Each green approach saves up to 100 kg of aviation fuel.

While airborne travel and freight transport offer enormous benefits, there are also substantial environmental drawbacks such as increased greenhouse gas emissions. Alternatives exist, of course, but speed and safety often make flying the most practical transportation choice. Perhaps the most obvious way to limit climate impact is improving aircraft fuel efficiency with new technologies and alternative fuels. But it’s also possible to achieve significant gains by analyzing operational routines and flight routes.

LFV Group, the state-owned Swedish company responsible for airports and air navigation services, has long recognized the potential for cutting pollution through streamlined aircraft operation, and has tested a variety of ideas in projects often conducted in collaboration with Stockholm’s Arlanda Airport. The common thread is to look for better fuel efficiency at each stage of the flight, from take-off through cruising to landing.

The Air Navigation Services division at LFV started Project Green Flights in 2007 to explore a variety of measures to reduce emissions and noise from aircraft in Swedish airspace, focusing on cooperation between airlines, pilots, air traffic controllers and airports.

Airplanes use fuel inefficiently on the ground, so simply shortening the taxiing distance from the gate to the runway and reducing idling time pays off. LFV has introduced specialized queue management computer software to limit waiting times. This sub-project, which LFV calls Green Departures, includes optimization of the ascent profile followed by planes as they climb to cruising altitude.

Once planes are in the air, traffic controllers can give pilots the straightest possible routes and avoid unnecessary detours. LFV’s program to shorten routes in Swedish airspace, known as Green Cruise, saves an estimated 5,400 tons of fuel each year, based on reduced flying time of about 10 hours a day. The goal is for 80 percent of all flights to be offered the straight-line routes by 2012.

Finally, landings are based on a Green Approach, which means the plane follows a continuous descent profile down to the runway under optimum throttle. Each green approach to Stockholm Arlanda saves an estimated 50 to 100 kg of fuel. Some 30,000 green approaches since the project began at Arlanda have saved more than 1,700 tons of aviation fuel. As with the shortest-path routing for cruising aircraft, LFV’s has set a goal of offering green approaches to eight out of 10 flights arriving at Swedish airports in 2012.

Article published in February 2010.