How do I make reliable and functional jet VTOL aircraft?

[Tex]

So I've just been inspired recently, thinking about how awesome VTOL-esque spaceships and aircraft look and behave, and so I've wanted to try and get something like that just to mess around with in KSP. I've attempted to dissect the stock VTOL craft before, but it hasn't led me anywhere.

My development efforts today have resulted in bizarre asymmetric flameout issues that I simply don't understand and can't really explain well. So how does one make good VTOLs?

[dire]

Bear in mind that your standard rocket takes off vertically and lands horizontally.

I've made exactly one VTOL (I really wanted the science at the top of the VAB). I had various wheels and a cockpit on the center stack, then 3-symm a fuel tank, intake and Wheesley. This will take off and land vertically with loads of thrust, but landing takes a ton of practice -- I added chutes to mine and wound up blowing up half the time.

Your flameout issues are probably due to tilting your VTOL jets backwards to slow down. Just add some radial intakes pointing the wrong way and it should fix that.

[James Kerman]

I believe @cupcake is the VTOL master. 

https://www.youtube.com/user/CupcakesLanders

http://boardreader.com/thread/Cupcakes_Dropship_Dealership_6ievmxXl5s.html

Try looking there for some inspiration, mate.

Also the asymmetrical flameout issue is more than likely related to the intakes and how KSP "sees" them related to the engines.  If you have Kerbal Engineer Redux you can monitor air in while flying - you may not have enough intakes or one engine may be hogging them.

Edited August 19, 2016 by James Kerman
edited for more information

[Tex]

11 minutes ago, dire said:

Bear in mind that your standard rocket takes off vertically and lands horizontally.

I've made exactly one VTOL (I really wanted the science at the top of the VAB). I had various wheels and a cockpit on the center stack, then 3-symm a fuel tank, intake and Wheesley. This will take off and land vertically with loads of thrust, but landing takes a ton of practice -- I added chutes to mine and wound up blowing up half the time.

Your flameout issues are probably due to tilting your VTOL jets backwards to slow down. Just add some radial intakes pointing the wrong way and it should fix that.

Thanks a bunch, but my flameouts occur before my craft takes off. They flameout on the ground, and then flip over due to asymmetric thrust. The bizarre part is that they seem to increase in power normally for a while, then randomly cut out, become less efficient, cap their thrust, and that's it. The other engines work fine.

And thanks, @James Kerman, I'll check them out.

[dire]

You're not feeding your craft sufficient air for them to reach full power. You may be trying to use a hypersonic air feed, for example; if you add one or two air intakes with a high static speed you might have better luck.

Don't forget to also add radial intakes pointed in the wrong direction, otherwise when you're going (for example) exactly 40 meters per second and point retrograde your engines will suddenly die and you'll crash and burn.

 

A picture of your craft would be very helpful. I can't think of any situation where I've had that problem on takeoff unless I was spinning donuts on the runway.

Edited August 19, 2016 by dire

[Rath]

you are probably using the adjustable ramp intakes or whatever they are called now.  The hypersonic radials.

 

use the turbofan intake. or the big radial scoop.

[capi3101]

Going to post this link here. This is a spaceplane guide for an old - and I mean archaic at this point - version of KSP, but it does contain a section on how to build VTOLs and while many things have changed, the general principles still remain the same. In particular, I'd pay attention to how DocMoriarty suggests you go about testing the craft, especially before you try to do anything important with it.