Diminution des consommations par optimisation des procédures et plans de vol

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.

L'atterrissage "vert" ou le vol plané au service du climat

A 9.000 mètres d'altitude, réacteurs au point mort, l'Airbus amorce une descente silencieuse de 25 minutes en vol plané pour un atterrissage "vert" sur l'aéroport de Stockholm.
En planant à travers le ciel blanc de l'hiver suédois, le commandant de l'A321 Henrik Ekstrand a épargné 300 litres de kérosène à sa compagnie charter Novair, permettant de réduire les coûts et les émissions de CO2.
La compagnie suédoise a bouclé cette semaine une série de dix vols expérimentaux, les premiers en Europe à combiner un atterrissage moteurs au ralenti avec une approche dite "en courbe", réduisant de plusieurs kilomètres la distance parcourue, hors des habituels longs couloirs aériens.
Ce type d'atterrissage "vert" qui utilise la navigation par satellite est en plein essor dans les pays nordiques et notamment en Suède, sous l'impulsion de la première compagnie scandinave SAS et de l'aéroport international de Stockholm-Arlanda.
"C'est très silencieux, on note vraiment la différence au niveau du bruit. C'est beaucoup plus confortable, sans à-coups", note Mathias Klarowski, un étudiant allemand en aéronautique de 23 ans, invité à bord grâce à son université de Stockholm.
Dans une Suède très soucieuse d'écologie, SAS a commencé en janvier 2006, à Stockholm, ces atterrissages à faible consommation de kérosène, qui rallongent de quelques minutes la durée des vols mais qui sont moins coûteux et moins polluants en termes de bruit et de C02.
"Bien sûr, je pourrais voler plus vite", a expliqué à l'AFP Ulf Martinsson, un pilote de SAS. "Mais le gain de l'approche verte vient du fait qu'on va plus lentement", souligne le pilote.
Le type d'atterrissage mené par Novair est plus subtile car il combine la route plus courte de l'approche par GPS avec un atterrissage moins gourmand.
"C'est le début d'une évolution d'un système fondé sur la réglementation vers un système fondé sur l'efficacité", se félicite Lars Lindberg, président d'Avtech, la société aéronautique suédoise qui dirige le projet.
Depuis juin dernier, l'expérience menée sur plusieurs vols commerciaux avec passagers a permis d'économiser en moyenne 165 litres par vol avec divers types d'appareils.
Cette technique, impossible en cas de mauvaise visibilité, favorise également une approche mieux synchronisée, permettant près d'une demi-heure à l'avance de savoir quand l'avion se posera, à une dizaine de secondes près.
L'aéroport international de Stockholm-Arlanda, où plus de 2.000 atterrissages "verts" ont été menés depuis janvier 2006 --le plus souvent par SAS-- s'est fixé un objectif de 80% d'atterrissages de ce type d'ici à 2012, afin de réduire les émissions.
Quelque 17 autres compagnies, comme Air France, Nav Portugal, TAP Portugal, Icelandair ou Iberia, ont également mené des essais, selon le Sesar, l'organisme européen chargé de coordonner l'espace aérien en Europe.
Les compagnies aériennes, en difficulté à cause de la crise économique mondiale, sont sous pression pour réduire leurs coûts mais aussi leurs rejets polluants.
Selon le Groupe intergouvernemental d'experts sur l'évolution du climat (Giec), le transport aérien représente 2% des émissions de CO2 et 13% des émissions liées au transport, une proportion en constante augmentation.

Qantas deploys RNP technology on Melbourne 737-800s
By Greg Waldron

Australia's Qantas Airways has deployed required navigational performance (RNP) technology on all its Boeing 737-800 aircraft that fly to and from Melbourne, helping it to save fuel.

RNP uses GPS to help pilots optimise flight approach and departure tracks containing curves and vertical profiles that could not be flown accurately using ground-based navigation aids, says Qantas's group executive for government and corporate affairs, David Epstein. "This results in shorter flight paths, limiting the amount of fuel emissions we are generating."

Epstein says RNP technology enables aircraft to land in poor weather at some airports where previously they could not have done. "It is often the case that our RNP-equipped 737s can land in bad weather, where other aircraft can't."

Singapore Airlines 747-400 completes first multi-sector ASPIRE flight

A Singapore Airlines 747-400 yesterday completed the fifth ASPIRE (Asia Pacific Initiative to Reduce Emissions) demonstration flight and the first multi-sector flight in the program, flying a Los Angeles-Tokyo Narita-Singapore routing and achieving about a 5%-6% fuel/carbon dioxide emissions savings compared to a usual SIA flight on the route.

The airline said total fuel savings were calculated at 10,868 kg. while CO2 reduction was 33,769 kg., both exceeding the goals for the flight. Flight time was lowered by about 30 min. The flight was achieved through a collaboration among SIA, US FAA, the Japan Civil Aviation Bureau and the Civil Aviation Authority of Singapore, which Monday became the fifth air services provider to enlist as an ASPIRE signatory.

SIA Senior VP-Flight Operations Gerard Yeap, briefing reporters at the show, explained that the 747-400 operated a "red carpet flight" in which every conceivable measure was taken to allow it to fly as efficiently as possible. "Look at it as an aspiration of what we'd like to achieve in a green flight," he said. "It shows it can be done."

Ground electrical supply was used instead of the APU to power the aircraft at all three airports. The amount of fuel onboard "was fine-tuned half-an-hour before flight, ensuring a better match with the actual aircraft takeoff weight," SIA said. The 747-400 was allowed to make an "unrestricted climb" following takeoff and used a continuous descent approach at SIN. The airline said that "the bulk of the fuel savings. . .came from using a User Preferred Route generated from the flight planning system Lido/Flight from Lufthansa Systems." Yeap explained, "Based on the latest weather at hand, the UPR is the most efficient route for the aircraft to fly compared to an existing predetermined route."

The -400 used the FreeFlight module of the Lido/Flight solution, which Lufthansa Systems noted "opens up almost unlimited options to calculate the most-efficient routing," adding that the system uses a "highly complex procedure of calculating the most efficient trajectory in terms of distance, flight altitude, wind direction and speed."

Yeap said FreeFlight meant the aircraft was "not bound by traditional airways. . .[or] ground-based routes." He said he hoped the success of the ASPIRE flights will encourage governments, airports and air service providers to invest in modernizing infrastructure. "Many airports in use today were designed in the days of the 707 and meanwhile aircraft technology has advanced by leaps and bounds," he said. "There are regions in the world where, for one 1-hr. flight, you have to do 10 heading changes." Relying more on satellite-based navigation and using the procedures employed in the ASPIRE flights "easily" could increase system efficiency significantly, he declared.
by Aaron Karp