VTOL Construction

[qoonpooka]

So I've got some EVA cluster missions far from KSC.  I'm playing with an absolutely brutal set of difficulty settings, and I'm getting bored with flying tourists around to scrape together enough cash to finance science missions.  I take the EVA and 'below' observation missions near KSC because they pay well for a 100% recoverable craft (aircraft) and they also give science while I'm at it (yay!)

For near EVA missions I use a build I call the 'Science Jetcar.'  It's a wingless aircraft with a pair of Junos and the basic landing gear, a low-science rover, basically. Great for scooting around @ 50m/sec.  

In addition to doing EVA missions on the opposite side of Kerbin, I'd like to get a 100% recoverable craft to some of the more distant biomes in KSP as well for science purposes.

 

Before 1.0 I would follow Scott Manley's VTOL construction video and basically build out a Harrier jet.  Is that build still viable? Are there any tips for building VTOLs with stock parts?  Any designs people want to share? I haven't finished unlocking all the 45 science point nodes yet, so it's vitally important that we do this with basic parts.

[steuben]

It's tricky with the 45s. I managed to cobble something together. It does about 100 mps, takes 8 junos to vertical off the runway, fly forward on 3. It has wings so it will fly which means I don't burn fuel the same way getting places.

[Val]

This craft isn't quite VTOL, but it's really close.

Let's call it VSTOL for Very Short TakeOff and Landing

[nascarlaser1]

22 minutes ago, Val said:

This craft isn't quite VTOL, but it's really close.

Let's call it VSTOL for Very Short TakeOff and Landing

your pics are messed up in the post :P.

Back on topic btw, my VTOL consist of a lander can, and 4 of the reliant liquid engines. It works best in the atmosphere, and can land safely using it's engines, or if you want distance you can you parachutes to land instead, but this would turn it into a vto.

[qoonpooka]

3 hours ago, nascarlaser1 said:

your pics are messed up in the post :P.

Back on topic btw, my VTOL consist of a lander can, and 4 of the reliant liquid engines. It works best in the atmosphere, and can land safely using it's engines, or if you want distance you can you parachutes to land instead, but this would turn it into a vto.

I like it a lot. I may go with that if I can't figure out how to build a truly VTOL craft. What's it's flank speed for point-to-point?

Edited September 14, 2016 by qoonpooka
Forgot the question

[Rocket In My Pocket]

VTOL's are pretty easy if you are willing to abuse reaction wheels. The biggest problem with KSP VTOL's is typically stability during the vertical portion of flight.

Just make sure the downward facing engines are either in line or equidistant to the COM. Rotating them so they face slightly out and away from the COM can provide more stability.

I usually follow a rule of 2:1 with VTOL's which is to say it typically takes 2 of an engine facing down to get 1 horizontal engine in the air. Ie. You'll usually need at least 2 Juno's providing vertical lift to get a single Juno providing forward thrust into the air. I'd provide some examples of small, early game VTOL's but I'm on my way out the door to work. Best of luck!

Edited September 14, 2016 by Rocket In My Pocket

[nascarlaser1]

17 hours ago, qoonpooka said:

I like it a lot. I may go with that if I can't figure out how to build a truly VTOL craft. What's it's flank speed for point-to-point?

I have no idea what you mean by flank speed for point to pint .

[qoonpooka]

28 minutes ago, nascarlaser1 said:

I have no idea what you mean by flank speed for point to pint .

When you're not in VTOL mode, and are instead in horizontal (or 'normal' or 'traditional') flight mode, what is it's highest sustainable ground speed at whatever it's optimum cruising altitude is?

[nascarlaser1]

12 minutes ago, qoonpooka said:

When you're not in VTOL mode, and are instead in horizontal (or 'normal' or 'traditional') flight mode, what is it's highest sustainable ground speed at whatever it's optimum cruising altitude is?

not sure. I think at around 300 m/s at about 1000 meters up. I fly it on an angle and I never bothered to look at speed/altitude :P. My motto is: if it gets the job done, keep it, no matter how poorly it does it.

[Baybrawler]

Bigger engines, look to real life examples for help. I love fighters so almost all my VTOL (attempts) are based of the f-35, if using stock you can just add 2 downward jets, and one forward one to simulate a rotating jet in the back. Using Throttle Controlled Avionics (TCA) is one of the best things for VTOL's, it makes them possible to fly without doing insane stunts in transitions especially. 

[Stoney3K]

As far as jet engines go, I've had my most success with a Panther engine as a lifting engine coupled with a Wheesley on top set to reverse thrust. The trick here is that jet engines have a CoM which is actually in front (or above) their actual mount, so putting a jet engine vertically will move the CoM up and make the craft less stable. So sticking two jet engines on top of each other in line with the CoM will not move the CoM anywhere up or down.

I usually map the 'Stage' action group to the Panther's dry/wet mode switch so you can get some additional upward thrust by tapping the space bar. Especially useful on takeoffs and landings and to sustain a certain altitude in hover.

[TheDestroyer111]

On 9/13/2016 at 7:36 PM, qoonpooka said:

So I've got some EVA cluster missions far from KSC.  I'm playing with an absolutely brutal set of difficulty settings, and I'm getting bored with flying tourists around to scrape together enough cash to finance science missions.  I take the EVA and 'below' observation missions near KSC because they pay well for a 100% recoverable craft (aircraft) and they also give science while I'm at it (yay!)

For near EVA missions I use a build I call the 'Science Jetcar.'  It's a wingless aircraft with a pair of Junos and the basic landing gear, a low-science rover, basically. Great for scooting around @ 50m/sec.  

In addition to doing EVA missions on the opposite side of Kerbin, I'd like to get a 100% recoverable craft to some of the more distant biomes in KSP as well for science purposes.

 

Before 1.0 I would follow Scott Manley's VTOL construction video and basically build out a Harrier jet.  Is that build still viable? Are there any tips for building VTOLs with stock parts?  Any designs people want to share? I haven't finished unlocking all the 45 science point nodes yet, so it's vitally important that we do this with basic parts.

Wow, you are a creative person. For survey contracts I use the simplest possible planes, so no VTOL at all, the craft i use for it are not even Very Short TO/L which is perfectly doable and probably the best way, as VTOL usually means either more drag/less speed with the same fuel use/less range or having to use rocket engines, which means adding special fuel tanks for them, which means you can hold less fuel for the jet engine used for horizontal flight. Also, i personally refrain from science missions until i get some serious technology, basically unlocking all the 45 science nodes. I deem the Juno engines too inefficient to use for flights around kerbin. But if you really want a VTOL (it could be used not only for science missions, if you have a war save then VTOL might be the only way to operate from an aircraft carrier)... Then I'll tell you what can be done. Another cool possibility is of course Very Short TO/L, but designing such crafts is similar to normal VTOL, just with smaller lifting engines, which allows weight saving and more efficient cruise, but TO/L is not entirely vertical.

If you have no problem in sacrificing some fuel tanks for jet engines, you can of course use rockets. Now, unfortunately in lower tech levels this means creating more drag as you don't have radial rockets available, so, in these terms it's not much different than having airbreathing lift engines. Rockets require additional mass in the form of rocket fuel tanks, while jets require more air intakes (because they need air even at low speed, where intakes are not so effective, however with juno engines it's not such a big problem as it's a turbojet and doesn't need the amount of air a turbofan needs). I personally prefer turbojet lifting engines, as they allow better fuel efficiency than rockets and use the same fuel (rocket fuel is heavy). Turbofans may be good lifting engines, but they spool up/down slowly, need a lot of air, and are just big. However, turbofans are good for larger VTOL aircraft or when you want to fly in VTOL mode for a longer period of time (such as for the recently popular type of craft, a "VTOL Turtle"). Once you get good radial rocket engines, they can give you low drag, but still at the cost of additional fuel tanks for them.

[Sharpy]

On 14.09.2016 at 9:28 PM, qoonpooka said:

When you're not in VTOL mode, and are instead in horizontal (or 'normal' or 'traditional') flight mode, what is it's highest sustainable ground speed at whatever it's optimum cruising altitude is?

Not really In naval, there's full ahead, which is the cruising speed, and flank speed ("speed used for flanking the enemy"), which is stressing the engines, wasting fuel but still not risking immediate damage to the engines - making them work at the edge of specs, as opposed to recommended parameters.

But I guess, here actually OP meant full speed - how fast you travel to the destination.

 

As for actual tip: Disable gimbal on the VTOL engines. If they are facing perpendicular to the cockpit (as they normally do) they are absolutely confused about what to do about 'pitch up'/'pitch down' and will flip your craft over presto, thwarting any attempts to right it through the reaction wheels or control surfaces. Alternatively, add a probe core facing the same direction they do (up) and 'control from here' to it before hover.

Edited September 19, 2016 by Sharpy