How much do all the loose items on board a long-haul airliner weigh (passengers and crew excluded)? After removing, weighing and cataloging everything not bolted down in the cockpit, cabin and cargo hold of an Airbus A340-300 just returned to Frankfurt from Rio de Janeiro, Lufthansa can say the answer is - almost 4 metric tons.
After a team of almost 40 people spent more than 7 hours stripping the A340, Lufthansa plans to use the data to decide what should remain in board, and in what quantity. Although it does not yet know precisely what can be eliminated, the airline believes up to10% of the items cataloged could be stripped from the aircraft, and estimates every 100kg of weight removed would reduce an aircraft's fuel costs by €2.6 million (almost $4 million) a year.
Lufthansa says the weigh-a-thon is one of 400 fuel-saving projects under way at the airline. Another involves flight trials of drag-reducing riblets to test their durability in service. Riblets are microscopic streamwise grooves that reduce airflow turbulence and resulting skin-friction drag. Germany's Fraunhofer Institute has developed a way to emboss the grooves into the aircraft paint, and two Lufthansa A340-300s will fly through the summer to see how well the surface lasts.
Eight 4 x 4in test patches have been placed on the fuselage and leading edges of the wing of each A340 as part of the Multifunctional Coating research project. Lufthansa says research suggests, when applied to most of the aircraft's surface, riblets could reduce fuel consumption by 1%. But it won't make economic sense if the aircraft has to be stripped and painted more often because the grooves wear down.