What would be the difference in time and fuel consumption for a flight that had no waiting in line for takeoff, no waypoints, and with a …
Answer by Thomas Zerbarini:
In general, from your question (assuming a jet):
- Immediate pushback, taxi and takeoff would save fuel (300 to 1000 lbs)
- straight line navigation would be marginal in fuel savings. Almost a non-issue as long as the flight is general not turning more than 20 degrees. Long distance flight benefit from great circle route planning (the shortest distance route on a sphere).
- A continuous descent would consume a lot of fuel. the best descent profile is a 4-5 degree descent angle and staying aloft at cruise for as long as possible. In this scenario you are essentially descending with idle thrust.
So, the best fuel savings scenario is"
- No delay Taxi to takeoff
- Best rate of climb to cruise
- Stay aloft in cruise as long as possible
- Fly straight and/or great circle routes for long distance.
- Fast descent to landing.
- No delay taxi to gate.