GRA wrote: ↑
Thu Nov 14, 2019 6:10 pm
Which is the point being made - first class pax take up more space per pax, thus the a/c can hold fewer people and the energy cost per pax goes up (although it drops some due to the lower weight of pax and fuel AOTBE).
See the comparison chart here for general numbers comparing different modes of travel: https://www.withouthotair.com/c20/page_128.shtml
It seems to be a lot more complex. Longer flights are more fuel efficient per passenger mile.
Empty (EW) plane is 103,872 kg.
Payload is 45,813 kg
Fuel is 73,364 kg
Max takeoff MTOW is 204,116 kg
Max passengers is 375 people, at 100kg for person + luggage that is 37500kg
So on a trip to near maximum safe economical range, MTOW-EW-Fuel = 204,116-73,364-103,872= 26880 kg payload, or 268 passengers max. This is why the longest flights have large business class or first class sections. As a large fraction of the fuel is burned at takeoff and initial climb, and a more direct route is likely traveled, one long flight is likely is more fuel efficient per passenger than two shorter flights. The most extreme example is this:
https://www.qantasnewsroom.com.au/media ... -take-off/
Which isn't economic, as is beyond that maximum safe economical range. Payload had to be reduced to improve range.
Shorter flights are both far less efficient per passenger mile and are more efficient the more people that can be stuffed on the airplane. So yes, first class costs more if there isn't enough freight to fully load the aircraft to maximum payload. Almost the same cost if the aircraft is near maximum payload.
Complex reality doesn't match simplistic statements.
A train might be almost as fast on a shorter flight, much more efficient and allow much more space per person to reduce the stress of travel.