Help me with my spaceplane! I'm a noob!

[Olsson]

Introduction

Hello,

I\'ve landed at the moon using NovaPunch pack, done rockets, prototype explorers and I understand the basics and a little more of building rockets. I\'ve got more to learn buildings rockets such as more advanced techniques and optimizations. Though at building space planes, I\'m a complete noob.

Problem

So I\'ve made my first space plane, made for atmospherical flights. The goal is to build a plane going up to 12km, detach a rocket/plane which gets me out into space and then get down from space and land. I started with the last stage, the landing part of the aircraft. I guess it should be smaller than what it actually is but before I can get into such a project I need to learn a few things. I made an aircraft which has a hard time lifting up at take off for some reason, it tilts down (top heavy I guess?) and the design might be inefficient. Also I would like to know a few things about basic aerodynamics such as what do delta wings do, should they be at front or rear? How wide should the aircraft be and how long? What are the difference between swept wing and delta wings?

[RC1062]

You say it tilts down? That suggests an difference in position between the centre of mass and centre of lift (Eg move your wings forward or move the mass backwards).

In real life delta wings are used for super sonic craft whereas normal wings are used for subsonic craft (Drag alters a lot after Mach 1).

Craft with delta wings generally have the wings back, but canards at the front. The position of the lift is pulled forwards by the lift from the canards.

Craft with normal wings have their wings forward, but have stabilisers at the rear which pulls the center of lift back.

Hope this helps.

[Olsson]

You say it tilts down? That suggests an difference in position between the centre of mass and centre of lift (Eg move your wings forward or move the mass backwards).

In real life delta wings are used for super sonic craft whereas normal wings are used for subsonic craft (Drag alters a lot after Mach 1).

Craft with delta wings generally have the wings back, but canards at the front. The position of the lift is pulled forwards by the lift from the canards.

Craft with normal wings have their wings forward, but have stabilisers at the rear which pulls the center of lift back.

Hope this helps.

So this means that it\'s better to have a delta wing aircraft at higher speeds since it will be more stable? And this also means that if I have front heavy aircraft I should have delta wing? Also what are canards, are they the control surfaces such as 'advanced canards'?

[RC1062]

Canards are just small wings on the front of the plane. The fin under the control tab, yes.

I don\'t think wing shape makes much difference to the drag currently.

If you have a front heavy craft the centre of mass will be forward, so you need to increase lift at the front to move the centre of lift aswell.

[Olsson]

Canards are just small wings on the front of the plane. The fin under the control tab, yes.

I don\'t think wing shape makes much difference to the drag currently.

If you have a front heavy craft the centre of mass will be forward, so you need to increase lift at the front to move the centre of lift aswell.

Right so I did some adjustments. Moved more weight back and added canards to the front, even if I add three canards it won\'t make a difference. What\'s wrong with my design?

http://i.imgur.com/idi11.jpg

This might not actually be what the finished product is like I just want to understand how to balance crafts n shit first.

[RC1062]

Ooh... Your back wings are very far back. Try moving them 1/3 forward.

[Olsson]

Ooh... Your back wings are very far back. Try moving them 1/3 forward.

No effect

http://i.imgur.com/1Jsnj.jpg

[RC1062]

What is it doing on launch?

[Olsson]

What is it doing on launch?

Well it takes off fine, goes kind of straight so to speak. When I hold S to lift off it bounces abit up and down and when I get a straight heading the nose starts tilting down.

EDIT: It flyes and stuff and if I turn on SAS it flies straight but the thing is I want it to hold a straight course and be balanced without SAS if you get my point.

EDIT2: It doesn\'t matter what I do, if I put more weight at the rear, make the aircraft longer/shorter, make it lighter in the front, move wings back and forth. Nothing makes the plane tip forward. Anyone please!

[G Addict]

You\'ll never get a plane that always flies level without SAS - as fuel drains the centre of mass will also change and throw off your balance. Use SAS for normal flight, to lock your plane into its heading. When you want to turn, turn SAS off, roll SLIGHTLY in the direction you want to turn, then pull up a little. Don\'t touch the rudder, as a rule.

Planes are usually more balanced and well-behaved if you have a very large overall wing area, since wings help redirect your movement as well as generate lift.

[Kryten]

You\'ll want a vertical stabiliser and rudder on that thing if you want to turn it at all controllably.

[vexx32]

Planes will not be able to turn mid-air with a rudder. They\'re best turned with roll and pitch controls instead. Trying to use a rudder will, in most cases, either destabilise the flight path or cause the plane to break up. You\'re basically forcing the plane to be at an unnatural angle to air flow, which (although not entirely simulated perfectly) will often cause the plane to be subject to unnecessary extra stress.

[Xivios]

No effect

http://i.imgur.com/1Jsnj.jpg

You made the fuselage smaller but the wings are still on the very ass end of the plane. Trying leaving it longer, moving the wings further ahead, and adding a conventional tailplane, minus the rudder (but including the vertical stab)

Rudders are a good idea in theory but KSP\'s current way of deciding if a flight control surface reacts to an input or not makes their use very difficult, because they almost always fight the player when rolling the plan, when a player tries to roll right, a rudder will try to yaw left, and vise versa.

[Zephram Kerman]

Re: the comments about rudders and turning, please think of it this way: an airplane does not turn like a car (nor a rocket). An airplane uses lift to turn. Yes, that is not a typo.

If you want to turn, roll (aka 'bank') in the direction you want, and then pull back to pitch in that direction. This doesn\'t change the direction of travel, but it does rotate the airplane. The increased angle causes your wing lift to change the actual direction of travel.

In short form, 'bank and yank'.