The Aircraft Endurance Challenge

[Gman_builder]

1 hour ago, gridghost said:

Did a reinstall (and redownloaded the mods to be sure to have a clean install) and i still get crazy mileage from my planes. Did a retake on the Big bird with Wheesleys and got this... (Coming in for landing)

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See that there, Wheesleys are more efficient than panther's yet you get lower mileage in the wheesley powered version than the panther powered one.

[gridghost]

Just now, Gman_builder said:

See that there, Wheesleys are more efficient than panther's yet you get lower mileage in the wheesley powered version than the panther powered one.

Nope, i got 62 kkm with the Wheesleys and 51 with the Panthers...

[Gman_builder]

Just now, gridghost said:

Nope, i got 62 kkm with the Wheesleys and 51 with the Panthers...

Oh. Hmm. I am testing the panther powered version and so far it is still following the estimated flight duration that FAR predicted. I am 3,500 km in and it is exactly as predicted.

[MDZhB]

I was going to do this, but I realized I didn't have the patience to compete XD. I hardly ever fly any large distance, even though I have an airplane that I'm sure can circumnavigate pretty easily (I built it to do so, but I haven't done it)

[gridghost]

Nice  

I only got 9 hours (ish) out of the 12 predicted. And hopefully we get some answers as to why i get crazy mileage, still. And you might want to up the speed to 485 (I saw you had it on 450)

With the Wheesley one i calculated that i should have traveled 19 (ish) kkm given time and speed, but got 62(ish), which is 3.2 (approx) times longer then expected. It would be nice to know why.

Edited July 7, 2016 by gridghost

[Scientia1423]

I TL;DR the entire thing so how are you meant to know the distance you've travelled (is it F3?) and can I use VesselMover to move to a place (say, the Insular Airfield(you can't move in-flight)).

Edited July 7, 2016 by Scientia1423
10/10 -needs nothing more.

[Van Disaster]

2 hours ago, Gman_builder said:

I think FAR is calculating distance by determining the speed over ground, fuel usage per second, and how long that fuel will last at the current speed and altitude. But I don't think it can account for  the decreasing weight as you burn fuel. Which increases efficiency. So theoretically the estimated numbers should differ more and more from the actual numbers as the efficiency of the plane increase. I.E. A plane with a estimated flight distance of 1000 kilometers might go 1045 kilometers in reality, while a plane with a estimated flight distance of 100,000 kilometers will fly something like 125,000 kilometers. The same goes for flight time in hours.

FAR is doing a projection based on a bunch of things - pretty sure it *does* take fuel use changing drag into account somehow, hence I've still got a 117hr endurance prediction because my fuel use per sec is dropping rapidly, it's actually not changing very much anymore ( probably because of the large sample size this flight has provided already ). I dunno, I'll look up the source sometime. I'm still a bit curious about exactly what the stock game is using to calculate distances, but I'm sure that's been answered somewhere else...

@gridghostWhat's the result if you do just one orbit?

Edited July 7, 2016 by Van Disaster

[gridghost]

2 minutes ago, Van Disaster said:

 

@gridghostWhat's the result if you do just one orbit?

@Van Disaster I haven't tested that in this install yet. Will do and get back

[Gman_builder]

13 minutes ago, Van Disaster said:

FAR is doing a projection based on a bunch of things - pretty sure it *does* take fuel use changing drag into account somehow, hence I've still got a 117hr endurance prediction because my fuel use per sec is dropping rapidly, it's actually not changing very much anymore ( probably because of the large sample size this flight has provided already ). I dunno, I'll look up the source sometime. I'm still a bit curious about exactly what the stock game is using to calculate distances, but I'm sure that's been answered somewhere else...

@gridghostWhat's the result if you do just one orbit?

I think doing the calculation manually for your planes endurance would be more reliable than having the computer do it. As it is seemingly messed up in the case of @gridghost's plane. Anyway I just broke 6,000 kilometers in the big bird and I have burned 1/3 of my fuel. Seems like the prediction is extremely accurate in this case. It is definitely not going to make it to 51,000 kilometers.

Edited July 7, 2016 by Gman_builder

[Nefrums]

I'm trying a slightly different approach.

Looks like it should reach 70-80 Mm.

 

[gridghost]

1 hour ago, Gman_builder said:

I think doing the calculation manually for your planes endurance would be more reliable than having the computer do it. As it is seemingly messed up in the case of @gridghost's plane. Anyway I just broke 6,000 kilometers in the big bird and I have burned 1/3 of my fuel. Seems like the prediction is extremely accurate in this case. It is definitely not going to make it to 51,000 kilometers.

I would like to see an unedited sceenshot of the results of the trip later on...

1 hour ago, Van Disaster said:

 

@gridghostWhat's the result if you do just one orbit?

@Van Disaster Going Mach 4 @ 23000 km, i got 9.1 kkm

Spoiler

 

[Gman_builder]

41 minutes ago, gridghost said:

I would like to see an unedited sceenshot of the results of the trip later on...

@Van Disaster Going Mach 4 @ 23000 km, i got 9.1 kkm

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That's definitely the longest range almost hypersonic plane I've seen. What do you mean unedited screenshots? I've never edited a screenshot except for selective focus. Which I have only done twice.

[Van Disaster]

52 minutes ago, gridghost said:

I would like to see an unedited sceenshot of the results of the trip later on...

@Van Disaster Going Mach 4 @ 23000 km, i got 9.1 kkm

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*scratches head*. Kerbin is 600km radius, so about 3700 round at sea level. That is a very odd difference.

[Gman_builder]

1 hour ago, Van Disaster said:

*scratches head*. Kerbin is 600km radius, so about 3700 round at sea level. That is a very odd difference.

Well, the actual math says that the circumference of a sphere with a radius of 600 is 3770.

C = 2pi  x  600

1200pi

1200pi  =  3770 kilometers in diameter. Which makes no sense because you fly 5,800 kilometers when doing a circumnavigation.

Edited July 8, 2016 by Gman_builder

[Van Disaster]

Is it not sidereal distance rather than surface relative? ie an orbit, so KSC's movement is added if you just go round once and land. I guess gg's Kerbin might be rotating really fast...

Also, not doing maths involving pi to any great accuracy in my head

[Gman_builder]

5 hours ago, Van Disaster said:

Is it not sidereal distance rather than surface relative? ie an orbit, so KSC's movement is added if you just go round once and land. I guess gg's Kerbin might be rotating really fast...

Also, not doing maths involving pi to any great accuracy in my head

ya I don't expect you to. I used a calculator. Lets see here, Kerbin does a full rotation over a 6 hour period and it has a circumference of roughly 3770 kilometers.

3770km / 360 mins = roughly 175 m/s. (or 280 m/s i'm not really sure, I failed second semester math  )

So Kerbin really isn't rotating that fast. It is just really small. Making circumnavigations vary extremely in distance based on which way you fly and your speed. On that note, I completed my test flight of @gridghost's plane. The results were as expected.

It went 5 thousand kilometers over the original estimate. Which is forgivable. Not 31 thousand kilometers over.

[gridghost]

@Gman_builder Why are you using afterburner at low altitude? 

 

As to my rig and my install... seeing as i have a clean install with just FAR, Pilot assistant and BD Armory (not used here) and a constant 120 FPS i would rather think that it's not MY install that not up to snuff.

But yes, @Van Disaster i'm rather confused by the numbers myself... as you say, the numbers doesn't add... any circumnavigation eastwards should show up as approx 3.768 kkm (some variation of course but not much) plus rotation. In my case that would be 4,396 kkm given 1/6th rotation in 55 minutes. And going Mach 4 would affirm that. Going 200 m/s would take 5 hours and 14 minutes to get 3,768 kkm and the planet would have orbited 5/6th rotation giving 6.908 kkm.
Ah, well... I'll lower my FPS to 60 and see if my theory works.

[Van Disaster]

I can't imagine why it'd be affecting anything but maybe pull BDA out ( it's technically not 1.1 compatible anyway unless there's a fork I missed ).

Sitrep: look, almost down to half fuel!

Probably going to have to land today though, I will need full use of this PC soon.

[zolotiyeruki]

Can I copy and paste my final entry from the Circumnavigation challenge?  My craft flew for right around 8 hours, and got around Kerbin 12 times for a total ground distance of 47,000 km (12x around * 2*pi* 625km radius)*, and met all the other requirements. On the whole "higher/faster" thing, here's the deal:  at significant fractions of orbital velocity, your craft needs less lift in order to maintain altitude.  Less lift means less induced drag, which means higher speeds and/or lower fuel consumption.  By the time my craft was on its 12th circle and almost out of fuel, it was running at >1500m/s while only consuming about 0.05 LF/sec.

Of course, that was before reentry heating got a lot tougher in 1.0.5...

* if you add the rotation of Kerbin, that's another 1.33 * 625 * 2*pi = 5230km

Edited July 8, 2016 by zolotiyeruki

[Van Disaster]

If you're adding altitude to Kerbin's radius to get your actual distance travelled, then it's not ground distance Kerbin was 600km radius at sea level last time I checked.

[zolotiyeruki]

52 minutes ago, Van Disaster said:

If you're adding altitude to Kerbin's radius to get your actual distance travelled, then it's not ground distance Kerbin was 600km radius at sea level last time I checked.

Fine, fine.   12*600*2*pi = 45,216km (plus 8 hours of kerbin's rotation = 5000km)

Still probably shouldn't count, though, since it was done under 1.0.4 and back then, sustained atmospheric flight at 1600+m/s was possible.

[gridghost]

8 hours ago, Van Disaster said:

I can't imagine why it'd be affecting anything but maybe pull BDA out ( it's technically not 1.1 compatible anyway unless there's a fork I missed ).

 

I did another clean install, with only FAR, Dynamic deflection and Pilotassistant, locked the FSP @ 60 and still got 8 kkm on a circumnavigation that normaly would have netted me 5.424 kkm (390ms/s at 15.500 m) It's still better than the crazy mileage i got earlier... I think that it's somewhat linked to FPS and Physics-calculation being bound to 24 or 25 FPS and without any graphical mods i can't get the FPS lower than 60.

[Gman_builder]

8 hours ago, zolotiyeruki said:

Can I copy and paste my final entry from the Circumnavigation challenge?  My craft flew for right around 8 hours, and got around Kerbin 12 times for a total ground distance of 47,000 km (12x around * 2*pi* 625km radius)*, and met all the other requirements. On the whole "higher/faster" thing, here's the deal:  at significant fractions of orbital velocity, your craft needs less lift in order to maintain altitude.  Less lift means less induced drag, which means higher speeds and/or lower fuel consumption.  By the time my craft was on its 12th circle and almost out of fuel, it was running at >1500m/s while only consuming about 0.05 LF/sec.

Of course, that was before reentry heating got a lot tougher in 1.0.5...

* if you add the rotation of Kerbin, that's another 1.33 * 625 * 2*pi = 5230km

If It was made before 1.1.3 I will not count it. As physics were different back then.

1 hour ago, gridghost said:

I did another clean install, with only FAR, Dynamic deflection and Pilotassistant, locked the FSP @ 60 and still got 8 kkm on a circumnavigation that normaly would have netted me 5.424 kkm (390ms/s at 15.500 m) It's still better than the crazy mileage i got earlier... I think that it's somewhat linked to FPS and Physics-calculation being bound to 24 or 25 FPS and without any graphical mods i can't get the FPS lower than 60.

When I did the run in your 51kkm plane I was getting a near constant 60 FPS. It occasionally dropped to 50 or spiked to 70 but the results were consistent with all other flights ive done and the other flights that have been done for this challenge. I was using AB to burn off the remaining 50 units of fuel because I wanted to land in that river.

Edited July 8, 2016 by Gman_builder

[Baybrawler]

Are we allowed to use drop tanks? Also, is timewarp allowed to make the flight faster?

 

Thank you,

Baybrawler

Edited July 9, 2016 by Baybrawler

[Van Disaster]

Past 100,000km. Will be sleeping & landing when I wake up, so another 2-3 orbits probably. At current burn rate it could go another 60k km, let alone allowing for burning off mass ( still 32t of fuel or so onboard ).

@gridghosttry messing with the physics min frame slider or whatever that thing is called?

Edited July 9, 2016 by Van Disaster