Kerbal Express Airlines - Regional Jet Challenge (Reboot Continued)

[Box of Stardust]

So. I may have just created the best engine in terms of all-around stats. Just for testing purposes for now.

I got a bit tired of the Lotus's 220m/s cruise speed limit (darn thrust curves...), so I decided to look into... making alternatives again.

First, I tried Wheesleys, edited with 140% thrust limiters to bring them closer to Lotus thrust levels, since their stock thrust is kind of anemic compared to the Lotus, and wouldn't work as a replacement otherwise. It worked okay, actually. But I wanted better, both aesthetically and also in part count.

So I thought back to @neistridlar's 1.25m scale Goliaths. Except those output an incredibly pathetic 60kN of thrust. But since I've resorted to editing thrust limiters, that's a non-issue now, and I bumped it up to 270%, giving me a 162kN nominal thrust turbofan. Still lower than the 180kN of the Lotus... but I was feeling somewhat reasonable. Hey, if the Lotus of the same physical size puts out some crazy 180kN, then 160kN should be believable.

The aircraft pictured is an AX-502 Block 3 Variant B, weighing in at ~42t fully fueled on the runway and has about 2,400 kallons; it's identical in all ways to the A-502-1B except for the engines. But unlike the Block 1 A-502s (which will remain as TCAI Wave 2 entries) which don't meet the medium regional jet speed of 240m/s, this experimental Block 3 cruises at 250m/s at 7,400m at ~0.15 burn, keeping the same 4,000km range as the Block 1, but now fast enough to meet the class specification while running at ~85% throttle.

I call the engine the STRIDE; Scaled Thrust Range with Improved Dimensions and Efficiency. And I think it might be just fair, 'within the spirit of the challenge'.

 

Apparently, in a game where we get to go to space and get fancy high-thrust, high-speed, high-tech engines, all I want to do right now is build really good commercial airliners.

[TheFlyingKerman]

4 hours ago, Box of Stardust said:

I call the engine the STRIDE; Scaled Thrust Range with Improved Dimensions and Efficiency. And I think it might be just fair, 'within the spirit of the challenge'. 

This engine would be much better than the Wheesley in every way. That is unfair. If the thrust of two Wheesleys isn't enough (which I don't believe) just add more.

[HolidayTheLeek]

Thanks for the review! UCA has been waiting a while.

Something about the aircraft must've changed in an update when in storage for so long!t We at UCA don't actually remember the HC-2 actually being that stable. Though, that might be more likely because this craft was designed so long ago that we simply don't remember it's flight characteristics.

That comment about "fast speed" (230m/s) came from when UCA was a company that only really built propeller aircraft or very rarely, slow jet aircraft well, that was a shameless promotion lol. Back when we made prop aircraft only, 100m/s was considered fast, and having a takeoff speed more than 30m/s was considered high! We were also surprised the plane flew with one engine only; this was never intended in the design/

Anyway, the amount of aircraft ordered wasn't stated in the review. Is this a mistake? Sorry if I seem rude here.

 

1 minute ago, HolidayTheLeek said:

Thanks for the review! UCA has been waiting a while.

Something about the aircraft must've changed in an update when in storage for so long!t We at UCA don't actually remember the HC-2 actually being that stable. Though, that might be more likely because this craft was designed so long ago that we simply don't remember it's flight characteristics.

That comment about "fast speed" (230m/s) came from when UCA was a company that only really built propeller aircraft or very rarely, slow jet aircraft well, that was a shameless promotion lol. Back when we made prop aircraft only, 100m/s was considered fast, and having a takeoff speed more than 30m/s was considered high! We were also surprised the plane flew with one engine only; this was never intended in the design/

Anyway, the amount of aircraft ordered wasn't stated in the review. Is this a mistake? Sorry if I seem rude here.

 

this is referring to the review on the HC-2 by the way, I didn't realise there was a next page xD

 

[neistridlar]

8 hours ago, NightshineRecorralis said:

Hmm, is this a challenge for efficiency I smell? And Neist Air isn’t pursuing it? What world is this?

Neist Air isn't pursuing it?

 

5 hours ago, Box of Stardust said:

So I thought back to @neistridlar's 1.25m scale Goliaths. Except those output an incredibly pathetic 60kN of thrust. But since I've resorted to editing thrust limiters, that's a non-issue now, and I bumped it up to 270%, giving me a 162kN nominal thrust turbofan. Still lower than the 180kN of the Lotus... but I was feeling somewhat reasonable. Hey, if the Lotus of the same physical size puts out some crazy 180kN, then 160kN should be believable.

I see where you are coming from, but first of all, what does that engine cost? IIRC it is close to the Junos. Also, what does it weigh? The stats of the Lotus is basically just half of the Goliath, except with a nerfed thrust curve. They are too small for their performance, which gives a slight edge drag wise, but otherwise they are like a ~2m tweak-scaled Goliath IIRC. And besides the Lotuses are already extremely good in this challenge, the speed limit is really the only big drawback, removing it seems quite unfair.

1 hour ago, HolidayTheLeek said:

Anyway, the amount of aircraft ordered wasn't stated in the review. Is this a mistake? Sorry if I seem rude here.

@Box of Stardust See, the peoples want the numbers! Even if it is a bit random and inconsistent.

[Box of Stardust]

@TheFlyingKerman Of course it's better than Wheesleys! Even the uprated Wheesley was better than the standard Wheeseley! I'm an innovator! The airline market demands better performance for better cost-efficiency!

There's a fun story behind the name, actually. Like how we have the RAPIER for the SABRE in real life, I figured this new magic engine needed a good analogue too.

Since the J-56 'Lotus' is based on the CFM56, I essentially decided to come up with the equivalent of its successor, the CFM LEAP. Which apparently has technology from the GEnx engine, which itself was developed from the GE90, which here is the J-90 'Goliath'! And that's how I gave a smaller, very good performance Goliath a meaningful name.

@neistridlar You're right on the cost though, I forgot about that. Would be nice if I could figure out a way to bump up that price. It'd be way more acceptable if it cost more than a Lotus.

Also, I'll do the numbers if we can finally figure out that judging sheet.

Edited July 5, 2018 by Box of Stardust

[Mathrilord]

I'm going to create a mod that allow to create any engine ingame(rocket, jet, prop, car engine, ion, etc). The mod will work dividing engine in section each configurable ex;(for prop engine) propeller(s), blades, shaft, gear box,air intake(s), exhaust(s), engine(s)(piston, tuboprop, electric, rocket????). I need your help too find how to balance everything. (jet and prop)

Edited July 5, 2018 by Mathrilord

[MaverickSawyer]

59 minutes ago, Mathrilord said:

I'm going to create a mod that allow to create any engine ingame(rocket, jet, prop, car engine, ion, etc). The mod will work dividing engine in section each configurable ex;(for prop engine) propeller(s), blades, shaft, gear box,air intake(s), exhaust(s), engine(s)(piston, tuboprop, electric, rocket????). I need your help too find how to balance everything. (jet and prop)

This would probably be better asked in the "Addon Development" section.

[neistridlar]

2 hours ago, Mathrilord said:

I'm going to create a mod that allow to create any engine ingame(rocket, jet, prop, car engine, ion, etc). The mod will work dividing engine in section each configurable ex;(for prop engine) propeller(s), blades, shaft, gear box,air intake(s), exhaust(s), engine(s)(piston, tuboprop, electric, rocket????). I need your help too find how to balance everything. (jet and prop)

Like MaverickSawyer said. This is not the place for that kind of thing. If you are serious about doing it, make a WIP thread in the addon section (you can just follow the link in my sig for a quick shortcut there). Send me a PM if you need help with anything, I'll see what I can do.

[Box of Stardust]

Test Pilot Review: @neistridlar's NA Stout 168 & 216

A clear day for this deja vu... except these aren't really small but instead really big...

Figures as Tested (Stout 168, 168 passengers max):

• Price: 97,730,000 (empty)
• Fuel: 2,400 kallons
• Cruising speed: 218m/s
• Cruising altitude: 6,500m
• Fuel burn rate: 0.10kal/s
• Range:  5,100km (as calculated)

Figures as Tested (Stout 216, 216 passengers max):

• Price: 118,730,000 (empty)
• Fuel: 2,400 kallons
• Cruising speed: 215m/s
• Cruising altitude: 6,500m
• Fuel burn rate: 0.12kal/s
• Range: 4,200km (as calculated)

Review Notes:

It's another pair of Neist Aircraft Company planes for Twin Crown Aerospace to look at, with some case of deja vu to go along with it. Tubular fuselage with delta-like wings at the front and winglets at the wingtips. Seems like we've been here before. Except instead of being on the bottom end of aircraft size, these are on the opposite side of the spectrum.

Initial inspections resulted in judgements in line with expectations for NAC aircraft. Some concern was had over the very small tail controls, but we figured NAC knew what they were doing and decided they should be no cause of concern until proven otherwise. These were two very minimalist aircraft, with only the necessities to function present. Reasonable lengthy planes, before NAC jumped into their odd era of building really long skytrains.

With nothing else to really do except fly them, our test pilot got into the Stout 168 and put it on the runway. We expected everything to go by-the-book as outlined by NAC.

Takeoff was exactly that. Our test pilot pitched up as hard as possible to attempt a tail strike, but while the tail gets dangerously close to the ground, the Stout lifts off just before the tail actually hits. Wheels-up was achieved under 50m/s after a short takeoff run.

On the way up to cruise altitude, we conducted general maneuverability tests. This general flight dynamics test quickly revealed almost everything we needed to know about the Stout 168's flight dynamics. Stability is good, though we find that standard procedure is to fly with SAS turned on, as it has fairly relaxed stability, with sensitive control authority in all axes. Not that it's hard to fly without SAS, but just that it's easier to fly with SAS.

Cruise altitude was achieved in a reasonable amount of time, about 3-4 minutes. We attempted to attain cruise conditions through trimming the aircraft, but without SAS, the Stout was just too sensitive to hold solidly stable flight. With SAS, the Stout remained very firmly in cruising conditions. Cruise characteristics were as corroborated to be as outlined, resulting in the values presented in the quick specifications sheet.

With cruise testing over with, procedure led to engine failure testing. It passed the starboard engine failure test, remaining safely in control, though it is noticeably affected by the asymmetric thrust.

Next was full engine failure. Control authority in all axes remains strong. In fact, our daring test pilot, during this no-power state, decided to test the extreme control authority of the aircraft by pulling the aircraft into a vertical loop after a short, shallow dive, pulling up on the yoke with a speed under 200m/s.

So that happened.

But for the primary test condition, yes, the aircraft does glide well and retain speed well. These excellent low-speed and no-power characteristics meant that it also passed the emergency water landing test excellently.

The mid-speed and low-speed tests were done without SAS turned on. All these tests did were reaffirm everything we knew about its flight characteristics, with no fault found in them.

Landing, of course, was incredibly easy. Touchdown was made at ~44m/s, which we figure could be done at an even lower speed, and was a great end to an overall pleasant flight.

 

The Stout 216 was up next for testing. Like the Swirlygig, the longer Stout variant is a little heavier and sluggish on the pitch authority, but not significantly so.

Everything, again, went as expected and as outlined in the instructions, so we won't reiterate them. Control authority after complete loss of power was tested again.

Our test pilot, a military combat veteran, was a bit disappointed with the lack of post-stall maneuverability, but ground control reminded that they were in a 40t jumbo airliner, especially one with the engines currently shut down, then said nothing else. Anyways, the test pilot was so excited with ground control giving them clearance to do dumb things with the engines shut down, that they tried doing a barrel roll (yes, not just an aileron roll) after pulling out of a 230m/s dive at 1000m. Daring, but just not quite enough altitude, so the Stout 216 prototype hit the water at ~100m/s, at about a 10 degree angle of impact.

So we guess it's got a really good safety margin.

No matter, we figure Neist Aircraft will make back the money put into it through sales of the aircraft anyways.

With the second Stout 216 prototype (because of course prototypes come in multiples), we did the standard mid- and low-speed flight dynamics testing and found no new noteworthy data to report. Landing was again achieved at a very comfortable low speed of 40m/s with a shallow glide angle.

The last thing we really considered testing was ground handling, which is good with a remarkably small turning circle, and with the added benefit of a small wingspan to help it navigate tighter airports.

For logistics, the Stouts are simple aircraft with a part count on the low end for jumbo jets. They also have only two engines, which reduces maintenance time greatly, and keeps operating costs per-aircraft low. Range is fair to good, and they certainly get very good use out of their fuel load.

Criticisms? Well, there is one we could make. Like the Jupiter SST we've inspected, the Stout has a bit of oddness with its passenger amenities, though not critically compromising like it was in the Jupiter SST. But if we assume first/business class to be in the forward cabins, well, they're actually the ones with compromised downward views due to the wing design. And that's pretty much the only thing we could think of, if that's really a concern at all. Oh, and we suppose that, like the previously inspected HC-2 Country Hopper, some airbrakes might be a decent idea, though having working thrust reversers alleviates this issue as long as the engines are functional.

The Verdict:

Neist Aircraft Company's Stout series are excellent with no operational faults at all. The only thing we could comment on was regarding minor passenger amenities. Otherwise, they're easy to fly, easy to maintain, very safe, and on the lower end for initial buy-in cost. They're not fast, but, well, that's the Lotus engine that airliners should be familiarizing themselves with these days, until a faster alternative can be found with similar thrust and fuel efficiency.

The Stouts will make excellent mainstay fleet aircraft.

[TaRebelSheep]

What about the new mk3S1.5 parts from the AP+ update? There are no passenger modules that fit that size, so can we downscale a mk3 cabin and say it holds as much as a normal mk1 crew cabin?

[TaRebelSheep]

I just realised that there is a typo in the original post that I can't believe no-one has noticed yet.

It says " takeoff speed may be higher that 80 m/s"

Edited July 6, 2018 by TaRebelSheep
typo

[neistridlar]

2 hours ago, TaRebelSheep said:

What about the new mk3S1.5 parts from the AP+ update? There are no passenger modules that fit that size, so can we downscale a mk3 cabin and say it holds as much as a normal mk1 crew cabin?

Interesting proposal, though In general I think scaling crew parts is bad practice. Can you check the weight and cost? And how many passengers do you suppose that would hold? Also, I suppose you could just put chairs in the cargo bays and stuff (mind you the drag cubes and collides for those are currently not quite right). BlackHeart has stated that it is the intention to post more frequent updates, and more mk3S1.5 parts, so maybe just hold your horses for a bit.

And yes, the typo, I noticed it the first time around, and every time after that, just did not care to mention it.

[Mathrilord]

GO check here (sorry for pub :D)

 

 

[TaRebelSheep]

Two of my planes have been reviewed but have not been listed on the original post:

the C5 "RePurpose" on page 4, and the FA5T-W4 on page 10

Also, are you on the new thread in terms of reviewing planes yet?

[Box of Stardust]

1 hour ago, TaRebelSheep said:

Two of my planes have been reviewed but have not been listed on the original post:

the C5 "RePurpose" on page 4, and the FA5T-W4 on page 10

Also, are you on the new thread in terms of reviewing planes yet?

We don't list reviews on the main post anymore. We've all been working on a Google Sheets spreadsheet that all the reviewers have access to, so that it's not up to one person to do do the updating. The spreadsheet just hasn't been released to the general public for viewing yet, but that's the eventual plan.

[TheTripleAce3]

On 7/5/2018 at 11:29 PM, Box of Stardust said:

 

I'd love to see where the CG and CL are on this

[Box of Stardust]

11 minutes ago, TheTripleAce3 said:

I'd love to see where the CG and CL are on this

They're pretty much on top of each other. That's why it has sensitive control authority/'relaxed stability' and really good cruise characteristics.

However, it is still easy to control due to the distance of the control surfaces from the primary lift surfaces. 

The whole 'myth' of putting CoL behind CoM isn't really necessary. You just need proper placement of individual lift surfaces, rather than just looking at the CoL as a whole. 

In fact, go take a look at my A-503, and the CoL is actually ahead of the CoM, but it flies perfectly fine. 

[TheTripleAce3]

3 minutes ago, Box of Stardust said:

In fact, go take a look at my A-503, and the CoL is actually ahead of the CoM, but it flies perfectly fine. 

I just make my stuff conventionally bc its easier to fly imo

 

As for CoL in front... reaction wheels for days?

[Box of Stardust]

2 hours ago, TheTripleAce3 said:

I just make my stuff conventionally bc its easier to fly imo

 

As for CoL in front... reaction wheels for days?

Nope. A-503 is a medium jet entry for here. The aero is just designed properly. 

[TheTripleAce3]

9 minutes ago, Box of Stardust said:

Nope. A-503 is a medium jet entry for here. The aero is just designed properly. 

Does the fuel drain so the CG goes forwards?

[neistridlar]

2 hours ago, TheTripleAce3 said:

I just make my stuff conventionally bc its easier to fly imo

 

As for CoL in front... reaction wheels for days?

That is not necessary at all. There are two possible cases where the craft can be perfectly stable with CoL in front of CoM. If you have something really draggy at the tail, like a radiator or just no tail cone, that will help keep the plane flying straight, but it will not show up on the CoL. Second way is how My submissions work. If you check them your self you will find that they have no recation wheels at all, yet are perfectly stable and have the CoL practically on top of the CoM. As long as the forward lifting surfaces have a higher AoI than the more rearward surfaces the craft tends to be stable, and the relation between the CoM and CoL becomes more of a trim indicator, so having the CoL in front of CoM simply means the aircraft wants to pitch up.

Makes sense?

[TheTripleAce3]

1 minute ago, neistridlar said:

the relation between the CoM and CoL becomes more of a trim indicator, so having the CoL in front of CoM simply means the aircraft wants to pitch up.

I've always understood that but trim is for speed and going slow with a CL too far forward didn't work out for me XD

[Joseph Kerman]

Hey, is the previous list done? My jets are itching to be pulled out.

[neistridlar]

5 hours ago, Joseph Kerman said:

Hey, is the previous list done? My jets are itching to be pulled out.

Don't know what you mean by the previous list, but the oldest in the queue is currently from page 29 in the old thread, and there is something like 19 left from the old thread. If you really want to know how things are going, you could volunteer to fix up the judging spreadsheet so we can make it public .

[tonimark]

I would suggest Antonov an-12 with 48 passengers and mk2 viewer's cockpit in turboprop category note: sorry for the passenger cabins to be inside into cargo bay but its still visible from outside. shortcut keys 1.toggle engines 2.toggle reserver thrust 

link:https://www.dropbox.com/s/4p7a6tzxj40kemh/ANTONOV AN-12 (commercial usage) competiotion.craft?dl=0

SPECS: cruise altitude  7000 metres 

cruise speed 150 m/s

capacity:48 passengers 

fuel capacity: 24000 fuel units

cost:96093000 

distance: 11250 kilometres(calculated with fuel flow and tank capacity but I am not so sure)

fuel burn rate (cruise):0.32 fuel units (indicated at fuel flow as calculated)

caution: do landings very slightly touchdown and speed (otherwise your aircraft will break)

Edited July 17, 2018 by tonimark
fixing price