The Efficient Airplane Challenge

[ralanboyle]

1 minute ago, camacju said:

This is what you said. There wasn't any specification that it needed to be a command pod, just not a command chair. Airlock is not a command chair

I am aware of the rules I made. You found a loophole an exploited it. I know some challenge moderators want players to find loopholes. I am not looking for loopholes, I’m looking for efficiency. I am not upset with you or anyone, I’m just refining the language to keep everyone within the spirit of the challenge. 

[camacju]

Will my earlier 2.1 liquid fuel run still count then? It used a Mk1 lander can

[ralanboyle]

1 minute ago, camacju said:

Will my earlier 2.1 liquid fuel run still count then? It used a Mk1 lander can

Yes. Lander cans are fine. 

[Klapaucius]

Takeoff weight:  12,436

Fuel Used:  17

.00136.  Not bad for a plane I built ages ago that was not specifically for this challenge. I did fly pretty slowly.  It will do around 600 but will burn up if you try that for very long.

https://kerbalx.com/Klapaucius/Gertrude

 

[Klapaucius]

Hmm.  It would be interesting to see how this plays out on a per passenger basis. This plane is basically a flying billboard. It used 536 units of fuel getting to the Island Airfield.  The takeoff weight was 260,929.   That makes .002054198, which is not bad, all things considered.  It only had two crew but will hold 300. I did break off an engine while landing.

https://kerbalx.com/Klapaucius/Gormenghast-300-Person-Luxo-Liner

 

 

 

 

 

 

Edited May 14, 2021 by Klapaucius

[Klapaucius]

Got .001129 with this one.  It is  variant of my Bugs plane.  The original has a command chair which is not allowed here.  I could probably do a lot better with a different tail.

https://kerbalx.com/Klapaucius/Bugs

Takeoff weight 15937

Fuel: 18

 

 

 

 

 

 

Edited May 15, 2021 by Klapaucius
deleted some sentences that made no sense because I had changed aircraft entry.

[OHara]

21 hours ago, ralanboyle said:

Proving that bigger is better

I noticed F-icient-4, so I optimized my single engine propeller plane and cut the fuel in half.  Now I think maybe turboprops are not, in fact, very well balanced with jets.  I needed to manage the engine very closely to get good fuel efficiency -- just like a real variable-probe plane. 

I'll withhold single engine propeller v2 (which is just less-fun variant of v1) from the challenge (but leave it on KerbalX) until we see other turboprops.

[Edit: Well, if I mention it in the challenge thread, I've effectively entered it, so here it is.]

The turboprop efficiency depends on the lift/drag of the blades, so we want to keep them well sub-sonic to keep the drag low.  A slower-rotating prop, with more blades, gives the same thrust as before with less power wasted in drag of the blades.

The fuel burned by the turboprop is proportional to the RPM times the torque produced by the engine, even if the produced torque is more than needed to maintain the setpoint RPM -- that is, the RPM governor acts like a brake that wastes power whenever the engine could exceed the set RPM.  So I managed the throttle through the flight to supply just enough torque to stay near 100rpm, while also watching the pitch of the prop to keep the angle-of-attack between 7° and 10°. 

Imgur album here.   0.6 units of fuel to get 3019kg to the island, 0.000'20 units per kg.

Edited May 14, 2021 by OHara

[ColdJ]

Hi. I know I will never get top of the leaderboard but maybe just get on the board.

https://kerbalx.com/ColdJ/Pigs-Might-Fly

1.390 ton and 4 units of fuel.

Spoiler

Also did a slight adaption of my adaption of @swjr-swis SWIS-glider 2b that can throw me up to 4000 m and then glides empty the rest of the way.

4.603 tons and 12 units of fuel.

Spoiler

 

[ralanboyle]

Welcome to the party @ColdJ. I've added you to the leaderboards. 

[ralanboyle]

Alright @OHara, I'm not great at the fine points of props in KSP so I read your explanation and ran with it. I scaled it up and came up with this... 2 units of fuel divided by 11,498 is 0.000174 and yeah... I made new leaderboards... 

 

[Pds314]

Hmm... I notice that in the rules it doesn't mention anything about the vehicle actually being an aeroplane?

Because I think a 10000 tonne ship would work pretty well for Challenge #2. Especially with a turboprop for propulsion that's set up to be more appropriate for ship speeds. Or possibly blade-tip Junos since the BG turboprops are VERY fuel-hungry. That being said ground handling without discarding parts would be... eugh...

 

Edited May 16, 2021 by Pds314

[ColdJ]

Well if we can be that flexible. I can have 1 Kerbal in the capsule and another outside pushing the capsule all the way to the island.

[Pds314]

1 hour ago, ColdJ said:

Well if we can be that flexible. I can have 1 Kerbal in the capsule and another outside pushing the capsule all the way to the island.

Hmm true. I guess it should be at least an aircraft.

Managed to almost get to the island with 74 accessible LF in a 95-tonne blade-tip driven chopper, but ran out and crashed on the runway at the last second. Might try making it consume a bit less fuel since that would have been second on LB and I hope that method is good enough to get first. Alternatively maybe just dumping 60 tonnes of ballast on there could work, but I would be a bit concerned about whether that would fly.

Edited May 16, 2021 by Pds314

[ColdJ]

1 hour ago, Pds314 said:

Hmm true. I guess it should be at least an aircraft.

Managed to almost get to the island with 74 accessible LF in a 95-tonne blade-tip driven chopper, but ran out and crashed on the runway at the last second. Might try making it consume a bit less fuel since that would have been second on LB and I hope that method is good enough to get first. Alternatively maybe just dumping 60 tonnes of ballast on there could work, but I would be a bit concerned about whether that would fly.

Did your Kerbal survive? If it did it counts as long as you are somewhere on the island.

[ralanboyle]

@Pds314, Let's say the craft needs to me airborne. This could be defined as not touching the water.  

[ColdJ]

7 minutes ago, ralanboyle said:

@Pds314, Let's say the craft needs to me airborne. This could be defined as not touching the water.  

I was kidding, my Kerbals legs would get too tired.

Besides, if I was going to do it I would have told you after I reached the island having expended no fuel.

[Pds314]

21 hours ago, ColdJ said:

Did your Kerbal survive? If it did it counts as long as you are somewhere on the island.

No. =/ I used the Cupola which is really fragile.

[ColdJ]

1 hour ago, Pds314 said:

No. =/ I used the Cupola which is really fragile.