will modify this later on with moving the wheels forward, and use bigger canards. maybe that will help

[JellyCubes]

You can try to attach the canards to your aircraft with a positive angle of attack in the space plane hanger to increase forward lift. Wings currently don\'t generate any lift with at zero AoA.

[MrMadGameplay]

One problem could be that you don\'t have the gears vertical or strait making the plane try and turn in all different directions, another thing I would was that If there wasn\'t some sort of vertical fin it tents to run around, another thing is if you have more that one nose gear.

One thing that helped me was, I made a dihedral wing which created a good amount of lift and helps to keep the plane stable.

(This is just my finding while playing)

[BamBam]

does anyone make a fuselage section that tapers upward like an airliner hull does in reality?

i like the c7 mk3 hull, but it either ends square or tapers downward at the tail.

[sal_vager]

You mean like the Mk3 to Mk2 adapter part?

[BamBam]

You mean like the Mk3 to Mk2 adapter part?

yeah, but that slopes down instead of up.

also, i moved the wing back and the engines/gear forward and this plane flies much better

[sal_vager]

Try rotating the adapter with WASD

I had trouble fitting the big 3M tank to it, but it fit after rotating it as well, then I had to remove and refit it the right way round so another adapter could fit on the back, it\'s weird it\'s like it wont assemble until it\'s been snapped on at least once.