Kerbal Express Airlines - Regional Jet Challenge (Reboot Continued)

[Andetch]

With enough yaw authority a single engine on one side should be okay...... At least, that's what we tell ourselves here because we don't like doing recalls and that may mean bad news for my NestRider....... No hurry though, probably got until the end of the year to correct the fault

[Agent Awesome]

How much of a deficit would I cop if my seaplane had, I dunno… 120+ parts

[Andetch]

4 hours ago, Agent Awesome said:

How much of a deficit would I cop if my seaplane had, I dunno… 120+ parts

High maintenance cost. Would be offset if it carries enough passengers or performs very well.

[Box of Stardust]

Test Pilot Review: @Overlonder's LJ-80 Family

Looks nondescript and conventional enough...

Figures as Tested (LJ-80-100 / LJ-81 / LJ-80SR, 72 passengers max):

• Price: 62,458,000
• Fuel: 1200 kallons
• Cruising speed: measured at 219.8m/s
• Cruising altitude: 5000m
• Fuel burn rate: measured at 0.15kal/s
• Range:  2,000km (as calculated)

Figures as Tested (LJ-80-100ER / LJ-81-ER / LJ-80, 72 passengers max):

• Price: 68,508,000
• Fuel: 2200kallons
• Cruising speed: measured at 202m/s
• Cruising altitude: 5000m
• Fuel burn rate: measured at 0.22kal/s
• Range:  2,020km

Review Notes:

Lorings Aerospace has designed a nondescript, conventional, and unassuming aircraft that meets the minimal passenger requirement for medium regional jets, but, due to the nature of Lotus engines, does not meet the minimum speed requirement. Therefore, to be a good contender, the LJ-80s should display stellar performance in all other aspects to be worth overlooking its low speed.

TCA has added an additional step in its testing process, consisting of a very quick pre-rollout statistical analysis. Initial statistical analysis showed a center of lift far behind the center of mass, so we expected poor pitch authority in its flight characteristics. This was already not a good sign.

In addition, aircraft designations were fairly confusing, with the initial briefing naming the aircraft under a long-form name, then a short-form name. Then once we received the prototypes, they were then referred to under a third different short-form designation, and we had to refer between documentation of parts to figure out which was which, which fortunately was fairly quick. We will be referring to the aircraft by the short-form designation (LJ-81) from here on.

LJ-81, the base version of the aircraft, was very basic, but still included flaps on the wings. These, however, were not wired to any specific control in the cockpit, and were only actuated by the brakes. As well, the tail controls were mixed to receive all inputs. We suspect that this was intentional, as the ailerons on the main wings were not set to respond to pitch or yaw. Further inspection discovered that the engine thrust reversers were also not wired to any control. All of these flight control issues were rectified before flight by TCA engineers. However, we missed the fact that the main gear was allowed to steer, in addition to their inward cant.

The LJ-81-ER was similar, but included more flaps, as well as spoilers for increased deceleration ability. Additional range was supposedly achieved through the addition of a belly tank holding 1000kal of fuel. Also, an additional exit door was added at the rear of the aircraft.

In both aircraft, the rear fuel tank was left unused and empty of fuel. As for passenger comfort, given the similarities to TCA airliner designs, comfort has been rated as good, with cabins shielded from decent portions of noise and vibrations due to the engine mounting design.

Part counts of 40 and 49 put them around average for maintenance, with most of the cost going to flight control surfaces. Two engines are about average maintenance.

LJ-81 Flight Testing

Flight testing began with the base-model LJ-81. Wheels up was achieved at ~64m/s, with tailstrikes impossible by nature of the aicraft's flight characterstics. Takeoff length was decent.

Flight up to cruise altitude was uneventful. The aircraft flew stable with or without SAS. Roll control was noted to be good. More importantly, pitch authority was poor, as was initially hypothesized. Cruise altitude was attained fairly quickly, around 3 minutes.

The poor aerodynamic setup manifested greatly in the cruise testing, requiring 30-40% of pitch-up trim setting, similar to the M38 tested by TCA previously. And much like the M38, we're not sure where the extra 1000km+ advertised range came from, with only a 2000km range as tested under the KEA range calculation equation, unless, of course, the advertised range was based off of a completely fueled aircraft using the tail tank. The highly efficient Lotus engines were only able to push the aircraft to a maintainable cruise speed of 219.8m/s; not even 220m/s unless in a shallow dive. The aircraft was otherwise stable and fairly easy to trim.

Engine failure testing came next. The LJ-81 performed well with a single engine failure, remaining very stable and easy to control, even without SAS turned on.

Full loss of power, however, did not fare well. The plane was unable to maintain level pitch for glide speed due to a severe natural pitch-down tendency. Pitch was maxed out and bled speed extremely quickly in doing so. A level attitude was unable to be maintained under 80m/s.

Under maneuverability tests, it was formally declared that the pitch authority was adequate at best for normal operations at speed, and sluggish for all other cases. The LJ-81 was extremely sluggish at mid-speeds, with its pitch-down tendencies showing more. At low speed, it loses a lot of altitude on turns and was very hard to maneuver due to exacerbated poor pitch control.

Landing was difficult due to this fact, and its wing-mounted landing gear meant that a safe landing could only be performed at higher speeds, where vertical velocity could be kept at a minimum. This was discovered after attempting to land under 80m/s, which caused too much stress on the wings trying to absorb the vertical velocity upon contact with the runway, and the prototype proceeded to break up further after this damage.

Water landing tests showed that the cockpit separates from the fuselage. The body remains intact, but the engines are lost. This is the best case scenario after maintaining maximum pitch-up input and attempting to impact the water at the lowest feasible horizontal velocity.

LJ-81-ER Flight Testing

More weight, very slightly more lift, no extra power with already no extra power to spare from the LJ-81.

It tended to steer randomly during the takeoff run. Attributed to inward cant of main gear combined with unlocked steering. Wheels-up was achieved at ~80m/s, on the edge of allowed takeoff speed. Takeoff length was acceptably moderate.

Cruise altitude was reached under 3 minutes, partially due to its relatively low cruising altitude of 5,000m. No significant differences from base LJ-81.

Again, pitch control was lacking. Trim for maintaining cruise conditions required 55-65% of available pitch authority. Cruising speed was measured at an abysmally low speed of 202m/s, and the engine efficiency suffered immensely. Range, based on optimistic (read: not TCA conservative) standards of maximum as-loaded fuel load was, from the LJ-81 base, improved by a mere 20km.

Engine failure characteristics were the same as the base LJ-81, except that full power loss is even worse due to potentially increased forward mass depending on fuel load, which intensifies the poor pitch ability of the LJ-81-ER. Level pitch can only be achieved with great difficulty at moderate velocity. Unpowered glide capability should be considered as 'minimal' to 'none'. Essentially, the aircraft must always be under power; otherwise, the aircraft is rendered unable to maintain positive or zero pitch at speeds under 130m/s.

Landing performance was also worse, both for standard ground landing and emergency water landing. Due to poor low-speed directional control, lining up to a runway had to be done a fair distance away. More flaps might have helped, but they weren't wired to a separate control. Spoilers and engine thrust reversers, as of this aircraft's state, were unneeded, as it needed velocity, not bleed it.

 

A fire emergency in Twin Crown Aerospace's prototype storage hangars prohibited us from testing the cargo variant, which was lost with all remaining LJ-81 aircraft prototypes, in addition to various TCA property. Source discovered to be poor welding practices around an A-50X prototype, which started a fire that spread to the nearby Military Applications Division hangars storing various explosive munitions. Recovery efforts around the facility and reconditioning will slow progress in processing further outsourced aircraft testing.

The Verdict:

Lorings Aerospace's LJ-81 family is designed almost how Twin Crown Aerospace would have designed a medium regional jet with conventional cabins, with a design that appears very conventional and unassuming. However, the devil is in the details, and the LJ-81s proved to be poor performers in vital flight characteristic categories, mostly stemming from poor pitch characteristics. The rear tanks were left unused, and the aircraft may have performed better were they filled and set to lowest drain priority to bring CoM back closer. Or simply adjusted angle of horizontal stablizer to push CoL up. Likely both would have been required, short of a full airframe reconsideration.

Beyond these flaws found in testing, the aircraft as designed have low airspeeds, and they both come in with fairly steep entry prices. It would be difficult for an aircraft to outshine not meeting minimum design requirements in the first place even with a decent design, and this aircraft firmly does not have what it takes.

No orders by KEA firmly recommended. Design remedies suggested, though doubt has been cast over their eventual effects.

Edited June 3, 2018 by Box of Stardust

[Agent Awesome]

@Andetch

it flies just as well as the KB 90 and carries 72 passengers 

[CrazyJebGuy]

15 hours ago, neistridlar said:

Uhm, is that how the rules go? They just say big planes right? I mean it sounds reasonable of course, though I have not been following that rule since it was unclear. @CrazyJebGuy Clarification needed.

This thread is going a bit quickly for my tastes, couple days ago i was thinking page 31 was really new.

The rules say medium and large planes need two pilots, so I would interpret as anything medium regional jet or higher. Remember, that rule was made back when 200 was considered a behemoth. See what's considered a behemoth soon, I've just learned how to use autostruts!

[Box of Stardust]

5 minutes ago, CrazyJebGuy said:

This thread is going a bit quickly for my tastes, couple days ago i was thinking page 31 was really new.

The rules say medium and large planes need two pilots, so I would interpret as anything medium regional jet or higher. Remember, that rule was made back when 200 was considered a behemoth. See what's considered a behemoth soon, I've just learned how to use autostruts!

Editor Extensions Redux allows you to toggle all autostruts on a vessel at once, as well as do/toggle all Rigid Attach, which might be far less phantom-force-y. But you'll need to double up in the worst of cases, or even place real struts between more load-bearing parts that autostruts won't strut between. 

Also, rigid attaching and maybe auto-strutting wings can be bad. Be careful about that. 

[CrazyJebGuy]

Just now, Box of Stardust said:

Editor Extensions Redux allows you to toggle all autostruts on a vessel at once, as well as do/toggle all Rigid Attach, which might be far less phantom-force-y. But you'll need to double up in the worst of cases, or even place real struts between more load-bearing parts that autostruts won't strut between. 

Also, rigid attaching and maybe auto-strutting wings can be bad. Be careful about that. 

By the way after you advised KEA to not buy the Slinky 152, and then suggested some other Neist planes, can I suggest my own plane? The GK-6 Konig? It is like the slinky in price, (slightly worse) but it is also not chronically under-powered.

[Box of Stardust]

3 minutes ago, CrazyJebGuy said:

By the way after you advised KEA to not buy the Slinky 152, and then suggested some other Neist planes, can I suggest my own plane? The GK-6 Konig? It is like the slinky in price, (slightly worse) but it is also not chronically under-powered.

That wasn't me (though I would've probably reached the same verdict).

There should be a publicized, non-editing/view-only link for the records/aircraft list, by the way. Would make it easier for everyone, guests especially, to know the state of various aircraft and past reviews.

Edited June 3, 2018 by Box of Stardust

[Eivuii]

Wait, @Box of Stardust, my company Kerlin Industries focuses on turboprops. What are your recommendations for a turboprop seaplane?

Thanks!

[Andetch]

39 minutes ago, Agent Awesome said:

@Andetch

it flies just as well as the KB 90 and carries 72 passengers 

I'm not a judge - just a thread enthusiast. There is really only one way to tell - get it flying as best as you can, test it for all it's potential flaws and try and sort them out, then submit it and see. 

[CrazyJebGuy]

7 minutes ago, Andetch said:

I'm not a judge - just a thread enthusiast. There is really only one way to tell - get it flying as best as you can, test it for all it's potential flaws and try and sort them out, then submit it and see. 

I was accused once that my reviews promote my planes. And I will say, it's no coincidence that I review planes and reward the types of things my own planes do. But that's not because of biased judging, that's because as a submitter I consider what I would say if I were to review it, and my submissions are better for it.

The single best plane building tip I can offer, consider what the judge would say.

[Agent Awesome]

K

[Eivuii]

1 hour ago, CrazyJebGuy said:

I was accused once that my reviews promote my planes. And I will say, it's no coincidence that I review planes and reward the types of things my own planes do. But that's not because of biased judging, that's because as a submitter I consider what I would say if I were to review it, and my submissions are better for it.

The single best plane building tip I can offer, consider what the judge would say.

Quite inspirational, that tip. Thanks!

 

[neistridlar]

3 hours ago, Box of Stardust said:

There should be a publicized, non-editing/view-only link for the records/aircraft list, by the way. Would make it easier for everyone, guests especially, to know the state of various aircraft and past reviews.

We could do the same with the KEA judging sheet as I did with the KEA lifetime cost sheet. It would reqire all judges to have a Google account. That already seems to be the case though, and it is free to make one, so I suppose that should not be a problem. 

[hoioh]

3 hours ago, CrazyJebGuy said:

By the way after you advised KEA to not buy the Slinky 152, and then suggested some other Neist planes, can I suggest my own plane? The GK-6 Konig? It is like the slinky in price, (slightly worse) but it is also not chronically under-powered.

That was me, I'm not familliar with the GK-6 König, but I'll give it a go later.

Just started a new job and finally have the weekends off, at the cost of all weekdays and a training period that requires I get up before 7am to be there on time. So I might not be able to do as many reviews as I like. The training period is about 6 weeks (yes that's long and very rare in sales, but highly appreciated on my part). 

 

In regards to @neistridlar's idea to make the judging sheet viewable to all, I support this wholeheartedly. (I would recommend linking it in the OP, together with the lifetime costs sheet.) It allows for all to see the amounts bought. It would however require we put a very small note with every plane stating the reason for the purchase, or lack thereof. This way you could look around the sheet, find a desirable plane and see what could be improved, try for yourself, and come up with an even better design removing some shortcoming of the original. Without rote copy ofcourse, which we would consider plagiurism obviously.

Anyway, just my 2 cents, would like to hear some other opinions

Edited June 3, 2018 by hoioh

[Box of Stardust]

4 hours ago, hoioh said:

In regards to @neistridlar's idea to make the judging sheet viewable to all, I support this wholeheartedly. (I would recommend linking it in the OP, together with the lifetime costs sheet.) It allows for all to see the amounts bought. It would however require we put a very small note with every plane stating the reason for the purchase, or lack thereof. This way you could look around the sheet, find a desirable plane and see what could be improved, try for yourself, and come up with an even better design removing some shortcoming of the original. Without rote copy ofcourse, which we would consider plagiurism obviously.

Anyway, just my 2 cents, would like to hear some other opinions

Well, first off, this one was me mentioning the idea first.

Next would be a need for refinement of the 'ordered/leased' number and the factors determining such, because we currently have no formal declaration of determining procurement amount. It's just this odd subjective number that goes per-reviewer. Frankly, I think the 'amount bought' number is... dumb, as of right now. Which is why I simply 'approve' or 'unapprove' planes.

I'd rather scores be kept to the measurable numbers, which I think could use some further refinement for taking into account all of an aircraft's design features, not just flat operation costs, but also comfort, safety, and flight characteristics. 

[neistridlar]

31 minutes ago, Box of Stardust said:

Well, first off, this one was me mentioning the idea first.

Next would be a need for refinement of the 'ordered/leased' number and the factors determining such, because we currently have no formal declaration of determining procurement amount. It's just this odd subjective number that goes per-reviewer. Frankly, I think the 'amount bought' number is... dumb, as of right now. Which is why I simply 'approve' or 'unapprove' planes.

I'd rather scores be kept to the measurable numbers, which I think could use some further refinement for taking into account all of an aircraft's design features, not just flat operation costs, but also comfort, safety, and flight characteristics. 

I think I may have at some point suggested similar stuff before you, and CrazyJebGuy even posted a copy once. This time around though, you were clearly first, seeing as I responded to your comment . On the better organizing of stuff and scoring. You are welcome to come up with concrete suggestions of how to accomplish it. The subjective numbers bought etc. is definitively not very good, I will gladly agree on that, but for now it is the best we have, so until a better way comes along I think it would be best if all of us stick to it.

There are other problems with the rules as well, like the mk1 passenger cabin being ridiculously cheap per seat compared to everything else. Also there is the issue of having a supersonic plane with 168 passenger capacity cruising at 14km, is classified as a jumbo, and expected to have 4000km range, while the same plane cruising at 16km, breaks the rules for supersonic, and thus it is classified as a supersonic, and only expected to have 1500km range.... I do think it is a little late doing drastic changes to the rules of this challenge now, being many months in to it. If we can make up a better, more consistent, balanced and objective set of rules for the challenge though, It might be time to close this one down, and do a reboot, with fresh sheets and new rules. Of course every one that has submitted to this challenge should have their reviews finished, so no one is left out.

[hoioh]

40 minutes ago, Box of Stardust said:

Well, first off, this one was me mentioning the idea first.

Next would be a need for refinement of the 'ordered/leased' number and the factors determining such, because we currently have no formal declaration of determining procurement amount. It's just this odd subjective number that goes per-reviewer. Frankly, I think the 'amount bought' number is... dumb, as of right now. Which is why I simply 'approve' or 'unapprove' planes.

I'd rather scores be kept to the measurable numbers, which I think could use some further refinement for taking into account all of an aircraft's design features, not just flat operation costs, but also comfort, safety, and flight characteristics. 

I didn't want to claim anything, that's why I agree, but yeah, Neist mentioned it just now so that's what I simply responded to. Frankly I don't really care who came up with it, it's a good idea so we should pursue it.

As to the effective scoring, I was on the same path earlier with the design of a bunch of bronze, silver and gold medals to support the challenge: 

I think this would be a decent reward for planes that are respectively:

1. Bronze: good enough (AKA it flies well enough to consider a purchase)
2. Silver: Really good and sort of efficient (AKA it flies really well and is averagely efficient)
3. Gold: Really good and really efficient (AKA it flies really well AND is in the top 16% most efficient and cost effective)

This would make the numbers less arbitrary, but we would also have to start setting up a testing procedure and scoring for each test, which would be more official and more objective, but maybe also less fun for the reviewers?

We could use the judging sheet to start to make a setup to judge (please extend this list):

Roll control
Yaw control
Pitch control

Attitude at cruise
Stability at cruise
Meets cruise requirements

KPPM
Seat price
LIP10 (a metric @neistridlar and myself came up with a few months ago that scores the lifetime cost per seat mile based on a whole range of plane characteristics, not just fuel efficieny)

Integrated safety features
Behaviour with engine failure
Take-off and landing safety

Please add

Using numbers 1 - 5 for each respective criterium (1 for really bad, 5 for excellent)

[neistridlar]

14 minutes ago, hoioh said:

Roll control
Yaw control
Pitch control

Attitude at cruise
Stability at cruise
Meets cruise requirements

KPPM
 Seat price
LIP10 (a metric @neistridlar and myself came up with a few months ago that scores the lifetime cost per seat mile based on a whole range of plane characteristics, not just fuel efficieny)

Integrated safety features
Behaviour with engine failure
Take-off and landing safety

Please add

I like this. Roll control could be measured in deg/s at cruise, and approach speed. Pitch could be measured in Gs at the same speed. Yaw side slip angle at the same speeds? Not entirely sure how relevant the yaw control is, since it really is just to help keep the aircraft point into the wind. I think these parameters should just be a Go/Nogo kind of score, if it is within acceptable parameters it is good, if not the aircraft is deemed not fit for service.

Other hard metrics that I collect for my reviews are:

Takeoff and landing speed

Takeoff and landing distance (the biggest one would be the limiting factor as to how big an airport it needs)

Parts per seat might also be interesting.

For Behavior with engine failure, scoring could be something like this:

not possible to land without engines: not fit for service

possible to make emergency landing (no fatalities): fit for service

possible to continue flight to nearest airport: fit for transoceanic flights.

Also up for consideration would be engine failure during takeoff/landing, is it fatal or not.

 

edit: For silver score, I am thinking above average is a nice limit.

Edited June 3, 2018 by neistridlar

[SLAMOVNIK989]

Sounds good for me.
I like that idea.

[hoioh]

4 minutes ago, neistridlar said:

I like this. Roll control could be measured in deg/s at cruise, and approach speed. Pitch could be measured in Gs at the same speed. Yaw side slip angle at the same speeds? Not entirely sure how relevant the yaw control is, since it really is just to help keep the aircraft point into the wind. I think these parameters should just be a Go/Nogo kind of score, if it is within acceptable parameters it is good, if not the aircraft is deemed not fit for service.

Other hard metrics that I collect for my reviews are:

Takeoff and landing speed

Takeoff and landing distance (the biggest one would be the limiting factor as to how big an airport it needs)

Parts per seat might also be interesting.

For Behavior with engine failure, scoring could be something like this:

not possible to land without engines: not fit for service

possible to make emergency landing (no fatalities): fit for service

possible to continue flight to nearest airport: fit for transoceanic flights.

Also up for consideration would be engine failure during takeoff/landing, is it fatal or not.

 

edit: For silver score, I am thinking above average is a nice limit.

I was thinking in ratings 1through 5 for each item, so if yaw control is too little, the plane tends to sideslip and if it's too much it's posible to get into a flat spin easily, that would be a 1 or a 2. If these aren't concerningly easy it would be a 3 or a 4 and if it's completely impossible that would be a 5.

For pitch control a 1 or 2 would be either inadequate, or able to flip the plane and travel backwards, a 3 if it's strong, but doesn't flatten the passengers if used appropriately, a 4 if it's adequate and simply can't flatten the passengers and 5 if it's just so smooth you can't belive it.

For roll control a 1 or 2 would be either way too strong, or way too little, a 3 would be adequate, but twitchy, a 4 would be a little too strong or weak, but close and 5 would be just excellent roll control

Those engine failure ratings could be numbered 1 through 4, where 4 is obviously better and a 5 would be: I didn't notice we had an engine failure actualy?

Take-off and landing speed are good additions, maybe climb speed? or time to reach cruise parameters?

 

By assigning numbered ratings you leave some subjective measure (maintaining judge fun level), but you will smooth out discrepancies with the averages across the field

 

 

[hoioh]

31 minutes ago, neistridlar said:

edit: For silver score, I am thinking above average is a nice limit.

Basically no red or yellow bars at the bottom of the lifetime cost sheet, but no greens either

[neistridlar]

5 minutes ago, hoioh said:

Basically no red or yellow bars at the bottom of the lifetime cost sheet, but no greens either

I was thinking more a holistic average of everything. since it is possible to both have green and red ones on the same plane. And then you have planes like the slinky 152, which is all greens, but otherwise entirely terrible for most practical purposes. There will have to be some clever math involved or some subjective judgement, or maybe some simple rules. Like no reds, or otherwise unfit for service, and otherwise, at least half of scores above some arbitrary average limit.

I like the 1-5 type scoring idea. There needs to be some guidelines for the limits still, like how many G's does it take to squish a kerbal? I am suggesting 10Gs as the upper limit, and 5G at cruise speed to be the minimum for a 3-4 ish score. Now the upper limit only needs to be easy to not exceed, if the plane can exceed it if you do so intentionally I don't think that is to bad, unless you want a 5.

I realized we have not touched on passenger comfort yet. I think this is probably the most subjective of all, but maybe it is possible to make up some kind of scoring system for that as well.

[Box of Stardust]

1 hour ago, neistridlar said:

I think I may have at some point suggested similar stuff before you, and CrazyJebGuy even posted a copy once. This time around though, you were clearly first, seeing as I responded to your comment . On the better organizing of stuff and scoring. You are welcome to come up with concrete suggestions of how to accomplish it. The subjective numbers bought etc. is definitively not very good, I will gladly agree on that, but for now it is the best we have, so until a better way comes along I think it would be best if all of us stick to it.

There are other problems with the rules as well, like the mk1 passenger cabin being ridiculously cheap per seat compared to everything else. Also there is the issue of having a supersonic plane with 168 passenger capacity cruising at 14km, is classified as a jumbo, and expected to have 4000km range, while the same plane cruising at 16km, breaks the rules for supersonic, and thus it is classified as a supersonic, and only expected to have 1500km range.... I do think it is a little late doing drastic changes to the rules of this challenge now, being many months in to it. If we can make up a better, more consistent, balanced and objective set of rules for the challenge though, It might be time to close this one down, and do a reboot, with fresh sheets and new rules. Of course every one that has submitted to this challenge should have their reviews finished, so no one is left out.

Well, I'm not that great at coming up with formal math equations, but I can outline some points in the system we can add. 

For starters, we can consider the Mk1 cabin to be an 'economy'-level cabin, with a base comfort value. The Mk2 is wider, so more 'bussiness-class'. For the Size 2 and Mk3 cabins, I guess it gets the same treatment, but I think the Size 2 should get a slightly higher than base value due to its fairly high price. Maybe even give it the same value as a Mk2 cabin, depending how the price scales.

Then we can come up with modifiers for engine placement-related comfort, which will still have a factor of subjectiveness, but I think all the judges have a generally similar idea of how we rate this.

 

For maintenance, engine count obviously. We may need a modifier based on TweakScale re-sized parts (resized engines only?). A lot of aircraft here have their part count numbers increased by wing segments, which I always say 'maintenance will consist of checking welds between parts'; not exactly high maintenance despite increased part count.

 

This is all on top of what @hoioh said. Of course, exact mathematical forumlas to be determined. 

 

I think the outlined rules in this challenge are fine, though I've personally always disagreed at some level that a Mk2 cabin only holds 8 if a Size 1 cabin also holds 8. But again, I've self-justified that by considering Mk2 cabins as more luxurious. We just need to fine-tune how we interpret the results of testing. 

Edited June 3, 2018 by Box of Stardust