AIRCRAFT ARE emitting more nitrous oxide into the atmosphere than expected, although the resulting atmospheric damage remains insignificant, says the German Aerospace Research Establishment (DLR).
In an interim report on its research into harmful substances in aviation, the DLR says that jet aircraft worldwide emit 2.8 million tonnes of nitrous oxide a year, exceeding all predictions and contributing to the greenhouse effect.
Project chief Ulrich Schumann stresses that the calculated contribution of aircraft exhaust gases to the greenhouse effect remains so low - at 0.1°C - as to be un-provable through measurement.
DLR scientists add that satellite data show that condensation trails, which encourage the formation of cirrus clouds, have been responsible for a 0.4% increase in cloud cover over Central Europe.
The researchers say that further development of cleaner engines should allow total annual NOx emissions to be kept constant, even though air traffic growth will double annual fuel consumption, which today stands at 180 million tonnes, in the next few years.
Lufthansa says that its 1994 fuel-efficiency figures are its best ever. It used 5.5litres (1.45gal) of kerosene per 100 passenger kilometres in 1994 - less than most cars, claims the airline. Lufthansa's fuel consumption has fallen by 5.7% since 1991, to 3 million tonnes. Fuel consumption per passenger has halved since 1970, it says, and predicts that it will halve again in the next ten to 15 years.
Source: Flight International
