Naval Aviation Challenge

[Hotel26]

OK, you know I might as well get into the spirit of this thing: here's my entry, Firebrand...  It's 6.7 x 5.8m.  It's just a trainer jet for making touch-and-goes splats on carriers.

 

(Love your carrier, @Pds314!  What are her dimensions?)

Edited May 9, 2021 by Hotel26

[Pds314]

46 minutes ago, Hotel26 said:

OK, you know I might as well get into the spirit of this thing: here's my entry, Firebrand...  It's 6.7 x 5.8m.  It's just a trainer jet for making touch-and-goes splats on carriers.

 

(Love your carrier, @Pds314!  What are her dimensions?)

240 meters in length. 200 meters at the waterline. The craft is 39 meters wide with a maximum deck width of 19 Mk3 sidepanels, meaning in theory my Cipher jet should be able to land on it *horizontally.* The deck sits around 21 meters above the waterline, though it's slightly frontheavy so it's not perfectly level. I usually aim for 24-25 meters altitude at the end of an approach. The craft itself is IIRC 44 meters in height, but about half of that is the tower.

It's 600 parts and moderately laggy but still perfectly playable on my 8-year-old laptop.

Re: Splats.. Yup. Splattering craft on a carrier seems to be something I'm very good at as well. Fortunately at the speeds involved, damage to the carrier itself is very rare.

 

Despite her size, the carrier isn't all that heavy. I mean sure, 3900 tonnes isn't exactly light. It's bigger than a fully loaded Saturn V even though it's just hollow tanks, but considering even the lightest real carriers are easily 4 or 5 times that and some of the newer big American ones can be 25 times that at least. Like, considering that you could fit two Saturn V lined up on the deck and still have room for planes to take off beside them, the fact that it weighs only a bit more than one Saturn V is pretty light.

Edited May 9, 2021 by Pds314

[Hotel26]

20 minutes ago, Pds314 said:

Re: Splats.. Yup. Splattering craft on a carrier seems to be something I'm very good at as well. Fortunately at the speeds involved, damage to the carrier itself is very rare.

Best technique for me now seems to be to set an Outer Marker 5 km out and fly at 75m ASL at some speed about 10 m/s above stall (maybe +5 deg pitch) and then use a somewhat steep approach in the final moments, triggering the chutes when I see the whites of the ball boy's eyes...  I have the chutes attached about a meter behind the CoM, which means I can still flare just before hitting the deck.

Oh yeah, there's something else...  Umm.  Oh right: gear down at the OM and set the brakes at the same time! 

(Yamamoto, by comparison is 70 x 20m (74 parts).  It would need a crane to stack planes on the aft deck...  So, strictly: one visitor at a time.  )

Edited May 9, 2021 by Hotel26

[chadgaskerman]

Finally managed to figure out the wing structure of my new multirole carrier-borne aircraft

Folded, the dimensions are 11.3m long, 5.1m wide and 4.0m tall

Two variants, one powered by Rapiers with RCS and a docking port coming in at 19 tons and 49 parts, and the other by Panthers weighing in at 13 tons and 43 parts.

Once in orbit the SSTO variant has around 800-900m/s of DeltaV left, more than enough to rendezvous with a space station in LKO.

 

 

 

Edited May 9, 2021 by chadgaskerman

[Pds314]

53 minutes ago, chadgaskerman said:

Finally managed to figure out the wing structure of my new multirole carrier-borne aircraft

Folded, the dimensions are 11.3m long, 5.1m wide and 4.0m tall

Two variants, one powered by Rapiers with RCS and a docking port coming in at 19 tons and 49 parts, and the other by Panthers weighing in at 13 tons and 43 parts.

Once in orbit the SSTO variant has around 800-900m/s of DeltaV left, more than enough to rendezvous with a space station in LKO.

 

 

 

800-900 m/s is enough for Munar flybys or KTO.

[Pds314]

5 hours ago, Hotel26 said:

OK, you know I might as well get into the spirit of this thing: here's my entry, Firebrand...  It's 6.7 x 5.8m.  It's just a trainer jet for making touch-and-goes splats on carriers.

 

(Love your carrier, @Pds314!  What are her dimensions?)

I like the Firebrand's split Delta control surface design.

1 hour ago, chadgaskerman said:

Finally managed to figure out the wing structure of my new multirole carrier-borne aircraft

Folded, the dimensions are 11.3m long, 5.1m wide and 4.0m tall

Two variants, one powered by Rapiers with RCS and a docking port coming in at 19 tons and 49 parts, and the other by Panthers weighing in at 13 tons and 43 parts.

Once in orbit the SSTO variant has around 800-900m/s of DeltaV left, more than enough to rendezvous with a space station in LKO.

 

 

 

Wow 13 tonnes? What's the empty weight? Considering that the wings are slightly smaller than my Cypher and similar design other than the folding, that's got a pretty high wing loading compared to a lot of these aircraft.

Edited May 9, 2021 by Pds314

[chadgaskerman]

16 minutes ago, Pds314 said:

Wow 13 tonnes? What's the empty weight?

Around 7.6 tons empty

[swjr-swis]

Here's an entry built around a Juno power-plant. Somehow the 1.25m cross-section engines just seemed oversized for a plane of these dimensions, so I wanted to try something using Junos.

I don't have an easy way of deploying a carrier, so I did my STOL testing on the fueling chevron between the SPH and the runway.  It will take off and land within the distance from inside the chevron to the fall-off of that 'runway'. It maintains very high maneuverability down to a stall speed of less than 30 m/s, while being capable of circumnavigating on its default fuel load  at mach 1.8 @ 15km. Stowing dimensions of 8.5m x 6.5m x 2.7m.

 

Video added to demonstrate take off and landing:

 

Some teaser shots (full album  with more details linked below):

 

Full album: https://imgur.com/a/CS8Q2PQ

Craft file: https://kerbalx.com/swjr-swis/Arret-1N

Edited May 9, 2021 by swjr-swis
dimensions

[Mukita12]

I want took part in this challenge but like.... my Laptop cannot handle the high part count of a stock carrier. so yeah that's a shame

[swjr-swis]

1 hour ago, Mukita12 said:

I want took part in this challenge but like.... my Laptop cannot handle the high part count of a stock carrier. so yeah that's a shame

Please do! The planes are what matters in this challenge, not the carrier. You don't need to actually build or use a carrier to prove your planes' capabilities - you can use the section between the SPH and the runway as a replacement, like I did.

 

[chadgaskerman]

5 hours ago, Mukita12 said:

I want took part in this challenge but like.... my Laptop cannot handle the high part count of a stock carrier. so yeah that's a shame

give me a part count and i can work on an optimised carrier for you, all of mine are below 400 parts but that's for the crazy stuff

[chadgaskerman]

New awacs i'm working on

[Mukita12]

On 5/10/2021 at 5:50 PM, swjr-swis said:

Please do! The planes are what matters in this challenge, not the carrier. You don't need to actually build or use a carrier to prove your planes' capabilities - you can use the section between the SPH and the runway as a replacement, like I did.

 

Alright then

[Pds314]

On 5/10/2021 at 2:32 AM, Mukita12 said:

I want took part in this challenge but like.... my Laptop cannot handle the high part count of a stock carrier. so yeah that's a shame

A cheap way to do a carrier is 100 meters of floating tanks in the water. 4 tanks wide that's nearly an 8 meter wide landing strip and 40 parts. Also IDK how your laptop performs but mine is from 2013, that is, 8 years ago, and still handles 600 parts plus a 70 part plane with tolerable, though not realtime, lag.

Edited May 16, 2021 by Pds314

[swjr-swis]

I know this is about the aircraft... but since everyone else was getting their own carriers, I Jeb had to have one too. Besides, I needed something that would load and work in pure stock 1.3.1, and capable of launching from the runway.

Just the hull, flight deck, propulsion, and command island for now, enough to do some test runs. We'll get around to installing catapults, catch wires, elevators, and finishing the hangar.

How did they come up with Praying Mantis...?

Craft file: https://kerbalx.com/swjr-swis/SWiS-Carrier-I-Praying-Mantis

 

Valentina was immediately up for a test run in her brand-new Arret-1N.

 

Maybe she should've waited for morning...

 

Edited May 18, 2021 by swjr-swis
first runs... oops

[swjr-swis]

Looks like Valentina wasn't giving up for tonight, no siree!

 

"Wait, waaaaait! Not the Arret-1V! It's the only prototype!!!"

Val seems to be content to have made her getaway. Now for that carrier.

Easing it down on the deck....

Ha! Who's laughing now? With a prototype!

 

(craft file still not declassified)

 

 

[chadgaskerman]

I'm considering shifting the focus of this challenge from a more free form style to a contract style of challenge where contracts would be posted by myself and craft would be built to those specifications.

I'd like to here anyone's thoughts on this

[Hotel26]

6 hours ago, chadgaskerman said:

I'd like to here anyone's thoughts on this

Understanding what you are hoping to achieve with the challenge, this makes sense.  I'd suggest hybridization of the current format.  That is, you post various contracts as you choose, but without restriction.  If someone builds and submits a form of aircraft (role, purpose) "free-form" but that role appeals to you, you could formalize the type with a contract specification and then choose best-of-class submitted thereafter.  (A bit like some of the Airline Challenges.)  So, for example, someone submits a submarine-capable craft that is capable of being deployed from a carrier, or a cargo resupply plane that can land on a carrier; you respond with a contract specification; other interested parties submit craft in that category; you announce which one(s) you would select for your own fleet after enough entries are submitted in that class.

Edited May 24, 2021 by Hotel26

[chadgaskerman]

New foldy science Boi

Also updated the original post and created some contracts

[Samwise Potato]

My entry for Contract No.003A:

https://kerbalx.com/SamwisePotato/SA-Naval-Transport

In order to satisfy an open contract for a passenger aircraft capable of aircraft carrier landings and take-offs, Spud Armoury engineers got together in a dirty basement and played rock-paper-scissors to determine which poor sap was going to have to work on an airplane that didn't even have guns! Dudgee Kerman, expert engineer and terrible rock-paper-scissors player, was said poor sap. Sadly, he's not very good at naming things either; SA Naval Transport is about as original and exciting a name as he's ever come up with.

After getting mad and throwing a coffee mug at the rest of the engineering team, Dudgee gave the project as much of his attention as he felt it deserved and completely ignored it for the next three weeks. When the pilots who were scheduled to inspect the prototype and make test flights showed up, he sent them home and spent the day eating snacks in his office. Inspiration stuck late that afternoon, and Dudgee spent his evening and much of the night converting a passenger jet into a "naval" aircraft by chopping the wings in half and reconnecting them with a hinge, then adding thrust reversing to the engines. Job done, Dudgee fell asleep in the passenger cabin of his "new" creation and wound up being an unwilling passenger for the test flight in the morning.

Spoiler

Above: Wings folded

Below: Wings extended

Above: Landed on the VAB (Don't ask how many tries it took)

Below: Plane stowed dimensions and weight with full fuel load

As stipulated by the contract requirements:

- Part limit 70 (56, including some internal struts which could technically be removed if auto-strutting is allowed? I know some people think it's cheating, so I didn't want to assume.)
- Stall speed at least 65 m/s (Recommend 45m/s as minimum speed, risk of tail strike if landing any slower)
- carries 4-8 Kerbals (max 8 passengers and 1 pilot)
- range of 750km (1500km+ when properly handled, cruising altitude 8000 to 10000m)
- subsonic (in level flight, but a steep and lengthy dive under full engine power will break Mach 1. Throttle down as needed for safety.)
- stowed dimensions 12m by 6m by 4.5m or less (11.9 x 6 x 4.2)
- design based on Viking/Gannet/Tracker (folding wings mounted high on fuselage, engines under wings, cruciform tail)

This was, frankly, a frustrating aircraft to design. Since the plane was intended to resemble the Viking/Gannet/Tracker and be no more than 6m wide when stowed, a folding wing design was mandatory. I've never had a good time using DLC hinges, and this craft was no different. I would have preferred to have at least a Wing Connector B as the folding portion of the wing, but DLC hinges are so weak that a Wing Connector C was all it could support without risking wing failure while pitching up/down at speed. I've spent the last couple weeks tinkering with docking ports, pistons, and various stock hinge designs in an effort to create the aircraft I wanted, but keeping it under 70 parts ruled out most of the stock hinges I could come up with, and other solutions involved what I felt was an excessive amount of clipping.

Hopefully it's fairly obvious how the aircraft would also meet requirements for 003B by turning the rear two cabins into cargo space for science instruments and sticking a relay-capable antenna somewhere.

[Wizard Kerbal]

My re-purposed sea launch platform carrier is deployed 45 km away from KSC, i’m flying my plane now!

This challenge bests me.
My plane is too unwieldy at low speeds, and i’m bad with the throttle.

I realize now having the carrier moving would help significantly, but i’ve deleted both craft.

Edited June 25, 2021 by Wizard Kerbal

[chadgaskerman]

8 hours ago, Samwise Potato said:

My entry for Contract No.003A:

https://kerbalx.com/SamwisePotato/SA-Naval-Transport

In order to satisfy an open contract for a passenger aircraft capable of aircraft carrier landings and take-offs, Spud Armoury engineers got together in a dirty basement and played rock-paper-scissors to determine which poor sap was going to have to work on an airplane that didn't even have guns! Dudgee Kerman, expert engineer and terrible rock-paper-scissors player, was said poor sap. Sadly, he's not very good at naming things either; SA Naval Transport is about as original and exciting a name as he's ever come up with.

After getting mad and throwing a coffee mug at the rest of the engineering team, Dudgee gave the project as much of his attention as he felt it deserved and completely ignored it for the next three weeks. When the pilots who were scheduled to inspect the prototype and make test flights showed up, he sent them home and spent the day eating snacks in his office. Inspiration stuck late that afternoon, and Dudgee spent his evening and much of the night converting a passenger jet into a "naval" aircraft by chopping the wings in half and reconnecting them with a hinge, then adding thrust reversing to the engines. Job done, Dudgee fell asleep in the passenger cabin of his "new" creation and wound up being an unwilling passenger for the test flight in the morning.

  Reveal hidden contents

Above: Wings folded

Below: Wings extended

Above: Landed on the VAB (Don't ask how many tries it took)

Below: Plane stowed dimensions and weight with full fuel load

As stipulated by the contract requirements:

- Part limit 70 (56, including some internal struts which could technically be removed if auto-strutting is allowed? I know some people think it's cheating, so I didn't want to assume.)
- Stall speed at least 65 m/s (Recommend 45m/s as minimum speed, risk of tail strike if landing any slower)
- carries 4-8 Kerbals (max 8 passengers and 1 pilot)
- range of 750km (1500km+ when properly handled, cruising altitude 8000 to 10000m)
- subsonic (in level flight, but a steep and lengthy dive under full engine power will break Mach 1. Throttle down as needed for safety.)
- stowed dimensions 12m by 6m by 4.5m or less (11.9 x 6 x 4.2)
- design based on Viking/Gannet/Tracker (folding wings mounted high on fuselage, engines under wings, cruciform tail)

This was, frankly, a frustrating aircraft to design. Since the plane was intended to resemble the Viking/Gannet/Tracker and be no more than 6m wide when stowed, a folding wing design was mandatory. I've never had a good time using DLC hinges, and this craft was no different. I would have preferred to have at least a Wing Connector B as the folding portion of the wing, but DLC hinges are so weak that a Wing Connector C was all it could support without risking wing failure while pitching up/down at speed. I've spent the last couple weeks tinkering with docking ports, pistons, and various stock hinge designs in an effort to create the aircraft I wanted, but keeping it under 70 parts ruled out most of the stock hinges I could come up with, and other solutions involved what I felt was an excessive amount of clipping.

Hopefully it's fairly obvious how the aircraft would also meet requirements for 003B by turning the rear two cabins into cargo space for science instruments and sticking a relay-capable antenna somewhere.

Very nice entry, just the kind of design I was looking for.

yes, autostrut is allowed and encouraged, just make sure you don't autostrut the hinges else they won't work.

For improvements i'd suggest the following;

• Adapt the folding mechanism by rotating the hinge around 30 degrees back and then the wing piece back 30 so it's inline with the root of the wing - should allow you to squeeze a bit more wingspan and lower the stall speed. Personally I've found that the locked hinges are easily capable of handling +13/-13 G's when locked within reason, if they're supporting anything over 50 tons of lift they're gonna have issues.
• Maybe try experimenting with the "Big S" elevons as the elevator as opposed to the normal winglets. More wing area = lower stall speed and better handling.
• Try binding the leading edge control surfaces to deploy as high lift surfaces to make it even more controllable on final

[swjr-swis]

8 hours ago, Samwise Potato said:

This was, frankly, a frustrating aircraft to design. Since the plane was intended to resemble the Viking/Gannet/Tracker and be no more than 6m wide when stowed, a folding wing design was mandatory. I've never had a good time using DLC hinges, and this craft was no different. I would have preferred to have at least a Wing Connector B as the folding portion of the wing, but DLC hinges are so weak that a Wing Connector C was all it could support without risking wing failure while pitching up/down at speed.

You may have misunderstood a few of the listed requirements, making things unnecessarily difficult for yourself. The mentioned RL planes being mentioned 'for inspiration' is not meant to restrict to that particular visual appearance, just as examples. And autostruts are not considered cheating in challenges unless explicitly mentioned so (and I can't remember seeing a challenge that did).

I was curious about the limited speed of your plane for something powered by a twin Wheesley and looking very low-drag, so I braved loading up KSP on my currently pitiful non-play machine to try it out. There was a bit of obvious tweaking that could be done (adding some AoI on the wings for one), but basically what holds back your plane is the hinges: just the two hinges by themselves account for more than half of the total drag in flight, and it's enough to permanently lock it in subsonic state despite the available thrust.

So, I can't help the raw performance or the closely connected range of the plane much, but I did get the wings to be a lot more sturdy and reliable, and without the need for struts (auto or otherwise). Other than some normal bending at high G turns, it never once had any kind of breakage, even after pulling up to 15G turns and pull ups after dives.

The craft file, if you want to try it: https://www.dropbox.com/s/tozmmhpqscwio1m/SA - Naval Transport v4.craft?dl=0

It's yours to use as you see fit.

[Samwise Potato]

5 hours ago, chadgaskerman said:

[...] autostrut is allowed and encouraged [...]

Adapt the folding mechanism by rotating the hinge around 30 degrees back and then the wing piece back 30 so it's inline with the root of the wing - should allow you to squeeze a bit more wingspan and lower the stall speed. Personally I've found that the locked hinges are easily capable of handling +13/-13 G's when locked within reason, if they're supporting anything over 50 tons of lift they're gonna have issues.

Maybe try experimenting with the "Big S" elevons as the elevator as opposed to the normal winglets. More wing area = lower stall speed and better handling.

Try binding the leading edge control surfaces to deploy as high lift surfaces to make it even more controllable on final

I'll autostrut it and save on the part count if that's the case.

Rotating the hinge really wouldn't do much for the looks of the plane when the wings are folded, but I'll do some testing and see what kind of reduction in hinge flex it gives. There's no problems with space for folding the wings as-is even with a Connector B instead of a C, because I can simply remove symmetry on the hinges and fold one flat and the other to ~20 degrees to fold it over top if needed. Four and a half metres is plenty of height to work with, width is the only real challenge ('cause hinges are pain).

Edit: Rotating the hinge doesn't make the joint any stronger, and would require a fair bit of redesigning of the wing to meet size requirements when folded.

The AV-R8 Winglets were the outstanding pick visually, as they let me get a shape close to the S-2 and S-3 tails with only one part per elevator. Ideally I'd use a Tail Fin or Big-S 1, yes, but neither really match the way the plane needs to look.

Very true, I've already got the leading edge control surfaces for the sake of wing shape, and I'll happily set them up to do that, but none of the three crafts we're to draw design inspiration from had that capability. Can I stretch the design requirement that far, then?

5 hours ago, swjr-swis said:

[...] The mentioned RL planes being mentioned 'for inspiration' is not meant to restrict to that particular visual appearance, just as examples.

And autostruts are not considered cheating in challenges unless explicitly mentioned so (and I can't remember seeing a challenge that did).

[...] There was a bit of obvious tweaking that could be done (adding some AoI on the wings for one), but basically what holds back your plane is the hinges: just the two hinges by themselves account for more than half of the total drag in flight, and it's enough to permanently lock it in subsonic state despite the available thrust.

[...] I did get the wings to be a lot more sturdy and reliable, and without the need for struts (auto or otherwise). Other than some normal bending at high G turns, it never once had any kind of breakage, even after pulling up to 15G turns and pull ups after dives.

The planes were mentioned as part of the contract requirements, so I followed said requirements. If the contract author wants to change that, fine, but I'm not going to ignore contest rules as written. If I could though, I'd forget about hinged wings entirely and go for something far more effective, like a box-wing or vaguely diamond shaped wing that travels the entire length of the plane. Maybe even an oblique wing, or get fancy and use a rotor to turn an entire top-mounted wing segment. Max length 12m and max width 6m, so the stowed wing doesn't have to go perfectly straight forward and back; I could get 12.5 to 13m of wingspan depending on how chunky I'm making the wing.

Perhaps the dislike of autostrut is old and forgotten like the challenges autostrut was banned in (primarily in ones where being able to pull insane Gs without breaking big multi-part wings was a bonus IIRC), but I generally avoid advanced building options and limit clipping to being for the sake of aesthetics unless explicitly allowed, just to save myself the hassle.

A very good point I absolutely agree with. Your version is noticeably improved at cruising altitude thanks to the fine-tuned AoI. I'd wouldn't go with quite that much of an angle because I'd rather lose some of that speed to fix v4's tendency to pitch up when lining up landings, but you're 100% correct; even a small AoI change would make for an improvement. Sadly there's not much to be done about the hinges, as even your updated version suffers the same amount of drag and isn't breaking Mach 1 in level flight. The requirement was for a subsonic plane anyway, so it's no great loss.

I don't see how you've made the wings more sturdy or reliable at all: There were no struts on the wings in the first place, the wings now flex far more when pulling high G turns, and there was zero risk of breakage to begin with (pulling out of max speed dives was part of my testing process, and 95% of the reason I scrapped the longer wings). As for my struts, they were engine to fuselage bracing to help eat some of the force when making landings with low horizontal but relatively high vertical speeds.

 

Edited June 25, 2021 by Samwise Potato
Tested hinge rotation suggestion - no success

[chadgaskerman]

11 hours ago, Samwise Potato said:

Can I stretch the design requirement that far, then?

Yes, Inspiration is optional however i'd prefer it if they look within the realms of reality