An unconventional solution to growing aviation emissions has come from Cranfield academic Ian Poll: build more airports and, crucially, longer runways.
The professor for aerospace engineering at Cranfield University spoke at the Westminster Energy, Environment & Transport Forum in London yesterday. He argues that air travel was a good way to reduce transport emissions and that aviation should thus be considered part of the solution rather than a source for the pollution problem.
“We don’t want China and India to build roads and railways,” said Poll with a view on the aviation industry’s main growth markets. Air travel has just to be made more efficient.
The problem with aircraft as we know them today is that they are apparently based on a historic compromise that goes back to the early days of air travel after World War II. The first-generation jetliners determined the fundamental setup of airports today, particularly with regard to runway length and departure/arrival procedures.
Poll argues that modern aircraft have, essentially, too large wings. Their size is governed by the weight of the aircraft and the required speed during takeoff and landing. This determines in return the optimal cruise altitude and speed.
If the runways were longer, aircraft could fly faster during departure and approach, and thus require smaller wings than today’s models. Their cruise speed would be slower, but they could travel efficiently at lower altitudes and thus avoid contrails.
To illustrate his argument, Poll said that the noise reduction departure procedure for the Airbus A380 at London Heathrow apparently led to a 1% higher fuel consumption during cruise.
Maybe Professor Poll’s research team should build a demonstrator version of this ‘clipped wing’ aircraft that can be scaled down sufficiently to take off from Heathrow’s 3,900m (12,800ft) runway.
By Michael Gubisch, Flightglobal’s MRO reporter