Europe took a key step towards optimising airliner operations for maximum efficiency this week when an Airbus A321 in airline service undertook what is claimed to be the most accurate curved approach procedure in the world.
The successful demonstration is the first of 10 planned flights this summer that will pave the way for the procedure to be published for general use by appropriately equipped aircraft and qualified crews in late August.
Under the European Commission's Mint project, the aircraft of Swedish leisure carrier Novair flew an optimised approach, avoiding ground communities, using not only 0.3nm (0.5km) required navigation performance, but also highly accurate wind information uplinked to the aircraft.
Lars Lindberg, chief executive of Avtech which provides project management and data analysis for Mint, says: "This is the best that we can do. Once we get new engines or new wings then we will do better. But for now this is the best that can be done."
Mint is designed to minimise carbon dioxide emissions in the terminal area, and the Novair flights are also aimed at minimising noise on the ground. Simulations show that the flights will save between 160kg (350lb) and 360kg of fuel per flight depending on the exact procedure flown.
The savings are achieved partly due to flying shorter tracks between the final approach point and the runway, and partly by avoiding power-setting adjustments to achieve the correct vertical profile.
The aircraft are equipped with the Thales/General Electric Release 1A flight management system, which in practice gives a track-keeping accuracy to within the wingspan of the aircraft itself, but is also able to store wind-data modelled by the UK Met Office from real-time wind measurements generated by other aircraft.
The result is that the aircraft flies a vertical trajectory that optimises its speed to avoid wasting excess energy or having to power-up to combat unexpected winds.
A complementary project, Cassis II, which like Mint is part of the Atlantic Interoperability Initiative to Reduce Emissions (Aire), will integrate the procedures into the air traffic control process so that aircraft will be able to negotiate and hit required arrival times, ensuring that the Mint benefits are not lost by manoeuvring in the terminal area.
Both projects in turn contribute to the aim of the European SESAR programme's aim of reducing CO2 emissions by 10% through more efficient operations.
Source: Flight International
