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Slowing speeds to save on fuel costs

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RJL

Well-known member
Joined
Feb 21, 2002
Posts
68
Slowing speeds to save on fuel costs

Any other companies telling pilots to slow it down to save fuel latley? Please let me know or send me a private message. I heard a memo was sent to other pilots too.

Slowing it down may save a little $$$ on fuel, but it always seems to end up costing us by making the customers angry from late arrivals, delays, etc.

Some of my pax also seem to watch the clock alot. They always ask when the flight is running a little longer than usual (usually due to ATC, weather, etc.).
 
Several months ago, our company (CommutAir) issued new a new normal cruise power setting in an effort to save fuel. (On our Beech 1900s, we've gone from 3000# and 1450RPM to 2750# and 1400RPM.) In principle, it's worked great. It's saving our company significant fuel and money. But it could save so much more.

On legs that are properly blocked, I'm happy to do it. But on legs that are blocked too short, I don't slow, because our passengers are making plans around that schedule. When I'm swapping airplanes at the next station on a short turn, I don't slow. Our training dept. has noted that, after several months of declining per-hour fuel usage, it's starting to go back up, which I attribute to inadequate block times combined with short turns. Don't make me eat into my lunch break. :D
 
The aircraft I fly is advertised at a speed equivalent to roughly 460KTAS (M.80). The owners in the back know this, and expect it to be flown. Besides, they pay by the occupied "hour", so it is in their interest to go fast. And, if we're late for any reason, they expect me try and make up some time.

I won't slow down.
 
We've slowed...the CP says that we are showing some fuel savings...how much? I don't know. Instead of max cruise power and seeing .82-87, we are now flying at .80. Adds a few minutes to total flight time, but not much. The owner's don't seem to notice or care.
 
.92 all day long. Ferry flights, pax flights. The plane is built for speed. My schedule is built at max speed. Disptach might say LRC but IJET has me going full speed.

Plus fuel is cheap when compared to the hourly cost of the plane.

Yeah you might be saving fuel but you're putting a lot more time on the airplane and the engines.

No thanks go fast.
 
THANK YOU DIESEL!!!

Let us theorize an average fuel burn saving per hour of 300# total with an average speed impact in still air of 25 KTAS reduction.

In a 250 KTAS aircraft this is one additional tenth ".1" flight time.
If this 250 KTAS a/c costs $750 per hour to operate, this equates to increased cost of that flight by $75.

300# of fuel or 45 gallons (rounded) with an average increase (last year) of 75 cents per gallon is only saving ON GAS $35 dollars per hour, BUT increasing the overall cost of the flight by that $75 from more time on the a/c.

You would have to be paying over $2 per gallon ABOVE normal in order break even on the offset in increased operational costs. This is true for any Corporate/Charter Aircraft. Higher speed, higher fuel burn will incidentally have higher operational costs and inversely lower performance the more the fuel flow is reduced.

100-1/2
 
Hey CA1900,

Do you mean to tell me that Joel and Terry are still doing a bang up job over there?!? Do yourself a favor. Get the time and get the hell out. That place is a dump, run by high school drop outs and criminals.

Max power, takeoff to 4 mile final. That was the rule way back when.

Good luck.
 
100-1/2 said:
THANK YOU DIESEL!!!

Let us theorize an average fuel burn saving per hour of 300# total with an average speed impact in still air of 25 KTAS reduction.

In a 250 KTAS aircraft this is one additional tenth ".1" flight time.
If this 250 KTAS a/c costs $750 per hour to operate, this equates to increased cost of that flight by $75.

300# of fuel or 45 gallons (rounded) with an average increase (last year) of 75 cents per gallon is only saving ON GAS $35 dollars per hour, BUT increasing the overall cost of the flight by that $75 from more time on the a/c.

You would have to be paying over $2 per gallon ABOVE normal in order break even on the offset in increased operational costs. This is true for any Corporate/Charter Aircraft. Higher speed, higher fuel burn will incidentally have higher operational costs and inversely lower performance the more the fuel flow is reduced.

100-1/2

Exactly! In the XL, the fuel savings with LRC compared to HSC are minimal compared to the increase in leg time. It's always HSC with owners on board. I usually go HSC on ferry legs. 99% of the PIC's I fly with will do the same on the ferry legs. The other 1% insist on flying NCT or LRC per the release. Depending on how anal the guy/gal is, I'll run the numbers for the leg and show him/her that we really aren't saving much.
 
Fozzy said:
Hey CA1900,

Do you mean to tell me that Joel and Terry are still doing a bang up job over there?!?

Yeah, pretty much. :D When they aren't involved, things seem to go smoother.

Do yourself a favor. Get the time and get the hell out.

Ummm... DUH! We're all trying to get out. We're working on it, believe me. This isn't meant to be a career destination.

Max power, takeoff to 4 mile final. That was the rule way back when.

Still is, when I'm driving. It's amazing how much fast you'll drive when there's beer on the other end. :D
 
Hey where the hell is my ESOP money? ;)

Who is D.O. now? I heard Vanda bugged out a few months ago.

Good luck in the job search.
 
Thanks for the good wishes, I'll need it!

Vanda did indeed leave us to work for an operator in Burlington. I'm sure the long commute (lol) must have worn on her. Henry W. is now our D.O.
 
100-1/2 said:
THANK YOU DIESEL!!!

Let us theorize an average fuel burn saving per hour of 300# total with an average speed impact in still air of 25 KTAS reduction.

In a 250 KTAS aircraft this is one additional tenth ".1" flight time.
If this 250 KTAS a/c costs $750 per hour to operate, this equates to increased cost of that flight by $75.

300# of fuel or 45 gallons (rounded) with an average increase (last year) of 75 cents per gallon is only saving ON GAS $35 dollars per hour, BUT increasing the overall cost of the flight by that $75 from more time on the a/c.

You would have to be paying over $2 per gallon ABOVE normal in order break even on the offset in increased operational costs. This is true for any Corporate/Charter Aircraft. Higher speed, higher fuel burn will incidentally have higher operational costs and inversely lower performance the more the fuel flow is reduced.

100-1/2

It's refreshing to know I'm not the only one who thinks like this...wish I had the power to effect change, but that happens at a pay-grade much higher than mine. :rolleyes:
 
High Altitudes worked great for me, FL220 from ALB to ROC Fuel flow set to 350pph (no specific torque setting) per side at cruise and climb at the recommended climb schedule. total burn about 700 pounds. Same holds true for BOS to BTV etc.. and generally speaking don't worry about the headwinds, your trade off point is about 3 knots of headwind per 1000' of altitude, in otherwords I would have gladly accepted a 65 knot headwind at FL 220 instead of a 40 knot headwind at 8000




CA1900 said:
Several months ago, our company (CommutAir) issued new a new normal cruise power setting in an effort to save fuel. (On our Beech 1900s, we've gone from 3000# and 1450RPM to 2750# and 1400RPM.) In principle, it's worked great. It's saving our company significant fuel and money. But it could save so much more.

On legs that are properly blocked, I'm happy to do it. But on legs that are blocked too short, I don't slow, because our passengers are making plans around that schedule. When I'm swapping airplanes at the next station on a short turn, I don't slow. Our training dept. has noted that, after several months of declining per-hour fuel usage, it's starting to go back up, which I attribute to inadequate block times combined with short turns. Don't make me eat into my lunch break. :D
 
100-1/2 said:
THANK YOU DIESEL!!!

Let us theorize an average fuel burn saving per hour of 300# total with an average speed impact in still air of 25 KTAS reduction.

In a 250 KTAS aircraft this is one additional tenth ".1" flight time.
If this 250 KTAS a/c costs $750 per hour to operate, this equates to increased cost of that flight by $75.

I'm affraid it's not quite that simple, because you don't buy the things that equate to aircraft operating expenses by the hour or even a tenth of an hour. Most of the elements that effect the $750/hr cost you quote are purchased annually, so things like insurance, pilot training, buying the aircraft, hangar space, admin staff and maint are fixed expenses and therefore flying an extra .1 a trip does not really cost you ANYTHING, bottom line saving fuel saves you money. Taking that a step further it could be argued that running the engines cooler will increase the life of the engines and where there is a fixed TBO it will decrease the overhaul cost.

In a nutshell the $750 an hour is not an absolute figure, it's a planning number based on the number of hours you expect to fly the aircraft. If you only fly the aircraft let's say 10 hours a month you might have to work with a number of $6000 an hour. If you increase the number of hours above what you are flying now, let say 30% you would expect to see the hourly rate to drop to maybe $650 an hour.
 
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A big benefit to flying higher mostly and slower is the eventual harm to the enginges. I've talked to several mechanics who say there is a big difference at overhauls in what needs to be replaced. The higher and slower you go the lower the ITT's and it can make a big difference. I know of companies that extend their TBO's based on proof of this. i'm not saying it's right but it does add to the equation.
 

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