tetryds

Official FAR Craft Repository

Recommended Posts

Only consideration for vertical tail is "does it control yaw even at high AoA" - especially if it's a spaceplane. For horizontal control surfaces for spaceplanes I'll always recommend canards - pitching up results in positive lift across all horizontal surfaces. This would be a typical design of mine. Forward sweep means there's a natural tendancy to roll into yaw, the engine-mounted winglets deal with that completely.

27683351284_ee809b7118_c.jpg

Demo ascent ( empty, but you can see it has masses of spare power ): https://www.youtube.com/watch?v=1RYGEBkrGBU

Drag-wise, a spaceplane is only hitting mach 4+ in very thin air so I've found it's actually not a big deal to have engines on the wingtips, never mind about shock cones. If you're building for RO earth and Mach 25 then I'm not sure why you're building a spaceplane, let alone a SSTO spaceplane.

Edited by Van Disaster

Share this post


Link to post
Share on other sites

The problem with canards and forward swept wings, is the bad re-entry heat/mechanical resistance. Canards will take a lot of heat being out of the shock cone, and fw swept wings will take a huge load out of the slightest AoA bump. I'd rather stick to standard tailless delta, even though these tend to have lawn dart behaviour...

Share this post


Link to post
Share on other sites
2 hours ago, Surefoot said:

The problem with canards and forward swept wings, is the bad re-entry heat/mechanical resistance. Canards will take a lot of heat being out of the shock cone, and fw swept wings will take a huge load out of the slightest AoA bump. I'd rather stick to standard tailless delta, even though these tend to have lawn dart behaviour...

We don't care about divergent issues - wings don't twist. I believe the shock cone at Mach 5 is 11 degrees, so those canards would be inside anyway ( since when did that matter for heating? ) - but that also doesn't matter if you don't aim at the planet like a lawn dart. In fact here's part 2 of the video covering re-entry - it being a new plane of course I messed up the descent & overshot the runway by several hundred km, but that was just a matter of sorting the timing out.

 

Edited by Van Disaster

Share this post


Link to post
Share on other sites

With Ferram, you can get more lift in the upper atmosphere at hypersonic speed, so heating is less of an issue because you stay out of it longer.    In the Gameplay Questions and Tutorials section,  there's a thread asking about re-entry angle and everyone is saying pitch up to 90 degrees radial out,  even though the OP was complaining about losing contro

The discussion then inevitably moves on to being unable to control landing point,   with folks coming down on the wrong continent and getting no recovery value on their expensive re-usable spaceplane.

I try to argue for a non-stalled re-entry angle but tend to get buried by the avalanche of "pitch 90 degrees" advice.     

Seems in this game, people handle re-entry in one of two ways

  • put pointy cockpit on very front (rather than inline), then re-enter on prograde hold because hey, capsules re-enter on retrograde right?  Then complain when it explodes
  • then come in at 90 degrees radial out, go into a flat spin, recover at 12km, land 4000km away from the space centre and get 29% recovery value.

 

1 hour ago, Van Disaster said:

We don't care about divergent issues - wings don't twist. I believe the shock cone at Mach 5 is 11 degrees, so those canards would be inside anyway ( since when did that matter for heating? ) - but that also doesn't matter if you don't aim at the planet like a lawn dart. In fact here's part 2 of the video covering re-entry - it being a new plane of course I messed up the descent & overshot the runway by several hundred km, but that was just a matter of sorting the timing out.

 

 

Share this post


Link to post
Share on other sites
1 hour ago, AeroGav said:

With Ferram, you can get more lift in the upper atmosphere at hypersonic speed, so heating is less of an issue because you stay out of it longer.    In the Gameplay Questions and Tutorials section,  there's a thread asking about re-entry angle and everyone is saying pitch up to 90 degrees radial out,  even though the OP was complaining about losing contro

The discussion then inevitably moves on to being unable to control landing point,   with folks coming down on the wrong continent and getting no recovery value on their expensive re-usable spaceplane.

I try to argue for a non-stalled re-entry angle but tend to get buried by the avalanche of "pitch 90 degrees" advice.     

Seems in this game, people handle re-entry in one of two ways

  • put pointy cockpit on very front (rather than inline), then re-enter on prograde hold because hey, capsules re-enter on retrograde right?  Then complain when it explodes
  • then come in at 90 degrees radial out, go into a flat spin, recover at 12km, land 4000km away from the space centre and get 29% recovery value.

 

 

Sarcasm aside I tend to re-enter at 30-50 degrees AOA depending on the plane, and make sure that my control surfaces aren't stalled even if parts of the main wing is. When it works it gives a lot of supersonic lift, and allows for shedding speed high up, and doing s turns if needed. 

I tend to land with empty tanks though which makes it easier. Currently I am trying to make an SSTO with low landing speed and land it on laythe with (almost) full tanks. It's proving quite hard and I'm leaning towards a supersonically optimised shape with RATO, or something like that ...

Share this post


Link to post
Share on other sites
19 hours ago, AeroGav said:

I try to argue for a non-stalled re-entry angle but tend to get buried by the avalanche of "pitch 90 degrees" advice.    

If you can persuade them to stay attached to the craft and then not pull whatever they're attached to off as well, rear-mounted stalled control surfaces are going to haul your speed down in a bit more of a hurry than mine did.

There was one version of FAR which involved making a descent by going twice around the planet in the atmosphere thanks to there being so little drag...

@plausseFor Laythe the easy answer is to land on the poles - other than that you can land in the sea, or it is actually doable to land on open ground but really not easy.

Edited by Van Disaster

Share this post


Link to post
Share on other sites

"If it looks right, it flies right." 

This is a pretty accurate (I like to think) replica of the Hakwer Hunter F. 1, with a custom AJE Avon engine. I was almost shocked to see how closely it performed to the real deal, which I suppose just shows you how powerful FAR is.

Spoiler

Screenshot19 by LythroA

Screenshot22 by LythroA

Screenshot23 by LythroA

Screenshot24 by LythroA

Screenshot25 by LythroA

Top Speed and Max Thrust, eerily close to the real deal.

I also made custom ADEN 30mm guns, they're a good laugh.

 

Share this post


Link to post
Share on other sites
On ‎11‎/‎10‎/‎2017 at 8:35 AM, AeroGav said:

I try to argue for a non-stalled re-entry angle but tend to get buried by the avalanche of "pitch 90 degrees" advice.

Today I succeeded in gliding Matt Lowne's Blunderbird 6 across half of Kerbin's circumference after botching my re-entry, and landed on the runway. Thanks to Gav's advice.

Folks, take his advice!

The aero data display in FAR helped a lot. I used that to maximize my lift-to-drag ratio on re-entry, and even with that pointy Mk1 cockpit managed to glide safely home.

Share this post


Link to post
Share on other sites
7 hours ago, Gordon Fecyk said:

Today I succeeded in gliding Matt Lowne's Blunderbird 6 across half of Kerbin's circumference after botching my re-entry, and landed on the runway. Thanks to Gav's advice.

Folks, take his advice!

The aero data display in FAR helped a lot. I used that to maximize my lift-to-drag ratio on re-entry, and even with that pointy Mk1 cockpit managed to glide safely home.

The simplest thing is probably just to fly by temperature, another thing a gentle re-entry will let you do. If the temperature is static but below maximum you can descend a bit faster, if it's going up too fast just pitch up & level off a bit  ( that requires a bit of pre-emption ). If you keep a note of the average descent rate you can plot a better trajectory for the next one until you can pick the right re-entry burn location & time, and the re-entry pitch, and basically just leave the craft alone until it's time to start flying & not just falling.

You don't actually want to maximise L/D - you're trying to slow down!

Edited by Van Disaster

Share this post


Link to post
Share on other sites

So, ah, this is a very British piece of engineering: landing speed of 73kts ( runs out of control authority just before it stalls ), stops in not much more than it's own length, can put it down about anywhere & takeoff run is pretty damn short too, but:

37681507134_d1e2dc9272_b.jpg

Anyone know of either any kneeling landing gear, or ramp extensions? :P I know you could use adjustable gear & change the strut extension, but that is pretty clonky & potentially quite destructive. Using extra gear & retracting the mains also works, but it's a really inelegant solution.

Share this post


Link to post
Share on other sites

You might, but just might, build some additional "footsteps" with IR parts, once you have landed, retract main landing gears and raise/lower whole craft trough IR extendratrons and "footsteps".

I say it might works because autostruts from landing gears can cause issues with IR parts, it can only be avoided with very careful placing of IR parts and stock landing gears.

I build something similar but much more overweighted in KSP 0.25 or KSP 0.90, cant recall exact version. Similar idea to yours, just to adjust rear tail ramp for rovers to get in and out.

Share this post


Link to post
Share on other sites

Hmm - I too have had bad experiences with IR & anything related to landing gear... will give it a little thought.

Modern aircraft parts seem to finally be light enough that you can use a sensible wing area & still get some decent performance. Hurray!

24530315218_8d1e0b1620_b.jpg
24530322408_68b718f938_b.jpg

That thing even has a Vr of about 90kts at sea level still

 

Share this post


Link to post
Share on other sites
On 14/11/2017 at 12:28 PM, Van Disaster said:

 

24530322408_68b718f938_b.jpg

That thing even has a Vr of about 90kts at sea level still

 

Never thought I'd see Dash 8 love here, haha

Share this post


Link to post
Share on other sites
4 hours ago, Nixod321 said:

Never thought I'd see Dash 8 love here, haha

Heh, well I live under the ( rather distant ) approach to our airport here - the carrier who's home it is is a pretty heavy Q400 user so I get buzzed a fair bit. There was a challenge last year involving shifting large numbers of Kerbals around so that gave an actual use for airliners & that thing's predecessor.

Also this nice looking thing

29365807124_fcba32183f_b.jpg

and this monstrosity too, so it was still very kerbal :P

38439021131_ed6ed702a9_b.jpg
38439020111_0560bbe5fd_b.jpg

Share this post


Link to post
Share on other sites

Did you put all those in there by hand? :P

One of the aircraft parts packs has a Mk3-sized BUFF cockpit, that'd go well on there. I think it's SXT, but I can't be sure.

Share this post


Link to post
Share on other sites

I actually kinda put them by hand.

The bug where if you mirror a part with mirrored childs doesn't mirror the mirror forced me to manually place both sides of the plates.

It was also a pain to set everything up properly and in a way that doesn't explode the airplane and since BDA did not have automatic fast bomb deployment it took ages to fire everything.

The wings are stock and so massive that they bended, aeroelasticity was so intense that rolling was null or inverted past a certain speed.

Things are much easier with a single huge procedural wing part :P

Share this post


Link to post
Share on other sites

Hm, think the wings are a bit off on that Scimitar, they had the same sweepback either side of the dogtooth. A bit of clipping on the engine tubes to shorten them too perhaps. Not a bad attempt though!

vickers_scimitar.gif

 

Share this post


Link to post
Share on other sites

Yeah he got the body / fuselage quite right, impressive. Getting the wings and elevators perfectly matched is a lot easier.

Edited by Surefoot

Share this post


Link to post
Share on other sites

@Van Disaster @Surefoot Thanks for the kind words guys! The length is dead on 14.8m, the length of the real thing itself. The wingspan I'm not too sure of, but I've fixed the leading edge sweep of the inboard wing piece.

The same could be said of this Hunter F. 1 here, the length is exact but I'm not too sure about the wings.

Spoiler

 

Screenshot26 by LythroA

Screenshot28 by LythroA

hunter-5.jpg

 

 

Share this post


Link to post
Share on other sites

@MightyDarkStarI'd pick a more developed Hunter model, the F.1 was terrible :P ( well the engines were pretty terrible ). The wing seems ok for that one, the air intakes might take a little reworking - that V shape is quite distinctive, not sure how to do it properly though. I made a vague attempt last year sometime but didn't really put much effort in:

Spoiler

26911498642_415d269686_b.jpg
26401857923_7efa7a91e0_b.jpg

As for the Scimitar & getting proportions right in general, you just need to see where things intersect with whatever you're scaling the model around ( in this case the fuselage ) - I annotated the drawing to show intersection points with the fuselage so you can align parts of the wing. The blue lines are on top of the leading/trailing edges, they're not offset at all. It'll also help you align the engines.

37600962075_c5c6942e56_b.jpg

Your tail needs a lot more sweep - think the current one looks more like an Skyhawk.

Edited by Van Disaster

Share this post


Link to post
Share on other sites
2 minutes ago, Van Disaster said:

@MightyDarkStarI'd pick a more developed Hunter model, the F.1 was terrible :P ( well the engines were pretty terrible ). The wing seems ok for that one, the air intakes might take a little reworking - that V shape is quite distinctive, not sure how to do it properly though. I made a vague attempt last year sometime but didn't really put much effort in:

  Hide contents

26911498642_415d269686_b.jpg
26401857923_7efa7a91e0_b.jpg

As for the Scimitar & getting proportions right in general, you just need to see where things intersect with whatever you're scaling the model around ( in this case the fuselage ) - I annotated the drawing to show intersection points with the fuselage so you can align parts of the wing. The blue lines are on top of the leading/trailing edges, they're not offset at all. It'll also help you align the engines.

37600962075_c5c6942e56_b.jpg

I was quite lazy with the Hunter and just threw the intakes on. I'll sort them tonight. I made a Vampire a while back that had quite nice intakes, made by completely removing the the leading edge on the wing root and using control surfaces and tweak-scaled fuselage pieces and a few intakes. I'll get a photo up soon.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.