SAN DIEGO, 2 June 2009. The world's aviation authorities are looking into ways of employing precise aircraft navigation avionics to save fuel, reduce engine emissions, and cut aircraft noise by enabling high-performance passenger aircraft not only to use navigation and guidance technology to fly straight paths between airports, but also to fly relatively simple landing patterns upon arrival.
These new passenger jet takeoff, en-route, and terminal procedures are called RNP -- short for required navigation performance -- where aircraft essentially fly straight paths from their departure airports to the points at which they initiate their final approaches to their destination airports.
For the aircraft able to fly under RNP rules, this could mean no longer adhering to complex approach and landing patterns the require aircraft to descend, accelerate, and descend again to stay on established instrument landing approach patterns.
The potential savings in fuel, aircraft emissions, flight durations, and aircraft noise are immense, said Steve Fulton, chief technical officer of Naverus Inc. in Kent, Wash., in a presentation at the Avionics USA conference in San Diego, sponsored by the PennWell Aerospace and Defense Media Group.
Simply making these small adjustments to flight paths and landing procedures could save 4.5 to 10 billion gallons of jet fuel worldwide every year, Fulton says.
"Talking about deployments in these terminal areas to minimize fuel burn and maximize efficiency, we could reduce emissions," Fulton says. "For every one pound of fuel saved reduces three pounds of CO2 in the atmosphere."
Not every aircraft flying today is able to follow RNP procedures -- and some aircraft types probably would not be cost-effective to retrofit with the necessary avionics technology, Fulton explains.
To follow RNP procedures, aircraft need technology to fix its position precisely. This usually involves Global Positioning System (GPS) equipment. Then the aircraft needs precise lateral control, a way to display the aircraft's precise flight path, and path-following capability.
This normally requires glass cockpits with multifunction flat panel displays. Traditional mechanical gauges are rarely up to the task. On the ground, air traffic controllers can use existing arrival management tools.
Airlines looking into RNP procedures today include Qantas in Australia, and Southwest Airlines in the United States. If Southwest were able to reduce flight times by one minute each, the airline could reduce emissions by about 156,000 tons a year, Fulton says.