RNAV Reduces Separation and Raises Efficiency in the Gulf of Mexico
Thursday, February 14, 2013

(NOTE: This article was produced by FAA Communications, with participation from NATCA.)

Using Performance Based Navigation (PBN), NATCA and the FAA have reduced the lateral separation required between aircraft over the Gulf of Mexico, which promises to save system users fuel, time and money.

The new Area Navigation (RNAV) route structure over the Gulf went into effect last month and cut the lateral separation requirement in half, from 100 nautical miles to 50.

That allows controllers to guide more airplanes on parallel paths through the same amount of airspace and reduces the need to put planes in a single trail with miles between them, which can be a slow and cumbersome way to fly across the Gulf.

The FAA estimates the new route structures will reduce the nautical miles airlines fly over the Gulf by more than 1,800 every day, saving them more than four hours of flying time and 34,000 pounds of fuel. That translates into a daily cost savings of more than $30,000.

“The new route structure will increase the availability of routes and flight levels over the Gulf of Mexico and enable more aircraft to operate on time and using fuel-efficient routes and flight levels,” said Karen Chiodini, manager of the Oceanic and Offshore Operations Group in En Route and Oceanic Services Operations Support. “That, in turn, will reduce fuel burn and engine emissions.”

RNAV, a primary component of PBN procedures, enables aircraft to fly on any desired flight path within the coverage of ground- or space-based navigation aids, or within the capability of aircraft self-contained systems. RNAV procedures allow equipped aircraft to fly more direct and precise paths with reduced controller or pilot input.

"This success is the culmination of years of focused work by the FAA and our international and industry partners," said Heather Hemdal, director of Operations and Safety Support for En Route and Oceanic Services. "Our collaborative effort to bring Performance Based Navigation to the Gulf stands to improve operations for controllers and save airspace users millions of dollars."

Houston Center saw the advantages of the new structure immediately, said Mike McGhee, the support manager at Houston Center (ZHU), who helped develop and implement the new route structure.

On the morning after the changes were put in place, thunderstorms blocked paths through the west side of the airspace over the Gulf. Controllers had to bring all the planes through the airspace to the east.

Normally, condensing all the traffic into a smaller swath of airspace would lead to delays. But the new route structure gave the controllers more options, and they were able to move the aircraft across the Gulf without adversely impacting schedules, McGhee said.

Controllers are quickly adjusting to the new setup, said Dustin Newell, the NATCA representative for the Lake Charles area at ZHU and a member of the team that helped implement the new route structure.

He said the efficiency gains in the Ocean East sector have been impressive. Thanks to the reduced separation, controllers can now move traffic north and south along an airway that had previously been reserved for northbound aircraft.

“It’s made everything a lot better,” Newell said. “It’s made it more efficient for us to operate.”

That kind of flexibility helps controllers at both ZHU and Merida, the Mexican air traffic control facility that handles traffic in the Mexican airspace over the Gulf.

Officials from SENEAM, the FAA’s counterpart in Mexico, were involved with developing the new route structure from the start. The FAA also worked with representatives from the International Civil Aviation Organization and the International Air Transport Association to make sure everyone’s needs were addressed.

The FAA also drew on the experience of implementing reduced separation in the airspace off the East Coast, McGhee said, bringing in experts who had helped with that effort.

At ZHU, controllers created a separate flight strip bay for MYDIA, one of the busier fixes in the airspace. Controllers rely on strips to maintain separation in the non-radar portions of the Gulf, and separating some of them into another stack cuts down on the amount of information they have to scan to ensure there are no potential conflicts for a particular flight.
 
“Sometimes we get seven, eight or nine MYDIA strips printing out at once,” Newell said. “Now we can move them to the other bay. When you’re busy that makes a big difference. It’s made things more efficient and safer.”

Controllers are still getting comfortable with the transitions to certain fixes that bring flights back into radar coverage in Ocean West, Newell said. He expects that once controllers get comfortable with the new setup, they’ll see the same advantages they’ve found in Ocean East.

In the Ocean West sector, four new RNAV routes were created, and three of the five legacy routes were deleted. In total, the project created 10 new RNAV routes and deleted eight legacy routes, “increasing the number of route options available for everyone to use across the Gulf of Mexico,” McGhee said.

The new route structure is the latest in series of changes bringing advanced technology to ZHU to help controllers increase safety and efficiency, McGhee said.

ZHU implemented Automatic Dependent Surveillance-Broadcast over the Gulf in 2009, reached initial operating capability for En Route Automation Modernization last April, began extended ERAM operations in January 2013, and will complete their implementation of new Required Navigation Procedures for the Houston Metroplex in December 2013 as part of the Optimization of Airspace and Procedures in the Metroplex project.