View Full Version : Fuel saving tips

10th Oct 2008, 10:35
Specific to the A320, please let us know how you save fuel

10th Oct 2008, 11:06
Regular engine and aircraft washes. Reduce the amount of newspapers and other give outs, do a survey and check what comes back and unused and adjust the loading of items accordingly. Empty the holds of debris left over from previous loading, it may seem small fry but it all adds up, 1 engine off for long taxying at large airports. Cut down on cabin crew. Closely monitor the extra fuel pilots put on above the planned. Adjust the water in the water tank for shorter journeys were you have a reliable source for topping up at outstation as a standby. Buy more serviceable GPU's and stop running APU's all night or on long transits. Dim cabin lights after starting aircraft for service and before pax get on to save heating the cabin that you then have to cool to get rid of the heat for passenger comfort. Check aircraft for air leakage and fairing profile. :D

11th Oct 2008, 21:46
:8 Try to get and read this:

A FLIGHT" by Airbus.:8

Old Smokey
12th Oct 2008, 09:52
Excellent advice from allthatglitters,to add one very significant saving -

The sooner that you can delete the 250 KIAS speed limit at low altitudes and accelerate to normal Econ Climb speed, the better for fuel burn. (Technical explanation available if desired).

On the B777, deleting the 250 KIAS speed limit at 5000 feet and increasing to a more typical 310-320 KIAS climb speed saves about 500 Kg per sector.

Of course the degree of saving depends upon the aircraft size, and the differential between 250 KIAS and your normal climb speed.

We operate aircraft from the A380 down to the Learjet 45, and even on the Learjet, early 275 KIAS climb Vs 250 KIAS climb saves about 100 Kg, significant for an aircraft of that size.

Of course, such a speed increase typically requires ATC approval, and sshould be consistant with safe operating procedures.

Standing by for incoming flak from Canuckbirdstrike.


Old Smokey

12th Oct 2008, 14:03
Regarding climb speed, in a 747 Classic we always request higher climb speed.
We generally request V2+100 initially, heavy T/O would be about 275-280 KIAS.
ATC almost always approves, even in USA airspace, they know we need it.
Bear in mind that at heavy weight, our climb speed is 330-335 KIAS.
In South America, they never object. Just say what speed you plan to climb.
Try also to load aircraft with an AFT CG, besides your weight savings.
Then if you use the old paper cruise tables, see what FL is most efficient.
Still some pilots believe that MAX FL is best fuel economy. Absolutely NOT.
For the old 747, generally the best is 2000-3000 ft below maximum FL.
I personally look at the specific range NAM/1000.
Happy contrails

P.S. Lean the mixture... :E

13th Oct 2008, 03:21
What about the 744? What's your take on the cruising level if ATC can't give you the optimum level? Higher or lower, say, if the winds are the same?

Also, how are airlines operating with regards to cost index these days? Everyone going slow with a high nose attitude, like what I have to?

13th Oct 2008, 03:29
Closely monitor the extra fuel pilots put on above the planned.

Now that one raised my brows - fortunately I don't have to work for you...


13th Oct 2008, 06:01
A technical explanation is available

A technical explation is always welcome please

Pilot Pete
13th Oct 2008, 09:50
Use ground power whenever available and turn the APU off. If you need the APU for ground power, then try to turn the bleed off from the APU if you don't need aircon due to ambient temperature. Even just saving on bleed air requirement from the APU will save a significant amount of burn.

Use an efficient flight planning system that gives the pilots confidence in the flight plan fuel figure. This breeds a 'culture' of confidence and will allow pilots to trust the plan figure and not just add on a few hundred kilos here and there due to perceived innaccuracies.

Never question the commanders decision to load what he feels is needed, but look at trends and work with captains to get to their underlying logic. If their logic is sound then great. If training input could be beneficial then give that input during checks. There is no point 'telling' a captain that he should take less fuel, you need to get him to understand and trust the planning system to have faith that it is accurate and sufficient (ammended by him for on the day 'real world' foreseable increases).

On that note, most pilots have a culture of looking for reasons to add fuel to planned figures, to create that buffer. Why not be more pragmatic and look for things which are likely to reduce your burn also? I am talking mainly shorthaul around EU here, as you are never far away from suitable alternates and my company would prefer us to not load unnecessary fuel and if things don't work out as planned and we need to divert for a tech stop, so be it. They would NEVER question your uplift, and they would NEVER criticise you if your planning and excecution were reasonable but things just conspired against you. It leads to a mutual culture of trust and is a benchmark for efficient fuel planning. An example where fuel can be saved with us is going to Malaga. The flight plan system always plans on the longest STAR, which is some 70nm longer than the shortest, which is the one most usually flown.

In good met conditions use a 'fuel' alternate as your first destination alternate, which can be much closer to your destination than perhaps the 'commercial' alternate (where they would ideally like you to divert to if you didn't get into destination). If the diversion risk is minimal this can save significant amounts of burn and the company accept that if you do end up diverting then you won't be going to their 'more commercially desirable' airport and it will cost them a bit more.

Single engine taxy in wherever suitable. Again, it needs a culture change, but if you can get that and make it SOP to do unless there is a reason not to, you will save huge amounts of fuel over a fleet, over a year.

A huge issue at the moment is ATC. In busy airspace like the UK it is often difficult to geta continuous idle power descent from ToD to short final. This is being looked at by NATS and the airlines to see if anything can be done, but CDA approaches are another area that can save significant amopunts of fuel.

To achieve the above pilots need to plan their descents and energy manage to the best of their ability, which comes from having correct information to base that plan on. Ensure that you program the FMC with the most 'likely' routing to happen to you, rather than just what the flight plan has on it, which comes from route knowledge. Early descents due to ATC can be better managed in my experience - I often see pilots descend early to reach a certain point at a certain level (ATC restriction), only to be given further descent before reaching that point and they continue to descend at idle thrust beyond the limitation when they are now low on profile and increasing burn later on at the lower levels.

Oh, and carry a smaller torch in your nav bag.;)


13th Oct 2008, 19:02
Old Smokey:

Where did you get your savings numbers from? Anectdotal or is every flight monitored for speed and fuel consumption?

Notwithstanding the bird strike issue, it is interesting that you raise the issue of high speed flight below 10,000 feet as a "significant" fuel savings opportunity. The data does not support this. Specifically, the pure optimum climb speed for an aircraft is specific to the aircraft engine combination adjusted for actual GW and atmospherics. In many cases the ATC system cannot accomodate every different optimum climb speed for the myriad of aircraft operating. What ends up occurring is that all aircraft end up operating at a "compromise" speed that penalizes some or all aircraft. Additionally, the incremental time/fuel savings you quote appear far higher than any of the data I collected when conducting extensive research and writing a complete risk analysis report on this issue.

It must be clearly understood that current aircraft and engines were not designed or certified for bird strike protection for high speed flight at low altitudes where the risk of striking larger flocking birds is high. When operating at high speed at low altitude you increase the probability, exposure and severity of the risk of a bird strike. There are lots of birds between 3 and 9 thousand feet and they will be larger flocking birds.

If you want to save fuel there are many far more effective strategies that do not involve the incremental safety risk of high speed flight below 10,000 feet. Here are some of the many that I have persoanlly worked on as a fuel efficienmcy technica lpilot for the airline I fly for.

For Flight Planning The Real Key to Efficiency:
1. Risk based alternate selection policy
2. Statistical fuel analysis for boarding of additional fuel by route segment
3. City pair Cost Index selection
4. Integrated full vertical and lateral optimization flight planning system
5. Structured pilot additional fuel planning tools

For Flight Operation:
1. Minimizing APU use, but not at the expense of cutomer care
2. Engine out taxi
3. Appropriate flap selection for takeoff
4. Correct climb profile based on runway direction and on course track
5. Correct use of Optimum Altitudes from a robust flight planning system rather than relying on FMS Optimum altitudes.
6. Adherence to Cost Index climb, cruise and descent profiles
7. Prudent use of short direct routing changes to smooth a flight plan generated toute and avoiding long direct rotuings that negate the value of good flight planning.
8. Correct descent optimization by ensuring all descent winds are loaded into the FMS
9. Decelerated approaches where flap/gear selection is dependent on managing the aircraft energy to achieve a stabilized approach by no l;ater than 1,000 ft. AGL rather than based on fixed distances to the FAF.
10. Reduce flap landings
11. Idle reverse on landing on carbon braje aircraft.
12. Engine out taxi to the gate.
13. Minimum use of the APU after gate arrival.

All of the above are "fuel saving tools", and like any tool, choosing when and how to use them requires thought and careful analysis of all the specific day-of-flight conditions to ensure that safety is not compromised in the pursuit of fuel efficiency.

The last and most critical element required to achive fuel savings is an integrated approach that has good policy and tools supported by a comprehensive pilot and flight planner training program. Well trained and informed employees will make better fuel efficiency decisions.

High speed flight below 10,000 feet offer very little value and presents significant risk..

14th Oct 2008, 00:42
Use "OP DES" for all descents - its just 6kgs per min per engine. I can't get a lower burn unless I turn the engine off...!!!!

During a one hour flight, BFS - LGW, I can save 200 kgs from KEPAD to HOLLY. Adjust the selected speed to control rate of descent and expect bottles of fine vintage left in your drop file from the Base captain.

14th Oct 2008, 06:15
We operate some long sectors (for the aircraft type) from Europe back to NY on our 757's.

You can be hard pressed to make it back non stop with winter headwinds sometimes.

Amongst other things, on such a flight I will start with a full power take off switching to max continuous power at thrust reduction until it 'washes' out to equal climb power.

This gives you the quickest possible climb to cruise altitude where you can start burning less fuel sooner.

I have found it quite effective, saving a worthwhile amount on those 'challenging flights'

Of course, I only use that technique when, even departing with full tanks, arriving with sufficient fuel reserves looks doubtful.

Would not want to cause undue wear and tear on the lovely RB211 !