Airlines fly slower to save fuel costs . . .


#1

John Wilen, Associated Press

NEW YORK - Drivers have long known that slowing down on the highway means getting more miles to the gallon. Now airlines are trying it, too - adding a few minutes to flights to save millions on fuel.

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 one Northwest Airlines flight from Paris to Minneapolis earlier this week alone, 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 on those flights alone.

United Airlines has invested in flight planning software that helps pilots choose the best routes and speeds. In some cases, that means planes fly at lower speeds. United estimates the software will save it $20 million a year.

“What we’re doing is flying at a more consistent speed to save fuel,” said Megan McCarthy, a United spokeswoman.

United expects to pay $3.31

a gallon for fuel this year - not much less than what the average American driver pays for a gallon of unleaded at the pump. Southwest, which has an aggressive fuel hedging program, expects to pay about $2.35.

Fliers, already beleaguered by higher fares, more delays and long security lines, may not even notice the extra minutes. The extra flight time is added to published flight schedules or absorbed into the extra time already built into schedules for taxiing and traffic delays.

“If saving fuel costs me a few extra minutes out of my day, then … my inconvenience is nothing,” said Leah Nichols, a television producer who lives in San Francisco and was fresh off a flight at Newark Liberty International Airport, waiting for a train to New York. “I’m cool with that.”


#2

This really makes me mad. Granted, it is only a few minutes on each flight but the reason I fly the airlines is for the SPEED, and TIME. I really don’t care what services they cut in the cabin, but please don’t slow down.


#3

Why do you still fly commercial?


#4

Well, I don’t own a private jet. And for trips over 500 miles, the airlines DO make more sense then flying a GA airplane.

…okay, my new solution, steal an F-16 :smiling_imp: . Now I have all the speed I want…until I have to land it


#5

Realistically, you really think you will notice the difference in the FULL scheme of things. Not too likely from my own experiences.

I’d suspect better things to be mad at :slight_smile: then a few extra minutes of flight.

Heck, take that time and enjoy the extra flight time would be my thoughts.


#6

If 8 minutes makes that much of a differenceto you on a 9 hr flight, I might suggest that your plate is a LITTLE bit too full. Paris to KMSP is about 4300 nautical miles, so figure about a 4 minute slower flight across the continental U.S.


#7

If 8 minutes on an almost 9 hour flight makes a difference to you, I think you may have just a LITTLE bit too much going on. That’s on a 4300 NM flight, so figure on about 4 or 5 minutes on a transcontinental flight in the U.S. Considering that you might spend an hour or more waiting for a gate at LGA, I might suggest that this is a non-issue. Unless you’re the sort of person who gets irate that Cessna is calling the “new” singles the 350 and 400. :wink:


#8

For direct flights that may be true, but on connect flights, even those connecting point to point and not through hubs, not necessarily. For example GA from SF to Jackson Hole is faster, usually cheaper and way more fun, than the commercial connection through Denver.


#9

Ever heard of the slippery slope? I don’t know if it is me but it seems like its getting awfully slippery.


#10

To achieve fuel efficiency in flight, there are four factors at play (speed, cruising altitude, flight distance and gross weight).

Reducing speed alone will not give airlines their maximum savings. I think of many past conservation tricks that airlines played and discuss their
various approaches in my new article “Slow Down to Achieve Fuel Efficiency”.

Please visit my blog aviationinfocus.blogspot.com/200 … iency.html


#11

I was just thinking about this and this reinforces my opinion that planes shouldn’t slow done…what about the higher labor and maintenance costs from longer flights?


#12

Good try, but I’d suspect it might be quite the opposite, parts last longer from lesser stress from the higher airspeeds whether it be mechanical in the engine from lesser engine output to lesser stress on the airframes.

We are only talking about a four minute difference for a flight that covers a continent or eight minutes on an international flight, not your average one hour flight, so what you say above would be very minimal impact when it comes to maintenance and additional hours, far less then offsetting the savings of the cost of fuel that I can see.


#13

It is not so much about long flights. All aircrafts will go through routine maintenance after predetermined hours in flight. However, low speed flying can introduce excessive engine vibrations, which can increase the maintenance costs and reduce the life cycle of a jet aircraft.

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#14

I don’t know of any reason why reducing engine power and flight speed in the 1% range being discussed here will “introduce excessive engine vibrations” or increase maintenance costs or reduce engine longevity.


#15

True, but minutes add up to hours just like these so called “savings” add up over time. Well that’s just my 2 cents.


#16

agree. 1% decrease in speed does not have significant impact.


#17

I fly pistons so only can relate in that respect, but if I get ANY vibration at ANY speed, then there is a problem then just flying slower and I ground my plane accordingly until that source of vibration is found AND fixed.

I would think the same would be for jet engines???

In my eyes, flying slower does not induce vibration of any kind.


#18

Do you ever experience troubles flying lean-of-peak? That can sometimes be harsh on the engine.


#19

I never fly lean of peak. I figure it’s a heck a lot cheaper to replace a fouled plug then an entire cylinder. So, I pretty much fly rich of peak.

I lean on my climbs as I can feel a significant performance improvement then just leaving it rich (POH sez lean as required) Once I find that sweet spot where the plane really wants to climb, I leave it there until I reach cruise or need to milk out a little more performance by leaning a touch more when going above 7000.

I have a CHT and EGT gauge in my plane, and like a car, I keep the needle in the middle, figuring that middle is good.

Once I lower the nose at cruise altitude, build my speed up, then back off the throttle, if I see the CHT and EGT drop, I will lean a touch more, but again, never letting the needles go above the middle value.

With my method above, to date, never had a foul plug.

Engine, naturally will stutter if I lean too aggressively, but having flown this plane for 6 years, it just doesn’t happen that often.

On ground ops, like taxiing, I do lean much more agressively to prevent carbon buildup, and my runup checks will QUICKLY remind me to enrichen the mixture should I happen to forget.


#20

The primary enemy of a turbine engine is heat. Excessive operating temps will damage a turbine long before varied power settings. A turbine runs smoothly throughout its rpm range unless something is out of tolerance…but that’s a whole different problem.