ATPA: A Helpful Tool for Controllers When Monitoring Separation
Thursday, July 12, 2012

EDITOR’S NOTE: This is the next in a series; we are spotlighting each of the safety and technology programs in which NATCA is participating collaboratively with the FAA.

PROGRAM NAME: Automated Terminal Proximity Alert

ACRONYM: ATPA

NATCA ATPA NATIONAL REPRESENTATIVE: Mickey Vitti (New York TRACON, N90); mvitti@natca.net

NATCA PROJECT REPRESENTATIVES (CHI Work Group): The most recent CHI evaluation took place on May 16-17, 2012 at Lockheed Martin in Eagan, Minn. The CHI team consisted of: Nancy Qasem (Southern California TRACON), Ed Rivas (DFW TRACON), Vanessa Shinners (Miami Tower/TRACON) and Michael Wollert (Northern California TRACON).

PREVIOUS CHI WORK GROUP MEMBERS: Mark Nordeen (Minneapolis TRACON), Christa Proffitt (Cincinnati Tower/TRACON), Joseph Salerno (Charlotte Tower/TRACON) and Chad Sneve (A80).

WHAT IT DOES: ATPA is a tool designed to reduce compression errors on the Final Approach Course (FAC). The manual version, Terminal Proximity Alert (TPA) is being used operationally at many FAA facilities nationwide and is a helpful tool for controllers to use when monitoring separation between aircraft.  

Enhanced TPA (ETPA) and ATPA are currently being deployed at all Common ARTS (CARTS) facilities with color displays. Both tools work in concert with the manual TPA version, and are used operationally by controllers to aid in maintaining separation or identifying diminishing separation between aircraft.  

HOW IT WORKS: ETPA and ATPA are advisory in nature and use is voluntary for controllers. They do not change the way Certified Professional Controllers (CPCs) separate aircraft. The tools do not replace any existing automation or air traffic procedures (existing procedures in FAA JO 7110.65 and current automation are the primary means to separate aircraft). In addition, the ATPA functionality is also planned for deployment in STARS at a future date.

For aircraft on the FAC, ATPA displays a graphical notification when a potential loss of separation is detected. Unlike the manual TPA, this notification is provided automatically. ATPA also automatically depicts separation minima in the center of the ATPA notification cone. This feature aids controllers in more accurately ensuring separation on the FAC.  

It is expected that higher levels of accuracy and efficiency can be gained with the help of this tool. Additionally, but separate from ATPA, the current distance between two IFR aircraft, that are both located within an enabled ATPA FAC region, can be displayed in line three of the Full Data Block (FDB) of the trailing aircraft (below).



THE TASKS PERFORMED BY ATPA:
1. Determine the separation minima between associated IFR aircraft.
2. Automatically display an ATPA cone when a loss of “in trail” separation is predicted to occur or has occurred.
3. Ensure the size of a TPA Cone currently displayed for a track that is entering an enabled ATPA FAC region is not less than the required separation minima.

ATPA will display three types of cones. The size of all ATPA cones is equal to the minimum separation for the track pair at the threshold. If the trailing track is “small” and the lead track is “large,” the size of the ATPA cone is four nautical miles. All ATPA cones originate from the trailing track and orient towards the lead track.

The type and purpose of each ATPA notification and its associated color are described in this chart HERE.

FACILITIES USING ATPA IN PHASE 1: M98/MSP, T75/STL, NCT/SFO, C90/ORD and all six areas (and their associated towers) at SCT.

FACILITIES COMING ONLINE IN THE NEAR FUTURE: A80/ATL and D01/DEN.

FORMER ATPA REP DAN ELLENBERGER’S PERSPECTIVE ON THE PROGRAM: “I have served as the National ATPA Article 48 Representative since January 2011. Initially, the program suffered from what I would term as a lack of leadership and direction. After several challenging months, along with some personnel changes by the Agency, we were able to collaboratively establish specific work group guidelines, as well as clearly define a course of action; all of which is contained in a scoping document that was developed and signed by both parties.

“Collaboration, specifically by the parties involved in the ATPA program over the last year, has been an integral part of the successes that we have experienced. My Co-Lead, Steve Batchelder, as well as each additional work group member and representatives from Lockheed Martin and Raytheon, have been instrumental in identifying, supporting, implementing and working as “equal” partners to make this program a success.”

RECENT DEVELOPMENTS: The work group, as well as representatives from Lockheed Martin (CARTS), Raytheon (STARS) and the program’s support contractor, Human Solutions Inc. (HIS), meet on a regular basis. The most recent meeting took place the week of June 18, 2012 at Chicago TRACON (C90).  

“We reviewed preliminary results of the ATPA Phase 2, Computer Human Interface (CHI), evaluation conducted in May and reached consensus on all items evaluated by the test team,” Ellenberger said. “The development of the Phase 2 requirements has been underway for several months and will be completed in the very near future. As a result, our discussions included the need to develop a strategic plan for the program’s continued development. We also reviewed and prioritized a list of proposed Phase 1 changes/improvements and discussed preliminary thoughts on a development plan for Phase 3 work. The intent of Phase 3 will be to incorporate wake turbulence criteria and possibly wind components.”