How to burn 18.4% less fuel and live. Really.
By David Learmount on November 5, 2009 3:13 PM | Permalink | Comments (3) | TrackBacks (0) |ShareThis
Courtesy of Oxford Aviation Academy and SAS at OAA's Stockholm base, I have just flown an A320 twice from Gothenburg to Copenhagen, with identical weights in identical conditions both times.
But, by adopting a few modified procedures the second time, we used 18.4% less fuel.
Don't try all these tricks on your next trip without having a word with your ops and training standards people, because even SAS, which has been working for a few years with OAA to develop "Eco-Piloting" techniques and training, has only just got there, and has not yet begun the process of transferring the new tricks onto the line.
If you want to learn about the techniques SAS/OAA have been trialling, register for Flight International's Pilot Best Practice/Crew Management Conference in London at the end of this month and you can talk to Per de la Motte, OAA's Director of Training, Nordic region about his secrets.
Back to my two short trips.
Given that, on the first trip, my mentor in the right hand seat, OAA's fuel-efficiency guru Peter Fogtmann, ensured that we used normal SAS/A320 SOPs and standard routeing with absolutely no shilly-shallying, I wouldn't have thought a fuel saving of 18.4% was possible. But its what we did. Since it's only a 25min hop, 18.4% translates as a 320kg fuel saving, which may not sound much - but what a percentage! Save that every trip for a year and you're talking big bucks and dramatically reduced emissions.
Of course Peter and I are in a simulator, but it's a Level D FFS, so the figures we get should represent the truth, as near as dammit.
The first trip was done the way any good line pilot would do it, so I won't bore you with that. But here are the differences applied on the second trip:
•Reduced the cost index from 30 to 7 in the FMS;
•Chose Malmo instead of Gothenburg as the alternate, which meant we could carry 450kg less fuel;
•APU was started only moments before pushback;
•Single-engine taxi (using No 1 engine). APU was shut down once No 1 was established and checked;
•No 2 was started with 3min to go to line-up for take-off;
•Take-off was carried out with flap/slat 1 instead of 2, and packs off;
•Power levers retarded to "climb" detent at 800ft (instead of 1,500-3,000ft), and acceleration initiated at that point;
•Request for optimum speed below 10,000ft accepted, and continued at 305kt (opt) instead of sticking to standard 250kt;
•Request direct routeing at every opportunity (in this case the routeing was almost direct anyway, so there were no benefits there);
•Input forecast or actual winds rather than standard seasonal;
•Initiate descent at a carefully estimated point beyond normal TOD because continuous descent approach was likely to be available;
•Flap 1 selected at glideslope intercept; flap 2 at 2,000ft; gear down just before 1,000ft; flap 3 selected just before 500ft (would be 1,000ft in IMC); land with flap 3 instead of 4;
•Idle reverse during landing run;
•3min after touchdown, No 2 engine shut down; single-engine taxi to stand.
Yes I know you wouldn't be able to do all those things on many regular trips, and hardly any of them in busy terminal areas during the winter, but just doing some of them when you can provides a benefit that makes a difference. Yes I know you have to consider icing procedures in unkind weather, but sometimes the sun shines.
SAS and OAA, who are making this kind of expertise a speciality, say it's about a mindset. A mindset that hasn't been examined critically for a long time, with the result that there are lots of treasured beliefs out there that are effectively urban myths.
18.4% de gain sur un saut de puce en optimisant les procedures au roulage, au décollage et à l’atterissage principalement.
Plus optimisation du plan de vol !
Présenté comme ça 18.4% est probablement un optimal pour un tel trajet court. La proportion de réduction sur un trajet plus long serait probablement plus faible.