Plane design tutorial

[samsa]

Hi,

speaking as a newbie in KSP, one thing I find terribly difficult is to design a working plane, despite the awesome videotutorials that can be found on the Internet. I think that a tutorial that teaches you how to build a plane would be a good improvement to the game: you would learn something useful about aerodynamics, and you would have a first plane prototype (built by yourself).

[Enceos]

This link has everything you need: http://forum.kerbalspaceprogram.com/threads/52080-Basic-Aircraft-Design-Explained-Simply-With-Pictures

[thereaverofdarkness]

samsa, your post makes it sound as though you have a plane design tutorial for us. But I have an idea: you're new, so you're not used to the old aerodynamics. We can help you get used to making planes in the new aerodynamics, and then I want you to write us a good tutorial from your newbie viewpoint, that will help some of the struggling vets to get used to the new system. Sound good? I'll go whip up some simple plane designs and show you the basics of flight.

[thereaverofdarkness]

Here's a very simple design that's very easy to make and to fly. I recommend Mk. 2 parts for beginning plane engineers, as they are both incredibly gorgeous and also very easy to use. Mk. 1 parts mesh well with 1.25m parts, but other than that they're actually more difficult to use and they seem more flimsy. But Mk. 3 parts are the most difficult to use, so don't start with those.

I put in some tutorials for how to use these. This was done with version 1.0.0.830. I've been hearing a lot of complaints that drag values were changed drastically in 1.0.1 or 1.0.2, so your experience may differ.

This design is simple and you should be able to follow it by the image:

Note how the center of mass (yellow) is ahead of the center of lift (blue). You want your center of lift anywhere between the center of mass and center of thrust (magenta). Placing the CoL close to the CoM gives you more control but makes the craft less stable, while placing the CoL far behind the CoM makes the craft difficult to turn, but it'll fly straight with little effort. Placing the CoL either forward of the CoM or behind the CoT will literally make the craft spin out of control and be unable to fly straight unless you brute force control it with RCS thrusters or something. You can check your centers with the three yellow-green buttons in the lower left.

Other things to watch out for: make sure you have air intakes, control surfaces, and landing gear.

I just threw on some radial intakes because we don't need anything major for low altitude flight. I also chose basic engines as they have plenty of thrust for our needs and in fact will help us stay alive by preventing us from going too fast. They're also extremely fuel efficient.

Now the control surfaces provide lift like wings do, but they also pivot which wings do not. Elevons are control surfaces, and the AV-R8 winglets pivot while the AV-T1 winglets do not. You can right-click the part to check if it has a lift rating or a control surface rating. You want lots of lift surface but some control surface too. You don't want only control surface, or your plane will turn too sharply. The way I made it is a good balance. I have lots of elevons on the back for lift power, and a pair of canards on the front for extra pitch control.

I just used basic small landing gear. I like to put one set on the front just under the nose (attached with radial symmetry on), and then a pair just under the wings at the back (attached with radial symmetry off). They're easy to place, they make the plane stable, and the front points up just a bit which makes it easier to get it off the runway. Pointing the plane up a bit is especially useful when you make a heavy plane or one with low engine power that struggles to get off the ground.

Once you have a plane you're satisfied with, toss it on the runway and let 'er go! Make sure to throttle all the way up for takeoff. Some people like to hold the brakes for a while to let the engines warm up, but I dislike this method because the game's sticky ground can sometimes throw the plane out of control once you start moving.

Takeoff!

With a plane this small and sturdy, and with the center of lift placed so well, you can do some fairly fancy flying. Don't get too crazy at high speeds, but you can flip sideways for fairly rapid turns:

Then just pull up:

Watch your navball. The orange -v- marker points toward your plane's facing, in the blue means your nose is above the horizon. The yellow circle with lines is your prograde marker, or heading marker, if that's in the blue it means you are gaining altitude. Maneuver it to the horizon to stay level in flight.

You can climb steeply, but watch your intake air:

If that gets too low, your engines will suffocate and flame-out. It's not usually catastrophic, but you can lose flight control until you fall far enough. The intake air amount is based on number of intakes, altitude, and airspeed. There seem to be other changes to the system I have not yet fully explored, so be prepared to not fully understand it at first. Let us know what you figure out!

You can come in for a landing pretty much anywhere you have a flat-ish space. Preferably you want level terrain without too many bumps, and a lot of open space ahead of you. If your plane is particularly large and glide-y, you may want an especially large amount of "runway" space to bleed off excess speed.

Nose down, but not too fast:

This plane can handle a pretty steep descent, but many planes will struggle more. Those white trailing bits are mach effects, signifying I am going above mach 1. Going too fast can heat up the plane, make it difficult to turn, or even make the engines struggle to run. This happened in this case because I am in a strong dive, normally this plane cannot go that fast. Also, the mach speed (speed of sound) is higher at higher altitudes, and this does affect the thrust of your engines in the new system.

Flare up when near the ground to bleed off excess speed, also turn off the engines at this point. Your wings are all you need for landing if your plane has enough control. Particularly dense planes, ie. carrying rocket fuel, may have to land under engine power.

Don't flare too hard--once again this plane can take it, but a plane with a lot of wing space that flies more gently also must turn more gently. If you are oriented too steeply toward the ground you may not be able to pull up in time. Make sure your landing gear is down. The foldable gear also come with a light, so if it's dark you can hit 'U' to turn that on. It'll let you see the ground when it gets close.

But for day, you can use your shadow to tell:

Glide until you're starting to have the first signs of losing ability to nose up. Don't glide too long or you might lose control, but you don't want to land going too fast either, so try to find a balance point you're comfortable with. Then ease 'er down. The prograde marker on the navball should be just below the horizon as you gently touch down.

Hit the brakes once you're on the ground. You can hold 'B', or just left-click the orange icon at the top to make them stay on.

Sometimes the ground is a little bumpy, and your plane may twist a bit during landing. Most cockpits can withstand around 45 m/s impact, however, so once you've had a few seconds to slow down you're probably fine. Any landing you can walk away from is a good landing, eh? (Losing wing bits is common on landing until you become more skilled. It's a thing I never mastered.)

This is a tutorial of what not to do. Flying too fast is way too easy with the new aerodynamics, if you do not have the new higher drag model. Just a few tips on what to avoid--and this is useful info even if you do have a version with higher drag. It's good to know what to look out for. For this part of the tutorial, I changed the plane's engines over to the TurboJet Engines. These have much higher maximum thrust, becoming exceptionally powerful at very high speeds.

When flying above the speed of sound for a given altitude, you can see these mach effects. As you continue to accelerate, they get stronger.

Strong mach effects! This plane is going very fast at low altitude.

If you go fast enough (which you'll notice most at higher altitudes), you can get this red effect, and this signifies a lot of heating on your hull-though there is heating from all flight so just because it's not red doesn't mean it won't explode!

When flying in the upper atmosphere, you may see only the red effect. Be careful not to let it take over your ship. The higher you are, the less strong the visual effect is before you explode.

Breaking 1000m/s at 12km altitude!? What were they thinking??

Edited May 5, 2015 by thereaverofdarkness

[samsa]

Enceos: yes, I have read this tutorial, and it's very interesting. But even with this, it's not easy to make a plane on your own, make it fly, and make it land, specially on career mode, where you don't have all the parts available. I mean a tutorial integrated in the game, like the ones that explain how to get to the Mun, for example.

thereacerofdarkness: that would be awesome. I think that the best tutorial would be inside the game itself, but a tutorial that is updated to the new aerodynamics would be also useful (most things I've found so far are a bit outdated). I will read these links and try to build something useful. If I succeed I will try to write an updated tutorial.

[samsa]

thereaverofdarkness, is it me, or your plane doesn't turn?

[thereaverofdarkness]

You don't want to just turn. To change your heading, you roll the plane sideways and pull up, like I did in the tutorial. Press Q or E to roll, and then press W to pull up.

If it's not working, make sure you have elevons and canards on like I put them on, and make sure you're not too high in the air. You should be able to turn easily under 10km altitude.

[Hunting.Targ]

I feel that Scott Manley's tutorial is all you need to get started (Reaver has posted plenty of links already, so I won't steal his thunder). Look it up on YouTube if you want.

Also, reaver, I find it interesting that you describe tutorials as spoilers. Do they spoil some game features, or do you think that a tutorial itself is a spoiler?

[Wanderfound]

"Spoiler" is just the standard way of hiding some text in a post; the forum itself adds the word "spoiler" to the link. Sometimes it's used for actually hiding spoilers, sometimes just to avoid cluttering up people's screens with a mountain of text (as is the case here).

See http://forum.kerbalspaceprogram.com/misc.php?do=bbcode for how to do spoilers and similar formatting tricks.

[thereaverofdarkness]

Yes, I used the spoiler function merely to hide the text. It's not intended to be secretive.