Aviation knows it has to be efficent especially with the price of oil
I think not.
Examples-
Aircraft asking to hold at the initial apparoach fix rather than land because they've arrived early and the airline doesn't have handling staff available.
Regulary 15-20 minutes airborne holding to get into Heathrow.
Aircraft offered a 40 minute delay at Manchester to avoid 40 minutes holding at Bovingdon still gets airborne and takes the delay in the sky.
Tankering fuel because of fuel price differentials between departure and destination.