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Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Wed Nov 07, 2018 2:15 am
by Boxkite
GolfHotel wrote: I nominate @kanga for the thread drift of the week award! :D :D :D

Noooo......Let someone else have it for a change..

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Mon Dec 03, 2018 6:58 pm
by Flyin'Dutch'
Genghis the Engineer wrote:It would.

I'll see if I can dig out the latest research on the topic - it's certainly something I've seen discussed quite extensively at conferences, and was also being delivered on an MSc course I sat in on a few years ago, but I haven't seen any new papers for a couple of years.

G


@Genghis the Engineer

Any news on this?

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Tue Dec 04, 2018 11:40 am
by Genghis the Engineer
Good question.

When I looked into this, I found that whilst there are numerous course and conference notes advising broadly what I said earlier, I can't find anything in the peer reviewed scientific literature.

Which of-course, presents a challenge! I'm working on a paper on the impact of climate change on aircraft performance at regional airports at the moment (if you're interested, presently adding about 1.5m per year to average take-off distance for a turboprop, and about 4m for something about A320 size - that's climate change since 1955, not based on future models).

I've suggested to my co-authors that once we have finished that one, we have a go at latest science on sector length and climate emissions. I don't know their opinions yet, but if they don't want to play, I'll probably do it on my own, as it's worth doing.

G

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Tue Dec 04, 2018 11:46 am
by Flyin'Dutch'
Genghis the Engineer wrote: I'm working on a paper on the impact of climate change on aircraft performance at regional airports at the moment (if you're interested, presently adding about 1.5m per year to average take-off distance for a turboprop, and about 4m for something about A320 size - that's climate change since 1955, not based on future models).



I think that the airline beancounters have already worked that out and hence now want pilots to use the 'Flex' option when working out distances and engine settings for Take-offs.

Doing their thing for both the bottom line and climate.

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Tue Dec 04, 2018 11:55 am
by Genghis the Engineer
But they aren't necessarily publishing their results, and their bottom line covers more than *just* fuel.

But broadly - yes. Cheaper flights usually are better for the environment - because fuel burn is such a large part of both.

G

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Tue Dec 04, 2018 12:43 pm
by daysleeper
Flyin'Dutch' wrote:
Genghis the Engineer wrote: I'm working on a paper on the impact of climate change on aircraft performance at regional airports at the moment (if you're interested, presently adding about 1.5m per year to average take-off distance for a turboprop, and about 4m for something about A320 size - that's climate change since 1955, not based on future models).



I think that the airline beancounters have already worked that out and hence now want pilots to use the 'Flex' option when working out distances and engine settings for Take-offs.

Doing their thing for both the bottom line and climate.


weirdly reduced thrust take-offs + climb out often burn more fuel rather than less.

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Tue Dec 04, 2018 1:06 pm
by Genghis the Engineer
Indeed.

It's a truism, that different environmental emissions matter differently to different people. If live some distance from an airport then it's "obvious" that it's greenhouse gas emissions that matter; if you live underneath the flighpath, particularly the climbout or hold, it's noise. If you live very close to an airport, it's more likely the NOx and particulate emissions (including, of course those from ground equipment, buses, cars...). Unfortunately, at least in small tweaks, if you try to reduce one, you quite often find you've increased one of the others.

G

Re: The world's longest non-stop commercial flight in an A350 ....

PostPosted:Wed Dec 05, 2018 4:46 pm
by Genghis the Engineer
Aha, found it by accident whilst searching for something else. 1500-2000nm.

https://www.sciencedirect.com/science/a ... 2314001793

You can't see the detailed data from that - it's buried behind a paywall, but I got it through our university library.

kg of fuel per seat-nautical mile...

500-1000nm sectors, 0.049
1000-1500nm sectors, 0.041
1500-2000nm sectors, 0.039
2000-2500nm sectors, 0.042
2500-3000nm sectors, 0.047
3000-3500nm sectors, 0.048
3500-4000nm sectors, 0.048
4000-4500nm sectors, 0.050
4500-5000nm sectors, 0.051
5000-5500nm sectors, 0.052
5500-6000nm sectors, 0.059
6000-6500nm sectors, 0.067

So, per seat mile, between 2000 and 6500nm, roughly speaking you're pushing the carbon footprint up by about 37%. I'd guess the long A350 legs talked about here, nearer 100%, but I was always taught to extrapolate off the end of graphs at your peril!

G