Kerbal Express Airlines - Regional Jet Challenge

[Mjp1050]

Mundane Jet Place presents...

SideWinder I

 

Ladies and gentlekerbs, we at the Mundane Jet Place have designed for you a small, short-range turboprop, the SideWinder I. Designed for short hops of up to 800 km or more, the SideWinder comes with the latest in aeronautical advances: the Nose-Operated Propulsion Engine (N.O.P.E.). Unlike most other planes, the N.O.P.E. stylishly pulls the aircraft, instead of pushing it, allowing for greater control ability in the air. Topping out at 35 parts, the Sidewinder is simplistically designed and requires little maintenance, making it a reliable option for many airfields.

Technical Specifications:

• 1 pilot
• 24 passengers
• Takeoff Speed: 75 m/s
• Cruising Altitude: 9000 m
• Cruising Speed: 250 m/s
• Taildragger Landing Gear
• Length: 11.9 m; Width: 12.1 m; Height: 3.7 m
• Weight: 9.4 tons
• Cost: 17,380,000
• Parts: 35

https://kerbalx.com/Mjp1050/Sidewinder-I

[Rosvall]

On 7/3/2017 at 4:44 AM, keptin said:

Figures as tested:

• Price: $138,480,000
• Fuel: 1500/1500 kal
• Cruising speed: 256 m/s
• Cruising altitude: 7000m
• Fuel burn rate: 0.35 kal/s
• Mass: 45.9t

Review Notes: The thing that impressed us most with One More Booster Co's Kerb Ferry 72 is its hardiness. It's a sturdy bird, and it's airframe would undoubtedly last for decades of heavy service, but this structural integrity comes at a price: weight. At nearly 20 tons heavier than the comparable medium-haul aircraft, it burns extra fuel. It's four-engines give it additional redundancy during an emergency, but also contribute to higher maintenance costs.  It's extremely spacious, and with its rear cargo door, our inspection engineers guessed that it may be a converted cargo aircraft for passenger use. It certainly has the durability of a heavy cargo transport, but we're afraid that its high fuel burn rate would cut too deeply intro profits.

Our verdict: The One More Booster Co. Kerb Ferry 72 is a durable and rugged aircraft, perfect for cargo transport, but its high fuel burn rate makes it expensive for commercial passenger use.

Thanks for the review. We realize now that trying to build a commercial airplane out of spaceplane parts might have been a mistake. 

We have now invested in new parts designed for subsonic speeds that are much lighter! We can tease the release of a new model weighing in at under 18t! (are we allowed more than 1 entry?)

Edited July 4, 2017 by Rosvall

[Vinhero100]

This challenge looks great! only one question: how do you measure the cruising speed?

 

[sevenperforce]

11 minutes ago, Vinhero100 said:

This challenge looks great! only one question: how do you measure the cruising speed?

 

Cruising speed is the speed at which you obtain the highest range. Typically, this will be as high in the atmosphere as your craft can sustain level flight, since flying higher reduces drag and thus allows you to increase speed and decrease fuel consumption. I usually just go to full throttle and climb gently until I start having difficulty maintaining a steady ascent; at that point, I level out, set trim if applicable, and wait until my speed becomes constant. At this point, f/r*v (remaining fuel divided by fuel consumption rate times speed) gives me my remaining range in meters.

If your plane has a very high L/D ratio, then you may find a greater range is achieved by throttling down to 80% or so once you reach cruising altitude. But most of my planes find their optimal cruising speed at full throttle.

[PaperAviator]

Ahh I would love to enter in this challenge! Too bad I'm away on a trip and won't be back until 8/15... 

[sevenperforce]

KerbAir has announced its first entry into the small regional jet challenge, the Flying Fish. While some claim the Fish is ungainly, we at KerbAir prefer to think of it as uniquely elegant. In any case, whatever it may lack in perceived aesthetics it more than makes up for in performance and price.

At just shy of $9.8 million, it is by far the cheapest available aircraft in its class and the only regional jet with a sticker price under eight figures. This cost savings is achieved by the use of a streamlined profile and minimal part count. With only 18 separate components and a single engine, any mom-and-pop airline can perform all the required service in-house. A novel V-tail eliminates the added cost of a vertical stabilizer, with KerbAir's proprietary SAS technology allowing the V-tail to control both pitch and yaw. The canards used for the V-tail are obtained via a special arrangement with the TweakScale Corporation, giving KerbAir access to secondhand, undersized parts at reduced prices.

The Flying Fish obtains all its control with just four control surfaces, reducing maintenance associated with moving parts. The streamlined ailerons double as flaps for liftoff and landing. But don't let its economy-grade pricetag fool you! The Fish's powerful single engine propels it to its takeoff speed of 71 m/s in just over 500 meters, allowing it to take off and land on virtually any runway. Plus, the engine has a reversible thrust setting, permitting it to execute ultra-short landings as needed.

Its low mass and powerful engine allow it to climb to cruising speed and altitude in as little as five minutes after takeoff, critical for regional jets. With a cruising speed of a little over 250 m/s at just under 10 km, it is not the fastest jet in its class, but its fuel economy is impressive with a range of 1,720 km. What's more, this range is achieved with a total fuel load of just 400 units in a single tank, making each flight's fuel cost just $320K. With a full passenger load this equates to just $7.75 per passenger-km.

Pilots may notice that turns and landings can be challenging without a proper vertical stabilizer, so caution and careful control are recommended. Lowering the rear landing gear may help prevent excessive yaw on approach, at the cost of a little added drag.

If your airline has an aircraft body shop on site, setting the angle of wing incidence back to zero (easy, since the wings contain no fuel tanks) allows for simple conversion to a high-speed executive express jet. The express variant (the Flying Sculpin), has a higher takeoff speed but can easily surpass Mach 1 in cruise.

Craft file here. If you happen to reset the wing incidence to test the express variant, be sure to re-angle the front gear correctly to compensate.

Flaps (action group 1) are recommended for takeoffs below 80 m/s. Thrust reversal is set to action group 2 so that you can spin up the engine in forward-thrust mode before releasing the brakes, enabling shorter takeoffs.

[sdj64]

Here's an entry for the medium jet category.

Cobalt Air presents its first medium regional jet, the Juniper 80.  With an economical purchase price and excellent performance for a jet of this size, the Juniper 80 is an excellent solution for routes up to 2500 km in length.  The trijet configuration gives a TWR of almost 1 at sea level, and also allowing a higher cruising altitude.

Price: $37,380,000

Fully fueled weight: 36 tons

Part count: 46

Passenger capacity: 80

Pilots: 2

Takeoff speed: 70 m/s

Cruising speed and altitude: 275 m/s at 7500 m

Range: 2500 km

Fuel consumption: 0.258 units/s

Fuel capacity: 2400 units

 

Download link:  https://kerbalx.com/sdj64/Cobalt-Air---Juniper-80

 

There is a good deal of clipping in this jet, but the majority is just structural.  The main fuselage is made of mk2 cargo bays, and no fuel is stored inside, also, none of the cabins intersect each other.  I hope this is okay, given that the aircraft is fully stock.

Edited July 4, 2017 by sdj64
Added KerbalX link

[Vinhero100]

my plane so far has to take off at 90 m/s, which is frustrating because its so fast and can go up to 18 km

[sevenperforce]

30 minutes ago, Vinhero100 said:

my plane so far has to take off at 90 m/s, which is frustrating because its so fast and can go up to 18 km

Try lowering the rear gear so you're nose-up on takeoff, and adding flaps (or more flaps, or flaps with a greater deployment range).

If nothing else works, add an angle of incidence (this will lower your max speed, though).

[Guest]

3 hours ago, sdj64 said:

Here's an entry for the medium jet category.

Cobalt Air presents its first medium regional jet, the Juniper 80.  With an economical purchase price and excellent performance for a jet of this size, the Juniper 80 is an excellent solution for routes up to 2500 km in length.  The trijet configuration gives a TWR of almost 1 at sea level, and also allowing a higher cruising altitude.

Price: $37,380,000

Fully fueled weight: 36 tons

Part count: 46

Passenger capacity: 80

Pilots: 2

Takeoff speed: 70 m/s

Cruising speed and altitude: 275 m/s at 7500 m

Range: 2500 km

Fuel consumption: 0.258 units/s

Fuel capacity: 2400 units

 

There is a good deal of clipping in this jet, but the majority is just structural.  The main fuselage is made of mk2 cargo bays, and no fuel is stored inside, also, none of the cabins intersect each other.  I hope this is okay, given that the aircraft is fully stock.

I really like that!

[Vinhero100]

2 hours ago, sevenperforce said:

Try lowering the rear gear so you're nose-up on takeoff, and adding flaps (or more flaps, or flaps with a greater deployment range).

If nothing else works, add an angle of incidence (this will lower your max speed, though).

I set my flaps to 150% Authority, and They still don't work. I'm gonna try panthers on afterburner instead of whiplashes

Edit: Which worked! Takes off around 78 m/s... close!

Edited July 4, 2017 by Vinhero100

[keptin]

9 minutes ago, Vinhero100 said:

I set my flaps to 150% Authority, and They still don't work. I'm gonna try panthers on afterburner instead of whiplashes

Edit: Which worked! Takes off around 78 m/s... close!

Unless it's a very heavy craft, is your center of lift too far behind your center of mass?

[Vinhero100]

I got them close, but it is very heavy.. (38,201 Kilograms)

Edited July 4, 2017 by Vinhero100

[sevenperforce]

11 minutes ago, Vinhero100 said:

I set my flaps to 150% Authority, and They still don't work.

You have to be careful about flaps; depending on your airspeed, giving them too much authority can cause flow separation and a stall, which actually decreases your lift. Better to use longer flaps (i.e., longer chord length) than to stall them out.

Any chance we can get a screenshot? That might help with troubleshooting. One thing I mentioned before that's very useful: lifting your rear gear and lowering your forward gear allows you to already be pointed upward when you are taxiing toward takeoff, which gives the entire wing a high AoA and really kicks up the lift.

[Vinhero100]

5 minutes ago, sevenperforce said:

You have to be careful about flaps; depending on your airspeed, giving them too much authority can cause flow separation and a stall, which actually decreases your lift. Better to use longer flaps (i.e., longer chord length) than to stall them out.

Any chance we can get a screenshot? That might help with troubleshooting. One thing I mentioned before that's very useful: lifting your rear gear and lowering your forward gear allows you to already be pointed upward when you are taxiing toward takeoff, which gives the entire wing a high AoA and really kicks up the lift.

Edit: Just took off at 74 m/s!

Edited July 4, 2017 by Vinhero100

[sevenperforce]

18 minutes ago, Vinhero100 said:

Edit: Just took off at 74 m/s!

Use offset to move your rear gear up significantly.

[StupidAndy]

looks interesting, I'll have to try sometime, the submissions so far look great!

[Azimech]

Hey @keptin, I wanna talk to you about a possible entry.

This airplane is a modification of my stock Beechcraft Starship replica. It's not a "real" turboprop because I don't use part mods.

Not only that a "real" turboprop using one of my own engines wouldn't be able to enter because of the size & performance restrictions.

Instead, this airplane has two "spinny things" on the back. They only rotate, don't provide thrust. Instead they provide drag and vibrations but hey ... it looks like a propeller airplane.

A variant I'd propose would be one able to operate on rugged terrain with STOL features.

It's very easy to fly, full throttle with flaps is enough to get it airborne, no control input or SAS required. It also has a good range (1200km plus) and impossible to stall. If you like it, I'll provide the full detailed report.

 

 

Edited July 5, 2017 by Azimech

[Kryten 2X4B 523P]

Figured Id have a go at this.

 

Kryten's Engineering Konglomerate (KEK) would like to present:

 

The KEK Accolade Mk 2

Specification:

Passengers : 24

Price : 17,746,000

Take off Speed : 77 m/s with flaps (AG1)

Recommended cruising speed: 155 m/s

Recommended cruising altitude : 4500m

Theoretical range : 100/0.04 = 2500km

Max Altitude : approx 7000m

Max Speed : approx 170 m/s

Category: Turboprop

 

PR:

Ideal for short distance commuter or sightseeing flights, the KEK Accolade offers comfort, style and reliablility at an affordable price.

For the environmentally concerned traveller, noise and air pollution kept low through the use of the venerable J-20 engine which offers quiet running and excellent fuel efficiency.

Craft File : 

KEK Accolade

Edited July 5, 2017 by Kryten 2X4B 523P
revised entry

[keptin]

So many incredible entries, I'm getting behind in judging them all. I'm going to mark tomorrow as the submission deadline. You have 24 hours as of this post (9AM PST) to submit your designs!

12 hours ago, Azimech said:

Hey @keptin, I wanna talk to you about a possible entry.

 

 

Sweet starship! If you're submitting it as a turboprop, it must use Airplane Plus turboprop parts, otherwise it will be considered a jet, and must meet one of the jet category requirements. See contest rules for the variants that Kerbal Express Air is interested in. No other variants will affect judging score.

[Azimech]

17 minutes ago, keptin said:

So many incredible entries, I'm getting behind in judging them all. I'm going to mark tomorrow as the submission deadline. You have 24 hours as of this post (9AM PST) to submit your designs!

Sweet starship! If you're submitting it as a turboprop, it must use Airplane Plus turboprop parts, otherwise it will be considered a jet, and must meet one of the jet category requirements. See contest rules for the variants that Kerbal Express Air is interested in. No other variants will affect judging score.

Okay, I'll make an exception then.

Looking at the fact the design is very flexible with only minor adaptations (trim/fuel settings), can I also enter a jet variant?

Edited July 5, 2017 by Azimech

[Kryten 2X4B 523P]

23 minutes ago, keptin said:

So many incredible entries, I'm getting behind in judging them all. I'm going to mark tomorrow as the submission deadline. You have 24 hours as of this post (9AM PST) to submit your designs!

Sweet starship! If you're submitting it as a turboprop, it must use Airplane Plus turboprop parts, otherwise it will be considered a jet, and must meet one of the jet category requirements. See contest rules for the variants that Kerbal Express Air is interested in. No other variants will affect judging score.

In that case Id better withdraw mine - although in fairness it states the airplane plus bit is optional and doesnt indicate its mandatory for for the turboprop section (and yeah, know what a turboprop is, but as its not a stock part and listed as optional then I figured something juno powered would fit the category in terms of meeting the other criteria  - no worries, my bad)

[StupidAndy]

45 minutes ago, keptin said:

So many incredible entries, I'm getting behind in judging them all. I'm going to mark tomorrow as the submission deadline. You have 24 hours as of this post (9AM PST) to submit your designs!

so this challenge entry will end in 24 hours? so nobody can enter another plane ever? or will you reopen it after you get through them all?

[keptin]

40 minutes ago, Azimech said:

Okay, I'll make an exception then.

Looking at the fact the design is very flexible with only minor adaptations (trim/fuel settings), can I also enter a jet variant?

Players can submit one model per category. For the sake of this challenge, each category must be as separate "model".

31 minutes ago, Kryten 2X4B 523P said:

In that case Id better withdraw mine - although in fairness it states the airplane plus bit is optional and doesnt indicate its mandatory for for the turboprop section (and yeah, know what a turboprop is, but as its not a stock part and listed as optional then I figured something juno powered would fit the category in terms of meeting the other criteria  - no worries, my bad)

There are other considerations involving props, like prop clearance, that wouldn't be taken into account by using jets instead. You're welcome to modify yours and resubmit.

10 minutes ago, StupidAndy said:

so this challenge entry will end in 24 hours? so nobody can enter another plane ever? or will you reopen it after you get through them all?

Yep, that's the end! Get 'em in quick!

[StupidAndy]

Just now, keptin said:

Yep, that's the end! Get 'em in quick!

do you plan on after this to open it again? because it looks like a REALLY good challenge