Basic Aircraft Design - Explained Simply, With Pictures

[Fieel]

There is some videos in first post in FAR thread - check spoiler section. There is also link to FAR wiki. You may check Kerbodyne SSTO Division thread. I wrote some additional info in already mentioned thread in above post. Check spoiler sections.

You can find some decent craft examples for building with B9 and FAR.

When you open FAR graph hover mouse over numbers for tooltip with additional info. Don't know much about video tutorial, but you can start with mentioned. Hope that helps.

Thank you i'll look into it

[Wanderfound]

Is there a good tutorial video series that teaches FAR (i have no idea how to use it during construction!) and how to build some examples of basic planes using B9 and FAR?

kcs123 referred to these, but to be explicit:

Not video, but probably what you're after: http://s1378.photobucket.com/user/craigmotbey/Kerbal/Tutorials/Hangar%20to%20Landing/story

and:

(that's a stock aero vid, but it's a nice demo of how dihedral works)

Edited December 11, 2014 by Wanderfound

[MGCJerry]

Great tutorial. Really enjoyed reading it.

So I did what any Kerbal would do. Build and fly the Majestic Eagle craft... I had to add some struts though. As long as it doesn't wobble off the runway, it files ok with SAS. Landing... Lets not talk about that.

Craft file: http://2thextreme.org/downloads/Majestic_Eagle.craft (stock)

Edited December 13, 2014 by MGCJerry

[keptin]

Ha, I love it! That's the second majestic Eagle I've seen in this thread. It reminds me of the ultimate rule of aircraft design: With enough thrust, anything can fly!

[MGCJerry]

Heheheh, glad you liked it. Here's a link to my Majestic Eagle if anyone wants to crash fly it. I added the link to my post above too.

http://2thextreme.org/downloads/Majestic_Eagle.craft (Stock)

Also the more thrust you have, the faster it can disassemble, planned or not.

Edited December 13, 2014 by MGCJerry

[qoonpooka]

Adding to the praise here: The knowledge of both Kerbin aereodynamics and the terran 'model' is plain, the pics are charming, the explanations are useful and replicable. I'm now totally stoked to to go build some aircraft. The only thing I could wish for in a future edition is coverage of payload and fuel considerations. I know, e.g. that rocket fuel tanks are a waste because they pack oxidizer, so how do you build aircraft for longevity inflight, high-capacity hauling (for testing parts under certain conditions etc)... but I'm thrilled to have come upon this guide.

[keptin]

There may be an update in order post-aero update, which may be coming soon enough. It'd be great to include a section for payload and fuel mass, especially shifting fuel load. I'm sure plenty of folks run into the issue where their aircraft works great until fuel burn starts shifting the CoM and throws everything out of wack. Explaining why that happens and how to design around it or shift fuel in-flight would be helpful.

[eldiabs]

Have had no shortage of issues with NEAR and aircraft. After going through your awesome tutorial, I can finally design flyable and stable aircraft. Thanks!

[kcs123]

I just uploaded small design tutorial. You can find more stuff soon in my craft exchange thread. Link is in signature, here is imgur album that could help with plane designs.

Javascript is disabled. View full album

[B787_300]

Hey Keptin,

ready to update this with the new aero?

[keptin]

Time baring, hell yeah! Though it's going to take some time for me to familiarize myself with the new content. This is a basic guide, but I'm very excited to see how the aero update affects aircraft design in KSP in more advanced or subtle ways, e.g. mach wing sweep, etc.

[NARESH4444]

This guide is so good,when my father hijacked my laptop 2 days ago so he could find Aircraft Maintenance Basics for me to study before I go to college in two weeks time,he thought this was good enough to be added to that list.

[Huntn]

For the OP, I skimmed your tutorial, overall very nice.

I looked at the section on wings and have to clarify that if, as reported, the KSP airfoils produce no lift like an aircraft wing does at 0° AOA, but relies solely on "barn door" effect for lift, and in combination with the current physics, it seems like stalling at this point does not really apply. Please don't take this as a criticism of your guide, just an observation. In fact, from a flying standpoint, KSP should be categorized as an arcade flight model (at least in an atmosphere), however I am having fun in space, not that I've spent much time there but I am doing the tutorials.

Here is the question. I've googled some big wonderful looking Kerbal space planes and have to ask myself how much purpose do the wings really have other than adding mass? Granted I am new to the KSP, and I've been told new aerodynamic physics are coming which I'm looking forward to. But at this point, based on current physics, there seems to be little point to build something that looks like an airplane, but instead build something that looks more like a rocket with control surfaces attached. Thoughts? Thanks!

[kcs123]

Here is the question. I've googled some big wonderful looking Kerbal space planes and have to ask myself how much purpose do the wings really have other than adding mass? Granted I am new to the KSP, and I've been told new aerodynamic physics are coming which I'm looking forward to. But at this point, based on current physics, there seems to be little point to build something that looks like an airplane, but instead build something that looks more like a rocket with control surfaces attached. Thoughts? Thanks!

If you are looking for planes with huge wings, check links in my signatures for examples.

How much wing you need ? It depends a lot from design goal of your plane.

In space wing mass is just death weight, as you can't get lift from it in space. It will not be so much of dead weight in KSP 1.0 as there will be new wings that could be used as fuel storage too. Stock aero ? Pretty much as arcade flight model, for more realistic aerodinamic install FAR. Not perfect, but much closer to realistic aerodynamic physics.

For lifting heavy cargo in low orbit, plane with huge wings can be more efficient in comparison to rockets. In practical manner, additional wing surfaces weight half of mass compared to weight of air intake and engine weight that should produce same lift instead.

Try to look at payload efficiency chalange thread and compare results with rockets and planes with less wings.

Links in my signature also contains more info about design goals and flying path to orbit, to not spamm this thread with it.

[Huntn]

If you are looking for planes with huge wings, check links in my signatures for examples.

How much wing you need ? It depends a lot from design goal of your plane.

In space wing mass is just death weight, as you can't get lift from it in space. It will not be so much of dead weight in KSP 1.0 as there will be new wings that could be used as fuel storage too. Stock aero ? Pretty much as arcade flight model, for more realistic aerodinamic install FAR. Not perfect, but much closer to realistic aerodynamic physics.

For lifting heavy cargo in low orbit, plane with huge wings can be more efficient in comparison to rockets. In practical manner, additional wing surfaces weight half of mass compared to weight of air intake and engine weight that should produce same lift instead.

Try to look at payload efficiency chalange thread and compare results with rockets and planes with less wings.

Links in my signature also contains more info about design goals and flying path to orbit, to not spamm this thread with it.

Thanks for the info! I will do more research, especially the payload efficiency and fancy aircraft link you provided. As a pilot by profession, I'm just having a mental issue with planes designed using airfoils that provide ZERO lift, other than the barn door effect, lol. Now this is based on me hearing this in a video, not experimenting with them KSP wings. Technically I think these items in KSP qualify more as stabilizers or canards, but not wings, at least the type of wing on an airplane that always generate lift by virtue of moving through the airstream, and not relying on AOA to generate an upward force. However, obviously some lift generation is going on in the program whether it's from a realism standpoint or not. My goal is to work with what the program offers and hope as time passes, the physics become more realistic.

Ok, I've found the FAR Mod. Have you used it? Yes, I want more realism, but within the constraints of KSP, I want flyable aircraft or space planes. Does this mod effect just aircraft or both aircraft and rockets? If it makes aircraft more realistic to fly, a big thumbs up! But if it just makes them harder to fly, then maybe not (while acknowledging the more realistic= harder). Thanks!

Edited March 25, 2015 by Huntn

[kcs123]

Once I tried FAR it is difficult to me to play this game without it. Yes it effect both, aircrafts and rockets.

You will have find plenty of info in FAR thread what kind of things are calculated and what not. Somewhere in thread ferram have explained that lift from the shape of wing have more influence on subsonic speeds and very low influence on supersonic speeds.

On supersonic speeds more influence have AoA than shape of wing, what is upside of wing and what is downside of wing. Game engine don't calculate wing shape(upside/downside) as much as I am aware of. FAR mod work inside of gameengine limits and also disregards calculating some real life variables that have little influence in overall calculations. Also some of things requires too much CPU time to be calculated so those are not included too. Overall it is much closer to real life physics as game engine allows.

Again, it depends a lot of how you design your aircraft and what is your expectations of it. A lot of people use wings on space planes more as stabilizers or canards like you have already noticed. This design aproach is good for planes with TWR of 1.1 or above, it is good aproach for space travels between various SOI, but not so efficient for lifting stuff in orbit and back.

There is plenty posts in KSP forums with various design aproach, try some of them, think a little more about your own expectations and create your own planes. Once is assured, you will have plenty of fun doing both, reading forums, researching and making your own crafts.

[Maroco]

Great work, mate!

I noticed you taking about Ferram Aerospace Research. Now, designing planes with FAR is imensively harder than with the un-moded game physics...Do you know the Numbers? and if so, could you do a tutorial?

P.s: My aircraft tend to have a problem when it comes to maneuverability...When I pitch them up, or down, instead of turning smoothly in the shape of a circle, they they turn in little motions(swinging up and down).How can I stop this?

[kcs123]

Great work, mate!

I noticed you taking about Ferram Aerospace Research. Now, designing planes with FAR is imensively harder than with the un-moded game physics...Do you know the Numbers? and if so, could you do a tutorial?

P.s: My aircraft tend to have a problem when it comes to maneuverability...When I pitch them up, or down, instead of turning smoothly in the shape of a circle, they they turn in little motions(swinging up and down).How can I stop this?

There is no quick answer to this question, but problem you descibing is summed up on this picture, just need to understand graphs:

Each plane design is different, but most of them share common mistakes. So, thing that is happening with your craft design, so it start to wooble whenever you try to make loops by constant pitching up or down is that your overall control surfaces have too much control authority.

Meaning: when you keep key "S" pressed to pull up plane all time, your AoA becomes too large, so you have pushed plane in area where you start to loose lift and piching moment(yelow line) forces becomes much larger than forces from control surfaces that pitching plane up.

To handle this problem, lower pitching authority on control surfaces by one at a time until you are able to pitch up all times without falling in wooble effect. If you have gamepad ort joystick you can use analog controls in a way that you not reach maximum pitching. Without analog controlers you can use trim controls ALT + (W,S) keys on windows, or whatever "mod" key is on your OS.

If your pitching controls are already set on low, so lowering further will cause more issues than it solve problems then you have to adjust pitching moment(yelow line) in FAR graph to produce less force. It is described in other picture how to do it - by moving "fulcrum" or leverage on tail.

If you are looking for example, try Sporty Mk1 plane. This one is tuned for stunt maneuvers and it consist of all stock parts, so anyone can try it.

Open it in SPH to see how control surfaces were set to get a feel what you need to do with your own craft to make it better.

[keptin]

It's been two and a half years since I first posted this tutorial and we're hours away from getting the aero update many of us have dreamed of! I look forward to adding a few more sections to the tut as well as finally changing this...

If you have any recommendations for additions, post them below.

-Empennage design

-Fuel load in flight (change of CoM)

-Supersonic funtimes

-Update Control surfaces

-Update Drag section

Edited April 27, 2015 by keptin

[Alias72]

Here are a few suggestions for things that would have helped me out:

Mach tucking or why a plane is a lawn-dart beyond mach 2.

Ballistic Missile Defense. The relation between velocity and explosions in the atmosphere. (actual curves here would help)

Do a Barrel roll. Why aircraft that appear outwardly stable may in fact roll on their side and stall.

Re-entry for dummies and rocks. how to reenter the atmosphere without heat-shields and without fiery death.

Tailless aircraft stability. The REAL way to make a space-plane!

[ratchet freak]

Something else to add:

wing flex, it's what causes the control reversal on the stock albatross.

if a control surface on the trailing edge deflects upwards it cause the wing to rotate the trailing edge downwards this in turn causes a increase in angle of attack and can add lift (contrary to what should happen a decrease of lift)

[0235]

How much of this holds water with KSP 1.0? absolutely fantastic tutorial! i was almost there, but spending far too much time on trying to get centre of left bang on with centre of mass. absolutely fantastic tutorial! great effort

[NathanKell]

0235: except for wing aspect ratio and wing sweep, pretty much all of it does now. Dihedral/anhedral works properly, CoL above/below CoM, etc.

[0235]

0235: except for wing aspect ratio and wing sweep, pretty much all of it does now. Dihedral/anhedral works properly, CoL above/below CoM, etc.

Thankyou! its nice to see proper anheadral and dihedral working, can make some loony stable or unstable aircraft!

[MalfunctionM1Ke]

Keptin, are you actually working on an update for your tutorial?