What is your fastest low altidue aircraft?

[katateochi]

How fast can you make a plane go at very low altitudes? by low altitudes I mean being at constant risk of clipping your wings on the ground if you bank to sharply.

I know you can get greater speeds higher up, but I'm looking for a more thrilling ride. So far I've only managed to fly at 150m/s a few meters above the ground, I'm sure some of you have designs that can do better. I'm also looking for good manoeuvrability too.

Do post pics of your fast low alt craft and any design tips are most welcome.

[Zalack]

This would be a good post for the Challenges section of the forum

[Torham234]

I did dabble in this kind of aircraft briefly before, but didn't get much result. I am more into the very long distance aircraft. This is one of my faster designs.

Codenamed Kraken, it can do around 210 m/s at sea level, and quickly picks up speed at higher altitudes. It has probably too much control surfaces, and can be tricky to fly without a joystick with the avionics switched off. With the avionics its rock solid though, no vibrations at all. The only downturn is very short range, as the 3 turbojet engines burn through the fuel at high speed.

[Mastodon]

I don't have any pics, but one day I decided to play around with planes that had solid rocket boosters attached (or, in the case of my fastest plane, as part of the aircraft). I hit about 300 m/s at an altitude around roughly 500-800 meters up. I got the mach effects and everything. plane was pretty stable too. I was able to turn around and fly back to KSC with the turbojet engine I had on it. and then crashed on the runway. those SRBs are heavy.

[XnuffX]

I did dabble in this kind of aircraft briefly before, but didn't get much result. I am more into the very long distance aircraft. This is one of my faster designs.

Codenamed Kraken, it can do around 210 m/s at sea level, and quickly picks up speed at higher altitudes. It has probably too much control surfaces, and can be tricky to fly without a joystick with the avionics switched off. With the avionics its rock solid though, no vibrations at all. The only downturn is very short range, as the 3 turbojet engines burn through the fuel at high speed.

is that a mod?

[katateochi]

That's a nice looking craft Torham234 and 210m/s ain't too bad. Would actually be interested to see your long range craft too. Low and fast is fun, but in the end long range is gonna be more useful.

[ROFLCopter64bit]

When I do a suboribital with a mainsail I like to burn prograde during re-entry, and get to excess of 1200m/s

[Van Disaster]

Not an area I've really gone into either, other than ground-skimming craft which can't really fly. Gave it a few goes - I use Ferram's aero mod so things are probably a bit different - and ran into horrendous stability problems, so ended up having to use Mechjeb. Still, some progress:

One air intake is *massively* more than you need at low level, you could probably run ten engines off it - FAR was reporting 1500% of required air. Likewise as the air density is so high you hardly need any lifting surfaces with that power/weight.

[Torham234]

is that a mod?

Nope, all stock.

This one did the Kerbal Circumnavigation challenge just before the forums imploded.

[katateochi]

This is my jet craft, it can do about 140-150m/s at low (ground scraping) alt, it's really manoeuvrable and seats 3. It has just enough range to get from the main KSC to KSC2 if flown at higher alt (~18km) but flames out above 20km.

This is the first aircraft I've built so it has some issues; It has 3 engines, but 2 are set higher than the centre of mass and lift so it wants to nose down too much. I can counter that with trimming but I guess that makes it less efficient. More learning required!!

[XnuffX]

I don`t have a screenshot but, my modded Aries 4A goes 250m/s+

[rryy]

I have a rocket-jet (which is supposed to be an SSTO) that can go near Mach 1 at low altitudes.

[Torham234]

Here is another one of my long range scouts, since you asked

Codename: Lark IV.

This is a long range stratospheric jet. It can attach 2 fuel tanks for even more range. With the fuel tanks it is very heavy though and the flight ceiling is around 15 - 16 km with top speed in around 650 m/s. Once the fuel tanks are jettisoned, the jet becomes much faster and can climb to 22 km with top speed in around 1100 m/s (when nearly full). I use this one for just exploring around Kerbal. It can land with ease, even on rough terrain, and of course take off again. However it can only take off from the runway with the fuel tanks attached, since it is very heavy and needs the full length of the runway to get airborn.

[Tanya Sapien]

I made a rocket plane that managed to hit around 500m/s at ocean-skimming altitudes, however I have Deadly Re-entry installed and the frictional heating combined with their own heat caused the rockets to explode before it could get any faster.

[Torham234]

I made a rocket plane that managed to hit around 500m/s at ocean-skimming altitudes, however I have Deadly Re-entry installed and the frictional heating combined with their own heat caused the rockets to explode before it could get any faster.

Love the sig

[katateochi]

I have a rocket-jet (which is supposed to be an SSTO) that can go near Mach 1 at low altitudes.

*snip*

That's a pretty nice looking craft too, thou 3000+m is higher than what I'm going for.

Here is another one of my long range scouts, since you asked

*snip*

that LR scout is pretty cool, what is it's range? I'm working on a Kerbin Explorer aircraft too, with a small rover that piggy backs on its roof. It can get about half way round Kerbin.

I made a rocket plane that managed to hit around 500m/s at ocean-skimming altitudes, however I have Deadly Re-entry installed and the frictional heating combined with their own heat caused the rockets to explode before it could get any faster.

nice! 500m/s at sea level, that's what I want! Do you think that is possible without rockets, only jet engines?

This is what I've got so far and I'm pretty pleased with it. The Screaming Gnat; fast(ish) 220m/s at ground scraping altitudes and pretty manoeuvrable too, which when you're skimming the ground is kinda important! (and it's got lazers).

Results from a short flight where I stayed below 500m and got up to 220ms.

It will go much faster if I pull up to a couple km but the point of this one is really to try and scare Jeb.

Are there any narrow canyons on Kerbin to fly in?

[Alephzorg]

If you want canyons, follow the rivers. The water is always at sea level, even as they go inland. And so the banks rise around it. Check the one north-east of the KSC.

[Torham234]

The range depends on how many landings you do, as it takes a decent amount of fuel to climb to the cruising speed.

On paper, The total range of jet is around 2050 km + another 900 km with the fuel tanks, so if you just fly in a straight line you could do somewhere in around 3000 km. The Circumference of Kerbin in 3769 km, so the jet can potentially fly 3/4 around the Kerbin.

[Vanamonde]

I just made this silly-looking thing.

It can hit around 250m/s at wavetop height,

but when I tried to cram more engines into the design, the speed increase was marginal while the control problems became atrocious. With 9 engines, it only just reached 280m/s, but could barely get off the ground and lurched around violently. There seems to be some kind of asymptotic speed limit for jets at low altitude, somewhere around 300m/s.

[katateochi]

If you want canyons, follow the rivers. The water is always at sea level, even as they go inland. And so the banks rise around it. Check the one north-east of the KSC.

cheers for that. Will check them out later.

The range depends on how many landings you do, as it takes a decent amount of fuel to climb to the cruising speed.

On paper, The total range of jet is around 2050 km + another 900 km with the fuel tanks, so if you just fly in a straight line you could do somewhere in around 3000 km. The Circumference of Kerbin in 3769 km, so the jet can potentially fly 3/4 around the Kerbin.

That's pretty good. I tested my explorer plane (which carries a small rover) and it was able to get almost half way round. Gonna have to set up re-fuelling points about the place. Never mind colonising space, I need to colonise Kerbin!

I just made this silly-looking thing.

It can hit around 250m/s at wavetop height,

but when I tried to cram more engines into the design, the speed increase was marginal while the control problems became atrocious. With 9 engines, it only just reached 280m/s, but could barely get off the ground and lurched around violently. There seems to be some kind of asymptotic speed limit for jets at low altitude, somewhere around 300m/s.

heh, darn, you beat my speed! nice 1. I think I will start a challenge when I get a mo. For max speed of a jet engine craft that you can fly for over 5 mins, staying below 500meters and then land back on the runway again.

[Yargnit]

I've actually done quite a bit of testing, and with an engine mass of roughly 97% total vessel weight you can hit mach 1 at sea level with Turbojets.

FYi if you're getting above about 300m/s at sea level with Basics, Turbojets will give you more speed, but burn fuel WAY faster.

[xclusiv8]

My fastest so far. It can go faster but for some reason parts start to fall of once I hit above 300m/s.

Edited April 24, 2013 by xclusiv8

[Van Disaster]

FAR/B9/Taverius' ( Taverius did the B9 FAR aero also ), nice clean design but about limits for FAR mod stuff. I haven't touched stock aero for months, sorry.

[Yargnit]

More details on what i said earlier:

I just went and made a successful Mach 1 at sea level capable Jet powered plane. (340.3m/s or greater at under 100m max altitude)

http://i.imgur.com/nfvS5vl.jpg

Stats:

• Total counted weight full fuel; 11.495t
  
• Total counted weight empty fuel; 11.095t
  
• Engine weight; 10.8t
  
• Launch engine weight fraction; .9395
  
• Final engine weight fraction; .9734
  
• Engine burn duration; 31 seconds @ max throttle
  
• Minimum take off velocity; 180m/s
  
• Velocity at end of runway; 295m/s
  
• Time to reach end of runway; 11 seconds
  
• Maximum velocity (under 100m altitude) 341m/s
  

Single stage, bare minimum parts except engines. All excess weight was trimmed, even including minimizing the number of wing surfaces and choosing the most weight efficient ones. Even different combinations of air intakes were played with to minimize intake drag. The number of engines was a fine tuning process also. 8 Turbojets doesn't provide quite enough thrust to reach Mach 1, and 10 run out of fuel before accelerating enough to reach it. (Also .5 intakes per engine + 1 is the most efficient ratio in terms of most thrust per intake drag) We're basically tuned to a razor fine point here. Fly it below about 85 meters and there's too much drag to reach Mach 1 before you're out of fuel. Fly it above 100 and it fails my "at sea level' requirement. And at Mach 1 you're above 97.3% of the planes total weight being dedicated to engines. (The only way to get faster is to raise this % and it's virtually impossible to do so any further)

Just tuning it to go from 339m/s to 341m/s top speed took several hours and a fairly major re-design. If anyone else is able to hit even 343m/s without ever breaking 100m max altitude via single-stage jet only I'd be crazy impressed.

[katateochi]

I've actually done quite a bit of testing, and with an engine mass of roughly 97% total vessel weight you can hit mach 1 at sea level with Turbojets.

FYi if you're getting above about 300m/s at sea level with Basics, Turbojets will give you more speed, but burn fuel WAY faster.

So I replaced the 3 basic jet engines on my Screaming Gnat plane with 3 turbo jet engines, result; catastrophically uncontrollable, top speed not determined.

I replaced the two side engines with turbo jets, leaving one basic in the middle. handled like an epileptic bee, top speed was no greater than before.

replaced just the central engine with a turbo jet, leaving two basics on either side; this I could fly, but it was still much less dexterous in its manoeuvrability and top speed was only increased by a few m/s.

So in the end I've gone back to the 3 basic engines because that seems to be a nice balance between fast and very very manoeuvrable.

My fastest so far. It can go faster but for some reason parts start to fall of once I hit above 300m/s.

nice! are you using the FAR mod?

FAR/B9/Taverius' ( Taverius did the B9 FAR aero also ), nice clean design but about limits for FAR mod stuff. I haven't touched stock aero for months, sorry.

I must give this FAR mod a go. I heard that is make some major changes to the game so I've been a little unsure if I wanted to use it. Is that motion blur being added by it?