Hey guys, seriously, I am collecting wisdom for a project.
I mean things like PBN, curbed, green, approaches, idling on gps instead of beacons, and not so curbed while en route, but straight between destinations. Also curbed takeoffs on GPS to reduce noise.
More: weight reduction in general, such as better ways to distribute tax-free than onboard. Maximize cabin factor, invest in finding better fuel, cīmon, letīs pack this...
Then, seriously, there STILL is nothing that will make an airline "green"! As I and a couple others have pointed out, it is inherently an "ungreen" industry.
There is very little an airline can do in flight, because of ATC and other regulations. "Noise reduction" profiles already cause more fuel to be burned on takeoff, and ATC interference in published arrivals and approaches already cause more fuel to be burned in the descent.
How much less energy is used if air conditioning and electricity is provided by a ground station instead of an APU? Just because the energy cost/accounting is transferred elsewhere doesn't make it "greener."