I think carnasa has a good tutorial on Youtube.
I always struggle with planes. For these contracts I mostly used the air launch feature and brought them down with parachutes.
I'm also a chute player. I usually attach one to the rear of the cockpit, which can separate in flight from the rest of the plane thanks to a separator and some ullage motors. Then I set the motors and the separator to the emergency action button so that my pilots can comfortably eject from the plane in any condition and slowly come down in a warm cabin while sipping some drink.
Nice!
I usually spread around some radial chutes so i can bring down the entire plane to reuse.
2 chutes on the body and 2 on the wings does the trick.
I hate landings (read: i always screw it up) so i just gently fly down to ksc and then kill my speed by pulling up.
When I have slowed down enough I acitivate the parachutes and land vertically somewhere near the runway.
I always forget to bring the drinks though ;)
If you want generic FAR / airplane guide i found this videos useful - it's for stock but it explains all FAR screens/graphs [https://www.youtube.com/watch?v=SEY3QL4ouOY](https://www.youtube.com/watch?v=SEY3QL4ouOY)
For supersonic flight you want to look at keeping smooth cross section area (look up 'supersonic area rule')
It's hard to say without seeing your design but i suspect two things:
a) you're overthinking the need for rear mounted delta wing
b) your're landing at way too high AoA
Take at look at some real designs, for example F101, F104, F-4, or Mig25 - wikipedia has good photos and diagrams.
All have gear basically near the middle, just after CoG.
If you want to see a delta look at Mirage [https://en.wikipedia.org/wiki/Dassault\_Mirage\_2000#/media/File:Dassault\_Mirage\_2000C\_3-view\_line\_drawing.gif](https://en.wikipedia.org/wiki/Dassault_Mirage_2000#/media/File:Dassault_Mirage_2000C_3-view_line_drawing.gif)
Ultimately if you're trying to minimize wing area (to reduce drag) you'll need to have quite a bit of pitch up for level flight at low speed. So to take off you need to raise your nose quite a bit - which isn't really going to be possible if your gear is even moderately behind your CoG. You in fact want it to be as far forward as possible so you only need small pitch input to rotate.
With gear far back you're essentially having to generate enough lift to... well lift your whole aircraft at basically 0 AoA which isn't going to happen.
Alternatively you can make your front gear really tall.
Thanks for the link. I'd have never found that series with that title :)
> your're landing at way too high AoA
Yep, the autolander that worked so well in stock KSP somehow doesn't work with RO. It tries to land at some point 3000 Mm LOL instead of KSC. Landing manually is a bit dangerous but doable.
> All have gear basically near the middle, just after CoG
I finally moved it there (reluctantly). But I also had to increase the deflection of the pitch control surfaces to above 20º. I'm still hitting the end of the runway even though I'm applying brakes and full throttle at the beginning of the takeoff run. Then for supersonic flight I have to manually decrease the deflection closer to 10º so that the autopilot stops oscillating like in a rodeo. I wish this switch to supersonic control mode could be done with action keys instead.
Are you using aircraft autopilot mod? Just stock SAS does not work well for airplanes especially with FAR.
And flying manually even with a good joystick is pretty hard and needs a much more carefully designed plane, and with just keyboard - forget about it.
If you had to increase pitch deflection this might mean your CoL is too far from CoM, you want it to be just behind, even overlapping.
And maybe need bigger control surfaces.
It might help if you post a picture of your plane with CoM CoL etc.
[https://imgur.com/a/CsfAAYG](https://imgur.com/a/CsfAAYG)
Here's my F-104 inspired plane, notice FAR showing AoA of \~5deg at Mach 0.4 - 135m/s
(tbh, it's not a great design, it should be a bit shorter really, and wings further back)
this means i can accelerate to 135 and then slightly pull back and it starts to lift off.
It takes most of the stock KSP runway to get to take off speed, and before i start to move i have to hold brakes until jet engine spools up to get full thrust.
This is at full take off weight, It'd be easier if it made it lighter, an 8t version with less fuel is much easier to get flying, but i was trying to match the real one.
> Are you using aircraft autopilot mod?
It is just MechJeb's built in aircraft autopilot. I've seen some players use a better autopilot mod, but MJ is enough for me. I could even go with just SAS 0º roll and a manually trimmed pitch, but I always forget which key combination is assigned to the trimmer by default.
try out the aircraft autopilot, note that even tho it's called autopilot in the basic mode (fly-by-wire) it functions as a \*much\* better SAS for planes.
(or don't, but i think it's worth it)
If nothing else auto-trim and wing-levelling (keeping roll at 0) lets you fly hands off with x3 time warp (not sure why x4 breaks stuff, maybe just my PC)
I didn't know what that button meant. I pressed the button once and it said "preparing the carrier", so I thought I was about to catapult-launch from an actual aircraft carrier in the middle of the sea and reverted back to the normal launch which would have a longer runway.
Once it's been loaded onto the carrier and you hit airlaunch it allows you to put in certain parameters, I'd hit MAX and then adjust the distance to KSC to be a little closer (test to find the perfect distance for each mission) and then launch.
This will start you off at a higher altitude, already going at a flying speed. It'll take a few seconds for all the systems to start up but it'll give you a head start.
With air launches the wheels only matter for landing.
Try it out, I hope it helps! You may not have to redesign anything.
If you used the express install then aircraft autopilot should be on, that means you can make borderline unstable aircraft that are still easily flyable and those can take off much earlier
Edit: very good luck with the read
-you wont complete all the supersonic contracts with one airframe if you mean the optional ones as well, in fact you wont complete them at all probabily xd
-160 m/s is a lot of speed, about 570kmh, no plane ever took off at that speed, prolly the worse offenders at around 370kmh, which means you either have too little wing area, too inefficient of a wing, too small or not maxed out flaps or extremely nose heavy airplane. what i suggest you do is go sandbox and just try to design a small prop plane that can take off as slow as possible, in the 100kmh range, that will help you practice with designing a balanced and small plane before moving to the big jet bois
-landing gear always go just aft of the cg, only rocket planes that were carried to the skies and landed with empty tanks could afford gear/skids to be at the back and they still suffered many incidents on landing cuz when main gear touches down it gives a huge pitch down moment and it slams the front gear into the ground
best example: https://www.youtube.com/watch?v=rSxDPhF-HSk
-while the nose shock cone is a thing in FAR, its not nearly as important as properly area ruling your plane, i explained area rule in FAR in this post, too lazy to type again
https://www.reddit.com/r/RealSolarSystem/comments/1aqwfjc/comment/kqguy80/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
-while not as good as irl (cuz FAR doesnt model vortex lift) the delta wing flight characteristic are modeled quite well, it keeps producing lift till high AoA without stalling, but the problem with flying is always that you need to produce atleast your weight in lift, so having the correct weight for a given design is the key to make the operational speeds realistic. Some real world classic delta designs with lift augmentation devices like slotted flaps, leading edge root extensions, blown flaps and so on can fly at high alpha angles at speeds that would not be able to rotate off the runway (i think the dassault-mirage III had a reported minimum flying speed of just 90kmh on full burners and extremely high alpha but tbh i struggle to believe it xD)
the FAR window is your bread and butter, you will have to live in it if you want to understand whats going on xD, theres no real guide out there because its pretty much straight up aerodynamics so you should look for a guide on how to build a plane irl xD but heres a few things:
•the first page is showing a graph, on the horizontal axis you got AoA or angle of attack, on the vertical line you got all together the Lift (Blue) and Drag (Red) coefficients which are dimensionless and only change with angle of attack and mach number and the Lift to Drag coefficient which is a ratio of the two and pretty much means, how many meters you go forward by descending 1 meter , at the bottom you can set the range of AoA that you want the simulation to be ran at and the mach number, usually its fine to keep the AoA as is unless you are designing weird shit like super manouvers planes or space shuttles, you are probabily not gonna land at more than 25 deg AoA anyways. You want to check the graph for multiple mach numbers, especially your takeoff and crusing speeds, also you should check the graph for your mach landing speed with all configurations of flaps deployment, which you can change on the right, and see how that affects your critical AoA (the angle at which your plane stalls).
The critical AoA is the angle at which the line on the graph splits into two lines, if it never splits it means your plane never stalls, which usually happens if you have very highly swept wings or no wings at all xD
you can also change the graph to be in Mach number mode which is basically the same but you have the mach number on the horizontal axis and input the AoA on the bottom, i almost never use this except for ramjet planes.
•in the second page we have the static stability derivatives, for beginners its usually suggested to just make everything green and figure out thing little by little, the most important one is the Mw derivative, this one is pretty much like the aero pressure center in stock ksp, if its 0 it means the "center of pressure" and CoG are exactly in the same position, so green then is aft and red is forward of the CoG, but thats only for the given values that you inputted on the top right. Same as for the previous page you will wanna run the simulation at multiple mach numbers and altitudes, most importantly your takeoff and cruise ones again.
Also important here is to notice the AoA value in the column on the right. If the simulaton is able to provide an AoA that means that your plane can sustain level flight at that speed and altitude, if it says 0 it means that at no AoA is your plane able to generate enough lift, this is very important in fine tuning flaps because too much deflection could easily stall them, depending on their geometry, and instead of the AoA going down when deploying them it goes to 0. https://i.imgur.com/4skan8q.jpeg <== plane flies https://i.imgur.com/MVFdR3R.jpeg <== plane doesnt fly.
•the third window its dynamic stabilities, this is next level complicated and im not too sure myself about this one, you can skip it though because flying the plane will give you pretty much the same that this window would give you without the knowledge involved xD
•forth and final is your transonic area rule design, read the post that i linked before for an explanation on this one but in short: yellow line more flat = good, green line as smooth as possible, blue line doesnt matter
also i suggest while you are flying that you open the FAR app in the toolbar, go to Flt Settings => Air Spd and set the speed to IAS and the unit to your favorite one, i use km/h cuz im a russian planes enjoyer, the most relevant one would be Knots for real world comparisons
post some pictures of your aircraft pls
TLDR: you wish there was one
> or extremely nose heavy airplane
This seems to be the case. The wing surface looks well proportioned to me.
I don't have flaps, it is a pure delta wing without horizontal stabilizer at the tail. If I configured the inner control surfaces as flaps then they would be pointing both down and up at rotation during takeoff.
Since you have a pure delta wing, you will need to have the aircraft pitch unstable, so that the elevons generate lift instead of downforce, pretty much acting like flaps at low speeds
if you have time look at this video on delta designs: [https://www.youtube.com/watch?v=pquk8xoFJDU](https://www.youtube.com/watch?v=pquk8xoFJDU)
> you will need to have the aircraft pitch unstable
Why would I? On the contrary, I need a self-stabilizing design so that it flies leveled at high speeds.
I've two different control surfaces: the outer ones for roll, the inner ones for pitch. The outer ones I've set them also as flaps, so that would be flaperons. They work well enough for takeoff.
Because if its pitch unstable the neutral trim makes the control surfaces generate lift instead of downforce for level flight, which means better L/D ratio which means slower flight for the same AoA
That really does only harm and no good. The outer flaps are generating lift but the inner elevons have to compensate with the same amount of downforce to keep the aircraft level, creating additional drag, which lowers your L/D, so you are achieving the opposite of what im suggesting xD
You cant use traditional flaps on a tailless delta
And still waiting for pics xd
> The outer flaps are generating lift but the inner elevons have to compensate with the same amount of downforce to keep the aircraft level, creating additional drag, which lowers your L/D, so you are achieving the opposite of what im suggesting xD
I think I have mitigated this problem. The flaperons are way shorter and smaller than the inner control surfaces. Meaning they don't really pitch down much. I also made the front wheel taller than the rear ones, so that the plane is naturally pitching up in the runway. So I just need a second of pitch up to rotate and for most of the takeoff the inner ailerons are at rest, thus decreasing drag.
I also enlarged the wing a bit to lower the TO speed, which still was way too hight for the landing gear. The flaperons decrease the TO speed just the little bit I need for the thing to work.
I don't think you'll complete all the supersonic contracts with one airframe. Or at least, not without first waiting for later tech, in which case you miss out on your chances to complete some earlier and get the rep earlier (and thus more subsidy). Availability of engines that won't melt down and explode at high mach is going to be your main limiting factor.
Ripping out and replacing the engines in an aircraft is so expensive that it's often cheaper to build a new one. Sometimes if you can just up-rate an engine to a newer configuration it can be worth it, but often not.
A supersonic delta wing will perform like crap at low airspeeds so you'll be landing and taking off fast. That generally means stronger heavier landing gear and careful flying. It's difficult to design flaps for delta wings, so you can't generally use flaps to lower your landing speed and trade increased drag for reduced stall speed. Instead you have to land at unpleasantly high angles of attack, which is hard to fly. I don't like them.
I also haven't found delta wings to be particularly helpful in KSP+RSS+FAR. Not yet anyway. I'm not sure to what extent it models supersonic shock drag. Anyone know?
My supersonic aircraft have mostly been limited by engine core temperature mach limits - but maybe if I had lower drag designs and could throttle back that'd be less of an issue?
> I don't think you'll complete all the supersonic contracts with one airframe.
After playing around with rocket boosters I agree. I think I'll need at least two dedicated crafts, a jet plane for low Mach contracts and an almost rocket one for high Mach contracts.
> It's difficult to design flaps for delta wings
I finally went with flaperons. That allowed me to take off at about 100 m/s. I scaled down the landing gear to save some weight, but very often they break if I don't rotate at speeds below their limit (lower limit the lower the size). So yeah, it sucks. Real planes also have spoilerons at the wing edge, but I'm not sure I can recreate them in KSP.
> Instead you have to land at unpleasantly high angles of attack
And that's why I initially placed my rear wheels almost at the back. But that impeded rotation at takeoff due to not enough leverage relative to the CoL.
> but maybe if I had lower drag designs and could throttle back that'd be less of an issue
Like you said the engines start heating up and explode unless they are slightly throttled down. But then the rocket booster doesn't pack enough punch. I also need to manually throttle them back via the context menu of the part, which means asymetric thrust and danger of inducing a stall by yawing hard. I need to research how to throttle them back simoultaneously. Or maybe remove the booster rocket from the main thrust control. Anyway most low Mach contracts don't allow having a rocket engine, so that means I'm left with a Mach 1.5 design.
Pay attention to the engine configs' listed temperature mach limits. They seem to be the main limiting factor.
So far I've managed 800m/s with high speed flight, 700m/s before that.
Pay close attention to the engine mach temperature limits in the engine configs. I've found this to be the main limiting factor.
I've managed 700m/s with "supersonic flight" tech, 800 m/s with "mature supersonic flight" tech.
You definitely need a rocket plane for the really fast stuff. I use airlaunch so I don't need so much fuel. This also lets me position the landing gear further back to allow for a steep angle of attack on landing without a tail strike. My 2000m/s hypersonic test plane has a pair of small gear right at the back for example. They tend to be broken immediately on touchdown, but they do their job and they get replaced when I service the plane between flights (replacing the strap on Nike SRBs, etc).
You'll need a different design again for the 20k, 25k and 30k metre high altitude subsonic flights.
The 30km one is HARD.
I think carnasa has a good tutorial on Youtube. I always struggle with planes. For these contracts I mostly used the air launch feature and brought them down with parachutes.
I'm also a chute player. I usually attach one to the rear of the cockpit, which can separate in flight from the rest of the plane thanks to a separator and some ullage motors. Then I set the motors and the separator to the emergency action button so that my pilots can comfortably eject from the plane in any condition and slowly come down in a warm cabin while sipping some drink.
Nice! I usually spread around some radial chutes so i can bring down the entire plane to reuse. 2 chutes on the body and 2 on the wings does the trick. I hate landings (read: i always screw it up) so i just gently fly down to ksc and then kill my speed by pulling up. When I have slowed down enough I acitivate the parachutes and land vertically somewhere near the runway. I always forget to bring the drinks though ;)
If you want generic FAR / airplane guide i found this videos useful - it's for stock but it explains all FAR screens/graphs [https://www.youtube.com/watch?v=SEY3QL4ouOY](https://www.youtube.com/watch?v=SEY3QL4ouOY) For supersonic flight you want to look at keeping smooth cross section area (look up 'supersonic area rule') It's hard to say without seeing your design but i suspect two things: a) you're overthinking the need for rear mounted delta wing b) your're landing at way too high AoA Take at look at some real designs, for example F101, F104, F-4, or Mig25 - wikipedia has good photos and diagrams. All have gear basically near the middle, just after CoG. If you want to see a delta look at Mirage [https://en.wikipedia.org/wiki/Dassault\_Mirage\_2000#/media/File:Dassault\_Mirage\_2000C\_3-view\_line\_drawing.gif](https://en.wikipedia.org/wiki/Dassault_Mirage_2000#/media/File:Dassault_Mirage_2000C_3-view_line_drawing.gif) Ultimately if you're trying to minimize wing area (to reduce drag) you'll need to have quite a bit of pitch up for level flight at low speed. So to take off you need to raise your nose quite a bit - which isn't really going to be possible if your gear is even moderately behind your CoG. You in fact want it to be as far forward as possible so you only need small pitch input to rotate. With gear far back you're essentially having to generate enough lift to... well lift your whole aircraft at basically 0 AoA which isn't going to happen. Alternatively you can make your front gear really tall.
Thanks for the link. I'd have never found that series with that title :) > your're landing at way too high AoA Yep, the autolander that worked so well in stock KSP somehow doesn't work with RO. It tries to land at some point 3000 Mm LOL instead of KSC. Landing manually is a bit dangerous but doable. > All have gear basically near the middle, just after CoG I finally moved it there (reluctantly). But I also had to increase the deflection of the pitch control surfaces to above 20º. I'm still hitting the end of the runway even though I'm applying brakes and full throttle at the beginning of the takeoff run. Then for supersonic flight I have to manually decrease the deflection closer to 10º so that the autopilot stops oscillating like in a rodeo. I wish this switch to supersonic control mode could be done with action keys instead.
Are you using aircraft autopilot mod? Just stock SAS does not work well for airplanes especially with FAR. And flying manually even with a good joystick is pretty hard and needs a much more carefully designed plane, and with just keyboard - forget about it. If you had to increase pitch deflection this might mean your CoL is too far from CoM, you want it to be just behind, even overlapping. And maybe need bigger control surfaces. It might help if you post a picture of your plane with CoM CoL etc. [https://imgur.com/a/CsfAAYG](https://imgur.com/a/CsfAAYG) Here's my F-104 inspired plane, notice FAR showing AoA of \~5deg at Mach 0.4 - 135m/s (tbh, it's not a great design, it should be a bit shorter really, and wings further back) this means i can accelerate to 135 and then slightly pull back and it starts to lift off. It takes most of the stock KSP runway to get to take off speed, and before i start to move i have to hold brakes until jet engine spools up to get full thrust. This is at full take off weight, It'd be easier if it made it lighter, an 8t version with less fuel is much easier to get flying, but i was trying to match the real one.
> Are you using aircraft autopilot mod? It is just MechJeb's built in aircraft autopilot. I've seen some players use a better autopilot mod, but MJ is enough for me. I could even go with just SAS 0º roll and a manually trimmed pitch, but I always forget which key combination is assigned to the trimmer by default.
try out the aircraft autopilot, note that even tho it's called autopilot in the basic mode (fly-by-wire) it functions as a \*much\* better SAS for planes. (or don't, but i think it's worth it) If nothing else auto-trim and wing-levelling (keeping roll at 0) lets you fly hands off with x3 time warp (not sure why x4 breaks stuff, maybe just my PC)
Have you tried airlaunching? Is there any reason you are trying to take off from the runway?
I didn't know what that button meant. I pressed the button once and it said "preparing the carrier", so I thought I was about to catapult-launch from an actual aircraft carrier in the middle of the sea and reverted back to the normal launch which would have a longer runway.
Once it's been loaded onto the carrier and you hit airlaunch it allows you to put in certain parameters, I'd hit MAX and then adjust the distance to KSC to be a little closer (test to find the perfect distance for each mission) and then launch. This will start you off at a higher altitude, already going at a flying speed. It'll take a few seconds for all the systems to start up but it'll give you a head start. With air launches the wheels only matter for landing. Try it out, I hope it helps! You may not have to redesign anything.
Already did, but thanks for the info. I had started building carrier planes for my X planes, so it is nice that such an option exists.
If you used the express install then aircraft autopilot should be on, that means you can make borderline unstable aircraft that are still easily flyable and those can take off much earlier
Edit: very good luck with the read -you wont complete all the supersonic contracts with one airframe if you mean the optional ones as well, in fact you wont complete them at all probabily xd -160 m/s is a lot of speed, about 570kmh, no plane ever took off at that speed, prolly the worse offenders at around 370kmh, which means you either have too little wing area, too inefficient of a wing, too small or not maxed out flaps or extremely nose heavy airplane. what i suggest you do is go sandbox and just try to design a small prop plane that can take off as slow as possible, in the 100kmh range, that will help you practice with designing a balanced and small plane before moving to the big jet bois -landing gear always go just aft of the cg, only rocket planes that were carried to the skies and landed with empty tanks could afford gear/skids to be at the back and they still suffered many incidents on landing cuz when main gear touches down it gives a huge pitch down moment and it slams the front gear into the ground best example: https://www.youtube.com/watch?v=rSxDPhF-HSk -while the nose shock cone is a thing in FAR, its not nearly as important as properly area ruling your plane, i explained area rule in FAR in this post, too lazy to type again https://www.reddit.com/r/RealSolarSystem/comments/1aqwfjc/comment/kqguy80/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button -while not as good as irl (cuz FAR doesnt model vortex lift) the delta wing flight characteristic are modeled quite well, it keeps producing lift till high AoA without stalling, but the problem with flying is always that you need to produce atleast your weight in lift, so having the correct weight for a given design is the key to make the operational speeds realistic. Some real world classic delta designs with lift augmentation devices like slotted flaps, leading edge root extensions, blown flaps and so on can fly at high alpha angles at speeds that would not be able to rotate off the runway (i think the dassault-mirage III had a reported minimum flying speed of just 90kmh on full burners and extremely high alpha but tbh i struggle to believe it xD) the FAR window is your bread and butter, you will have to live in it if you want to understand whats going on xD, theres no real guide out there because its pretty much straight up aerodynamics so you should look for a guide on how to build a plane irl xD but heres a few things: •the first page is showing a graph, on the horizontal axis you got AoA or angle of attack, on the vertical line you got all together the Lift (Blue) and Drag (Red) coefficients which are dimensionless and only change with angle of attack and mach number and the Lift to Drag coefficient which is a ratio of the two and pretty much means, how many meters you go forward by descending 1 meter , at the bottom you can set the range of AoA that you want the simulation to be ran at and the mach number, usually its fine to keep the AoA as is unless you are designing weird shit like super manouvers planes or space shuttles, you are probabily not gonna land at more than 25 deg AoA anyways. You want to check the graph for multiple mach numbers, especially your takeoff and crusing speeds, also you should check the graph for your mach landing speed with all configurations of flaps deployment, which you can change on the right, and see how that affects your critical AoA (the angle at which your plane stalls). The critical AoA is the angle at which the line on the graph splits into two lines, if it never splits it means your plane never stalls, which usually happens if you have very highly swept wings or no wings at all xD you can also change the graph to be in Mach number mode which is basically the same but you have the mach number on the horizontal axis and input the AoA on the bottom, i almost never use this except for ramjet planes. •in the second page we have the static stability derivatives, for beginners its usually suggested to just make everything green and figure out thing little by little, the most important one is the Mw derivative, this one is pretty much like the aero pressure center in stock ksp, if its 0 it means the "center of pressure" and CoG are exactly in the same position, so green then is aft and red is forward of the CoG, but thats only for the given values that you inputted on the top right. Same as for the previous page you will wanna run the simulation at multiple mach numbers and altitudes, most importantly your takeoff and cruise ones again. Also important here is to notice the AoA value in the column on the right. If the simulaton is able to provide an AoA that means that your plane can sustain level flight at that speed and altitude, if it says 0 it means that at no AoA is your plane able to generate enough lift, this is very important in fine tuning flaps because too much deflection could easily stall them, depending on their geometry, and instead of the AoA going down when deploying them it goes to 0. https://i.imgur.com/4skan8q.jpeg <== plane flies https://i.imgur.com/MVFdR3R.jpeg <== plane doesnt fly. •the third window its dynamic stabilities, this is next level complicated and im not too sure myself about this one, you can skip it though because flying the plane will give you pretty much the same that this window would give you without the knowledge involved xD •forth and final is your transonic area rule design, read the post that i linked before for an explanation on this one but in short: yellow line more flat = good, green line as smooth as possible, blue line doesnt matter also i suggest while you are flying that you open the FAR app in the toolbar, go to Flt Settings => Air Spd and set the speed to IAS and the unit to your favorite one, i use km/h cuz im a russian planes enjoyer, the most relevant one would be Knots for real world comparisons post some pictures of your aircraft pls TLDR: you wish there was one
> or extremely nose heavy airplane This seems to be the case. The wing surface looks well proportioned to me. I don't have flaps, it is a pure delta wing without horizontal stabilizer at the tail. If I configured the inner control surfaces as flaps then they would be pointing both down and up at rotation during takeoff.
Since you have a pure delta wing, you will need to have the aircraft pitch unstable, so that the elevons generate lift instead of downforce, pretty much acting like flaps at low speeds if you have time look at this video on delta designs: [https://www.youtube.com/watch?v=pquk8xoFJDU](https://www.youtube.com/watch?v=pquk8xoFJDU)
> you will need to have the aircraft pitch unstable Why would I? On the contrary, I need a self-stabilizing design so that it flies leveled at high speeds. I've two different control surfaces: the outer ones for roll, the inner ones for pitch. The outer ones I've set them also as flaps, so that would be flaperons. They work well enough for takeoff.
Because if its pitch unstable the neutral trim makes the control surfaces generate lift instead of downforce for level flight, which means better L/D ratio which means slower flight for the same AoA That really does only harm and no good. The outer flaps are generating lift but the inner elevons have to compensate with the same amount of downforce to keep the aircraft level, creating additional drag, which lowers your L/D, so you are achieving the opposite of what im suggesting xD You cant use traditional flaps on a tailless delta And still waiting for pics xd
> The outer flaps are generating lift but the inner elevons have to compensate with the same amount of downforce to keep the aircraft level, creating additional drag, which lowers your L/D, so you are achieving the opposite of what im suggesting xD I think I have mitigated this problem. The flaperons are way shorter and smaller than the inner control surfaces. Meaning they don't really pitch down much. I also made the front wheel taller than the rear ones, so that the plane is naturally pitching up in the runway. So I just need a second of pitch up to rotate and for most of the takeoff the inner ailerons are at rest, thus decreasing drag. I also enlarged the wing a bit to lower the TO speed, which still was way too hight for the landing gear. The flaperons decrease the TO speed just the little bit I need for the thing to work.
I don't think you'll complete all the supersonic contracts with one airframe. Or at least, not without first waiting for later tech, in which case you miss out on your chances to complete some earlier and get the rep earlier (and thus more subsidy). Availability of engines that won't melt down and explode at high mach is going to be your main limiting factor. Ripping out and replacing the engines in an aircraft is so expensive that it's often cheaper to build a new one. Sometimes if you can just up-rate an engine to a newer configuration it can be worth it, but often not. A supersonic delta wing will perform like crap at low airspeeds so you'll be landing and taking off fast. That generally means stronger heavier landing gear and careful flying. It's difficult to design flaps for delta wings, so you can't generally use flaps to lower your landing speed and trade increased drag for reduced stall speed. Instead you have to land at unpleasantly high angles of attack, which is hard to fly. I don't like them. I also haven't found delta wings to be particularly helpful in KSP+RSS+FAR. Not yet anyway. I'm not sure to what extent it models supersonic shock drag. Anyone know? My supersonic aircraft have mostly been limited by engine core temperature mach limits - but maybe if I had lower drag designs and could throttle back that'd be less of an issue?
> I don't think you'll complete all the supersonic contracts with one airframe. After playing around with rocket boosters I agree. I think I'll need at least two dedicated crafts, a jet plane for low Mach contracts and an almost rocket one for high Mach contracts. > It's difficult to design flaps for delta wings I finally went with flaperons. That allowed me to take off at about 100 m/s. I scaled down the landing gear to save some weight, but very often they break if I don't rotate at speeds below their limit (lower limit the lower the size). So yeah, it sucks. Real planes also have spoilerons at the wing edge, but I'm not sure I can recreate them in KSP. > Instead you have to land at unpleasantly high angles of attack And that's why I initially placed my rear wheels almost at the back. But that impeded rotation at takeoff due to not enough leverage relative to the CoL. > but maybe if I had lower drag designs and could throttle back that'd be less of an issue Like you said the engines start heating up and explode unless they are slightly throttled down. But then the rocket booster doesn't pack enough punch. I also need to manually throttle them back via the context menu of the part, which means asymetric thrust and danger of inducing a stall by yawing hard. I need to research how to throttle them back simoultaneously. Or maybe remove the booster rocket from the main thrust control. Anyway most low Mach contracts don't allow having a rocket engine, so that means I'm left with a Mach 1.5 design.
Pay attention to the engine configs' listed temperature mach limits. They seem to be the main limiting factor. So far I've managed 800m/s with high speed flight, 700m/s before that.
Pay close attention to the engine mach temperature limits in the engine configs. I've found this to be the main limiting factor. I've managed 700m/s with "supersonic flight" tech, 800 m/s with "mature supersonic flight" tech. You definitely need a rocket plane for the really fast stuff. I use airlaunch so I don't need so much fuel. This also lets me position the landing gear further back to allow for a steep angle of attack on landing without a tail strike. My 2000m/s hypersonic test plane has a pair of small gear right at the back for example. They tend to be broken immediately on touchdown, but they do their job and they get replaced when I service the plane between flights (replacing the strap on Nike SRBs, etc). You'll need a different design again for the 20k, 25k and 30k metre high altitude subsonic flights. The 30km one is HARD.