Aircraft

[Synapse]

Hey, I just made my first functional jet aircraft on KSP:

However I had some problems and noticed some things. I’ve searched and there doesn’t seem to be a very good definitive guide to these, so I was hoping to ask some questions and maybe we can develop one?

1. This design took me hours of spinning off the runway as per other forum users. Have we got a definitive answer for this? It is wheel placement? I’m sure my wheels were perfectly aligned on other designs – I don’t know why this one works and those didn’t.

2. CoL below CoM how can that be achieved with a standard engine body? Because if you lower your wings the wheels cannot function properly.

3. My jet peters out about 15,000 meters is that correct? How do I go higher besides using rocketry?

4. Intakes, what are the difference between the intakes? What is radial engine body for example? I though the aerospike was a jet engine apparently not? Some guidance on the parts would be helpful.

And yeah, general advice on making aircraft more stable, going higher etc. I'm not concerned with actual spaceplanes, but I would like a fighter jet capable of entering the upper atmosphere at least.

Edited July 15, 2013 by Synapse

[NoMrBond]

If you move the attachment point for your wings down on the body, and then rotate them flat using shift-WASDQE, that might do it?

Jet engines start to run out of air to burn fuel at higher altitudes, so more intakes can help in that regards (there are extremes though, usually called intakespam), but adding an engine nacelle and/or radial intakes to your engines can help go higher by providing more air at those heights

If you have something like the B9 pack, then those air intakes do actually function differently at different speeds, as for the stock parts I'm not so sure, the radial intake says it works better if you're going faster, but I'm not sure if there is much difference between the ram and circular excluding the ram intakes higher draw.

[koshelenkovv]

Hey, I just made my first functional jet aircraft on KSP:

However I had some problems and noticed some things. I’ve searched and there doesn’t seem to be a very good definitive guide to these, so I was hoping to ask some questions and maybe we can develop one?

1. This design took me hours of spinning off the runway as per other forum users. Have we got a definitive answer for this? It is wheel placement? I’m sure my wheels were perfectly aligned on other designs – I don’t know why this one works and those didn’t.

2. CoL below CoM how can that be achieved with a standard engine body? Because if you lower your wings the wheels cannot function properly.

3. My jet peters out about 15,000 meters is that correct? How do I go higher besides using rocketry?

4. Intakes, what are the difference between the intakes? What is radial engine body for example? I though the aerospike was a jet engine apparently not? Some guidance on the parts would be helpful.

And yeah, general advice on making aircraft more stable, going higher etc. I'm not concerned with actual spaceplanes, but I would like a fighter jet capable of entering the upper atmosphere at least.

1. Wheels must be perfectly vertical and aligned as much as possible (use Shift+WASDQE)

2. CoL must be behind CoM, but not much. CoL must remain behind CoM even when fuel gets used up.

It's better to align CoL, CoM and CoM in one line at lenghtwise axis, than place one below another.

3. You are using basic turbofan engine. It's intended for low altitude planes. Use turbojet and ram air intakes for high altitudes. For spaceplane use 3-4 ram intakes per engine, one engine per 4-5 tons (not counting engine itself).

Also, watch your "intake air" resource. If it drops below 0.10 (at full thrust), engine will flame out. So throttle it down to reduce air consumption.

4. Just use ram air intakes, they are light and most efficient. Air scoops are heavy. Engine bodies are cosmetic, they are very poor as intakes, suiting only for low altitude planes.

Also:

- toroidal aerospike rocket is rocket engine

- place intakes behind of CoM, or their drag will try to flip you over

- delta-deluxe winglet have very low steering capability. Replace it with tail fin and 1-2 small control surfaces or with ordinary AV-R8 winglet

- also, you can try dihedral or anhedral wings, but it's somewhat tricky to build self-stabilizing plane. It's easier to use ASAS or avionics pack.

Edited July 17, 2013 by koshelenkovv

[codepants]

This will help:

http://kerbalsource.wordpress.com/answers/#spaceplanebuilding

(edit: FYI, I only posted the link for the "more info" part of the question. I see the numbered questions have been answered above)

Edited July 17, 2013 by codepants