GCC: Flying first class on a single domestic round trip can contribute more greenhouse gas emissions than a year of driv

GRA said:

Optimizing the hop lengths: long-range planes (designed for a range
of say 15 000 km) are not quite as fuel-efficient as shorter-range planes,
because they have to carry extra fuel, which makes less space for cargo
and passengers. It would be more energy-efficient to fly shorter hops in
shorter-range planes. The sweet spot is when the hops are about 5000 km
long, so typical long-distance journeys would have one or two refuelling
stops (Green, 2006). Multi-stage long-distance flying might be about 15%
more fuel-efficient; but of course it would introduce other costs.

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https://www.withouthotair.com/cC/page_278.shtml

The technical chapter on flight of the above, Chapter C, runs from page 269-282.

The reference is to this:

Green, J. E. (2006).
Civil aviation and the environment – the next frontier for the aerodynamicist. Aeronautical Journal, 110(1110):469–486.

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Unfortunately I haven't been able to find a version that isn't behind a paywall.

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A 777-200, state of the art in 2000, has an optimum hop distance of about 5,600 km. That's the distance where the fuel use per passenger mile is minimum. For example:


A 787 has an optimum hop distance of about 7,300 km

Calling trips beyond the optimum hop distance inefficient is making several assumptions that are usually not realistic.

There likely isn't an airport right under your direct flight path at the ideal distance to stop on, so adding the stop adds distance. This also makes the legs different lengths. This can be complex, as there can be many choices, and the aircraft might be different on different legs.

A 777-200 flight to 3000 nm compared with two 1500 nm legs, the two legs are not cheaper. (look at above graph)

Learn something new everyday.

I'm skeptical though that even the CC faithful would forsake flying and put up with a month long sailing adventure just to go one way. Think of the wealthy, entertainers, sports figures, business leaders, government officials carrying out crucial affairs of state... all those people who are more important than us, their time is just too valuable. Fortunately Qantas is doing something to ease their burdens:

https://www-cnn-com.cdn.ampproject.org/v/s/www.cnn.com/travel/amp/worlds-longest-flight-london-sydney-10-things/index.html?amp_js_v=a2&amp_gsa=1&usqp=mq331AQCKAE%3D#referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.cnn.com%2Ftravel%2Farticle%2Fworlds-longest-flight-london-sydney-10-things%2Findex.html

Given the available, more comfortable and much faster options, few if any are going to accept transoceanic crossings by sail, which is why, given the likely limited supply, sustainable biofuels' most critical niche will be (and already is in a few places) long-range aviation. Barring an emergency, I'm not planning to fly anywhere in a jet again until I can do so on 100% biofuel. For those interested, see the "Biofuels" topic for posts describing developments along that line, or go direct to my source for most of those stories, at Green Car Congress: https://www.greencarcongress.com/aviation/

or the numerous "Bio-" prefixed categories found on the right side of the page here: https://www.greencarcongress.com/

I figure H2/fuel cells will work for regional/commute trips on propeller a/c when trains aren't justified, and batteries MAY progress to the point where they can be used for puddle jumping and similar very short-haul commercial use.

Mr Gra, how would you feel about a $500 surcharge per passenger on international flights in and out of the US?

LTLFTcomposite said:

I'm skeptical though that even the CC faithful would forsake flying and put up with a month long sailing adventure just to go one way.

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Possible and likely are two different things. Saying it is not possible is incorrect. I mostly agree, near term, that few will take the sailing adventure, perhaps as many as double the several thousands that do so now. Ten's of millions fly across the Atlantic now. The far future? Who knows.

Surcharge per passenger... I'd rather see a carbon tax, and it is too early for a carbon tax. Subsidies for low carbon electric production (solar, wind, hydro, nuclear and geothermal) are lower cost at this point in time.

LTLFTcomposite said:

Mr Gra, how would you feel about a $500 surcharge per passenger on international flights in and out of the US?

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I'd assume that applies to Hawaii too... Guam? Alaska? Why would JFK to LAX be "better" to fly than JFK to YYZ?

There would be a lot more flights to border towns in Mexico and Canada. Basically the average person wouldn't ever leave the country and those that already do, will continue to do so because $500 is chump change on a $20k ticket. The non-competitive US airlines will just stop flying. Lots of money comes from those transiting through the US. As it is now, I know lots of people who fly through Toronto or Vancouver instead of the US to get to the islands for political reasons. For those that don't care about the politics, a $1000 surcharge on the ticket will make it pointless. Fly LHR->EWR->POS is usually $2k. LHR->YYZ->POS is usually about $2.25k. Add in $500 for each international flight and now it is $3k for the privilege of being yelled at by american CBP and using the developing-nation style airports the US has. Or $2.25k to bypass all that.

And on that note, would I pay the $500 when I fly out of Toronto? Or Shannon, Ireland? It's classified as a domestic flight because of pre-clearance on Canadian or Irish soil for example. So if I were Emirates I would make my routes Dubai to Toronto or Vancouver, passengers would transit into the US by land (at the airport) bypassing the $500 fee and then an alliance flight out to final destination.

So the premise starts to become distance based surchages which already exist in terms of fuel taxes. But then if you just implement rules like "any flight over 6000mi gets $500 tax" watch all the 5999mi routes pop up.

Canada would probably go along with it. I think they are very progressive.

LTLFTcomposite said:

Canada would probably go along with it. I think they are very progressive.

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Go along with what?

An "international aircraft departures tax"?

Or a "distance based surchage"?

A carbon tax?

The first one seems very odd. The last place for technical reasons that we can get rid of fossil fuels in aviation is flights across the oceans. The easiest place to get of fossil fuels in aviation is domestic short hops. Why start with the hardest problem first?

Do we need so many people flying across the oceans?

LTLFTcomposite said:

Do we need so many people flying across the oceans?

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Yes, and they ALL have vital, positive reasons for doing so - just ask them. Some things never change.

LTLFTcomposite said:

Mr Gra, how would you feel about a $500 surcharge per passenger on international flights in and out of the US?

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With how little I fly that'd be fine by me, but obviously business travel would take a big hit. How important that is given video-conferencing etc. remains to be seen. We were supposed to have paperless offices too thanks to computers, but it seems we're generating even more of that than before.