INCREASING NAS CAPACITY

Collaborative air traffic management

New concepts to control and distance aircraft are being implemented. Cockpit-managed separation trials may portend future development for autonomous airspace control.


SafeRoute cockpit display of traffic for interval management and spacing, arrival and approach. ADS-B guidance display at top, speed to fly and distance to selected target to follow at bottom. CMD SPD was speed to fly for separation. DFF GS was not used.

A test of IM-S during departure and enroute merging was conducted at the MITRE Corp flightdeck and ATC research center. A flightdeck simulator similar to a Boeing 777 cockpit was used.

Displays of traffic information were installed for each crew member and an ADS-B guidance display was installed in the center of the console.

Crew members used a touchscreen to select a target aircraft. Once the FIM-S was armed and engaged, the interval management speed was presented relative to current displayed IAS with vertical reference lines offering lower and upper IM speeds.

The ADS-B guidance display presented IM speed, target aircraft-to-follow information and current spacing interval as in-trail time.

A total of 9 scenarios were flown from ATL (Atlanta Intl, GA). Actual routings and fixes were used but no attempt was made to emulate real world flights or traffic density. The then-available DAWGS 4 departure was used. The target aircraft-to-follow proceeded directly to DAWGS after crossing ZELAN while the following aircraft received clearance for flightdeck IM-S after ZALLE. It was determined that the added task for flightdeck interval management should not occur below 10,000 feet MSL for workload consideration.

Typically, the system was engaged and started providing spacing guidance around 13,000 to 14,000 feet. The target-to-follow aircraft was usually about 25 nm in front of the following aircraft with the goal that the following aircraft would smoothly merge with desired timed spacing when crossing DAWGS.

There were 2 scenarios with either a speed range problem wherein the IM-S commanded speed was outside of the aircraft's operational limit (to prompt a cockpit call to suspend) or a suspend and resume command from ATC.

Generally, crews found the flightdeck IM-S to be acceptable and operationally suited to the conditions simulated. Most crews agreed that this type of added task to be compatible with flightdeck duties in the departure enroute phase of flight. As with the approach and arrival field exercise, there was some confusion about speeds to fly at certain points – specifically regarding the speed to maintain after crossing DAWGS.

Conclusion

The master plan for the future of the NAS states that fully automated traffic conflict resolution is pushed to 2030 and beyond. Cockpit-managed separation as a routine method to separate and sequence has to wait until ADS-B is implemented in 2020. A lot more testing and validation will also be necessary.

One second updates for ATC vs today's slower radar picture as well as added tools to place real time information exactly when and where needed are all part of the mix. And re-categorization of wake separation standards is ongoing for specific locations to permit more traffic in the same volume of airspace.

The simulator and field exercise where crews actively provided separation in concert with ATC showed what is enticingly possible. This, and other interesting programs and upgrades, all hinge on the fact that highly accurate point navigation, surveillance updates every second vs 6 to 12 seconds with radar, and more and better real time information at the right place will permit more traffic in the same volume of airspace.

Added onboard equipment with additional crew training will be necessary in some cases. However, the reality of increased flight density certainly will make this a necessity in the future.

Bill Gunn is former compliance manager for the Texas Dept of Transportation, Av Division. He is an ATP, CFII and FAA Safety Team rep. Bill lectures nationally for a private aviation advocacy group and is an aviation compliance mediator.


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