Southwest Airlines started flying slower about two months ago, and projects it will save $42 million in fuel this year by extending each flight by one to three minutes.

On a Northwest Airlines flight from Paris to Minneapolis this week, flying slower saved 162 gallons of fuel, saving the airline $535. It added eight minutes to the flight, extending it to eight hours, 58 minutes.

That meant flying at an average speed of 532 mph, down from the usual 542 mph.

"It's not a dramatic change," said Dave Fuller, director of flight operations at JetBlue, which began flying slower two years ago.

But the savings add up. JetBlue adds an average of just under two minutes to each flight, and saves about $13.6 million a year in jet fuel. Adding just four minutes to its flights to and from Hawaii saves Northwest Airlines $600,000 a year.

From my recent transatlantic flights, another dodge they are using is hunting for the jet stream to either get more tail wind going east or less headwind going west. My most recent trip Chicago to London was the fastest I ever had.

Eric

This is really interesting information. Thanks for sharing.

Does the same concept of going slower and saving on fuel work for automobiles as well?

Southwest plans to activate autothrottle in their airplanes soon for a more economical flight.

Eric: The article mentioned that AA is working closely with flight controlers to obtain the most favorable winds possible for each flight.

Mike: I'm not sure if you're serious about the car question or not. But yes, driving slower saves fuel. The article did point out that flying too slow also increases fuel consumption.

Joe: Kind of like cruise control? Is this seperate from the autopilot?

I'm surprised they haven't gone to taxxing with one engine (two engine plane). Jet engines are relatively efficient at altitude above 34k to 41k due to the thickness of the air and upper winds.
Where they consume an ungodly amount of fuel is taxiing to and from the runways.

I remember being in the cockpit of a Dc-9 taxiing out to the runway and I could see the fuel consumed gage and the plane used 250 lbs of fuel in about 10 minutes.

That 250 pounds is a little over 30 gallons for those of you who don't want to do the math. Divided by two engines that a DC9 has plus the APU running, it's probably under 15 gallons per engine depending on when they reset the fuel used indicator and how long the APU was running before engine start. So a little more than a gallon per minute based on Oneboaters story.

Of course the highest fuel flow is those short times of high power settings on the ground. If you have a pilot that lands the plane, puts the engines in max reverse until the plane almost stops, they are burning a lot of fuel. If they hold the nose up, pop the reversers and go easy on reverse thrust, they are saving fuel. That's often airline policy technique as there are things that go wrong transitioning from flight to taxi speeds.

There are no laws against shutting down an engine for taxi. Again, it's up to the airline policy. First of all, they must remember to restart it. And pilots have forgotten to start one of their engines. It's usually on a plane with more than 2 engines. A two enigne plane with one engine shut down loses half of it's main air conditioning, half of it's main electric power supply, half of it's main hydraulic supply to power stuff like brakes, steering, controls, flaps, slats, etc. Airlines are more likely to allow single engine taxi after landing than before departure because the pilots checklists are already configuring the plane for engine shut down. It's still pretty dangerous if they lose steering and brakes heading towards the terminal.