October 2, 2006

Jonas Dino
NASA Ames Research Center, Moffett Field, Calif.
Phone: (650) 604-5612 / 9000
E-mail: jdino@mail.arc.nasa.gov

RELEASE: 06_70AR

NASA HELPS AIRCRAFT GLIDE INTO A MORE EFFICIENT LANDING

NASA is saving jet fuel by helping aircraft achieve the ideal glide 
path as they approach a crowded airport for landing.

NASA Ames Research Center, Moffett Field, Calif., and The Boeing 
Company, Chicago, Ill., in partnership with the Federal Aviation 
Administration (FAA), Washington, United Airlines, Chicago, and the 
San Francisco International Airport (SFO), have completed trials to 
study the effectiveness of the Oceanic Tailored Arrivals (OTA) 
concept for aircraft landing at SFO. Currently, the ideal landing 
approach, an even continuous descent, often is interrupted with 
course changes and altitude level-offs. These deviations can result 
in increased fuel use, noise and environmental emissions. The study 
is investigating the customization of aircraft descent procedures 
using the latest in communications and aircraft navigation technology 
and NASA air traffic management algorithms to maintain the ideal 
approach.

"The goal of the Oceanic Tailored Arrivals initiative is to allow 
aircraft to descend in a manner that is both fuel efficient and 
environmentally friendly," said Rich Coppenbarger, lead investigator 
for the Oceanic Tailored Arrivals Initiative at NASA Ames. "We are 
prototyping automation tools and procedures to help controllers 
strategically anticipate and solve arrival problems well in advance, 
allowing for more ideal descent operations, especially during busy 
traffic periods where potential benefits are greatest." 

During the initial portion of the trials, researchers are working with 
controllers at the FAA's Oakland Air-Route Traffic Control Center and 
the Northern California Terminal Radar Approach Control to tailor the 
approach of a United Airlines Boeing 777 equipped with 
state-of-the-art avionics, approaching SFO en route from Hawaii.

At approximately 300 miles from the destination airport, a 
four-dimensional descent profile, customized for each aircraft and 
airspace conditions, is generated with help from the NASA 
Ames-developed En Route Descent Advisor (EDA). The ideal descent 
profile is then transmitted via high-speed data link to the aircraft. 
Once reviewed by the flight crew, the profile is loaded automatically 
into the aircraft's Flight Management System (FMS) where it is used 
to compute a complete trajectory prediction to the runway. The FMS 
uses this prediction to accurately guide and control the aircraft to 
landing with very few manual inputs required by the flight crew. 

Along with fuel savings, OTA approaches have the potential to 
significantly reduce noise and environmental impact at surrounding 
airports. Tailored Arrivals also may reduce workload by providing 
pilots and controllers with a common understanding of the intended 
arrival path and reducing the need for voice communications. Tailored 
Arrivals enable pilots to fly airplanes as they were designed to be 
flown, which helps reduce crew workload and errors, according to Rob 
Mead, Boeing Phantom Works lead engineer for advanced air traffic 
management air/ground communications. 

In addition to the SFO trials, Boeing has spearheaded trials in 
Australia and the Netherlands. 

"Early reaction from pilots and controllers to the OTA concept has 
been very encouraging," said Coppenbarger. "Initial fuel savings for 
a Boeing 777 have been estimated at 200 to 800 pounds per flight, in 
comparison with simulated operations representing congested traffic 
periods where continuous descent approaches are impeded," he added. 

Trials are expected to continue later this year after the initial data 
are compiled and analyzed.

The Oceanic Tailored Arrivals Initiative is funded through the NASA 
Airspace Systems Program at NASA Headquarters, Washington. The En 
Route Descent Advisor is a building block of the next-generation air 
transportation system that scientists at NASA Ames are helping 
define.

For more information about the NASA/Boeing Oceanic Tailored Arrivals 
Initiative, visit:



http://www.nasa.gov/centers/ames/research/2006/conops_ota.html



For more information about NASA's Aeronautics Research Mission 
Directorate, visit:



http://aeronautics.nasa.gov

	
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