By mid-2014, pilots flying for at least one U.S. carrier could be able to save passengers time and their employer money with the push of a touchscreen and a verbal request to air traffic control during the cruise portion of a flight.

The capabilities are part of the NASA Langley Research Center's Traffic Aware Planner (TAP), an application that runs on electronic flight bags (EFB) in the cockpit. NASA flight-tested the system for the first time on an Advanced Aerospace Solutions Piaggio P.180 avionics testbed for two weeks in November, generating input from a consultant pilot and eight airline pilots who evaluated the application.

Preliminary results of the flight test were positive, giving a boost to agreements in the works for airline deployment. David Wing, Traffic Aware Strategic Aircrew Requests (Tasar) principal investigator with NASA's Langley Research Center, says Virgin America is interested in using the software, as is a mainline carrier, assuming the application can be ported over to the iPad.

Paul Harrison, flight technical manager for Virgin America and one of the volunteer pilots to fly in the Piaggio, says TAP could be one of the first applications to run on newly installed class 3 EFBs in the airline's 53 Airbus A319 and A320 aircraft next year, albeit initially without the automatic dependent surveillance broadcast (ADS-B) “in” traffic feature. “Our draw to it is for fuel savings,” says Harrison. “We do a lot of transcontinental flights, and the longer the flight, the more the savings.”

Along with ADS-B “in,” TAP uses broadband input for wind, airspace and weather information to help pilots optimize horizontal and vertical routing based on benefits to fuel burn, time en route, or a combination of the two. Behind the application is more than a decade of NASA research into self-separation, and more recently, a push from the Office of Management and Budget to develop tools that drive interest in voluntary equipage for ADS-B, says Wing.

Powering the application is a pattern-based genetic algorithm augmented by pilot-selected route optimization criteria that computes 500-800 trajectory alternatives waypoints every minute. Pilots can also use a manual mode to check for fuel or time savings at alternate altitudes or routing, with a maximum of two off-route waypoints, a number selected to limit air traffic controllers' workload.

TAP uses ADS-B data to determine if there are traffic conflicts with potential re-routes, a check that increases the likelihood that controllers might approve the request. The Piaggio is equipped with an ACSS TCAS 3000 ADS-B unit and Inmarsat broadband, which is used to bring in wind values and information about special use airspace and weather disruptions. The system is meant to be used above 10,000 ft. so as not to interfere with high-workload portions of a flight.

“It's a non-safety-critical app,” says NASA's Wing. “We're not changing roles of pilots and controllers. Pilots can already ask for a trajectory change. Controllers assess the request for safety, and approve or deny it.”

Wing says pilots on most of the 2.5-hr. test flights were approved for one or more route changes based on TAP guidance. Pilots used one of three routes for the test flight, each with differing air traffic control or airspace complexities. Wing says the flight test was not meant to directly measure fuel and time savings, given that routes were “round-robin” and software did not include a performance model for the Piaggio. Rather, the test was meant to determine how TAP performed with on-board and external information, to observe how the pilots interacted with the system and to generate change requests to air traffic control. “In my view, we accomplished this objective,” says Wing.

An earlier study conducted by NASA subcontractor Engility Corp. determined that network carriers could save as much as 4.2 min. per flight by optimizing for time, or as much as 575 lb. of Jet A by optimizing on fuel burn. For a low-cost carrier, the savings are somewhat smaller—a maximum of 2.9 min. or 406 lb. of fuel saved, respectively. The numbers appear relatively small in isolation, but could be significant if aggregated across a carrier's fleet. The analysis considered 510 flights between July 11-20, 2012, flying between 12 U.S. city-pairs.

Engility also developed the TAP software and conducted the flight trials with its partner, Advanced Aerospace, the owner of the Piaggio. NASA also contracted with Rockwell Collins to assess implementation requirements in terms of certification approval for the application (their conclusion: “low certification approval threshold”) as well as to conduct human-in-the-loop simulations with 12 airline pilots last summer. Those simulations, using a Boeing 777-200LR simulator at the University of Iowa's Operator Performance Laboratory, found that TAP has a “negligible effect on pilot workload” and that situational awareness was not degraded.