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Dan Hamilton is the Article 114 Representative to the SBS.  

Background:  The Surveillance and Broadcast Services (SBS) program was created to manage a program that will enable the air traffic control (ATC) system to migrate from one that relies on radar technology to a system that uses precise location data from the global positioning satellite network. An enabler of this evolution is the Automatic Dependent Surveillance Broadcast (ADS-B) technology. With this technology, both controllers and pilots will see radar-like displays of highly accurate traffic data. The system will also provide pilots access to weather services, terrain maps, flight information services as well as traffic information for better situational awareness.    

Automatic Dependent Surveillance – Broadcast (ADS-B)   

Terminal Fusion 

Andrew Stachowiak is the NATCA Article 114 ADS-B Terminal Fusion Representative / SME.  

Background: The Fusion Focus Group continues to track and resolve facility reported issues with Fusion generated from the 155 terminal sites. These discrepancies are mitigated by experts from all of the software and hardware fields. Please report any issues to your OSF and our NATCA SBS group for assistance. It is critical that actual data is recorded for evaluation and proper resolution. 

No changes since last report. 

Radar Divestiture  

Andrew Stachowiak is the NATCA Article 114 Radar Divestiture Representative / SME. 

Background:  Over two years ago, the NATCA SBS team started a collaboration with the agency in efforts to optimize the NAS. The implementation of ADS-B as the preferred surveillance source for the Fusion Tracker, created the opportunity to modify our radar infrastructure. The SPA (Surveillance Portfolio Analysis) work group performed an extensive inventory analysis report for all of the radar sources in the FAA. The program’s mission is to capitalize on the benefits of new surveillance technologies by strategically reshaping our radar infrastructure to gain efficiencies and optimize services for air traffic control (ATC) operations today and into the future. This will be a long and completely transparent process involving data gathering, expert analysis, local facility coordination, and a safety panel for each proposed radar removal. In some situations, additional radar feeds could be added to enhance surveillance. As this program matures, activities and other information will be updated here.   

The Radar Divestiture website: 



Virtual 90-minute working sessions regarding the proposed HQZ site removal in the Dallas Fort Worth Tracon (D10) airspace have been accomplished weekly since March 3rd. Proposed #2 site removal, MCC, had its kickoff meeting April 13th and weekly working sessions have begun as well. Offline Air Traffic evaluations have begun at D10/Dallas Fort Worth Center (ZFW) and those efforts are being coordinated at Northern California Tracon (NCT).    

Track-Based Display Mode (TBDM) 

Andrew Stachowiak is the NATCA Article 114 TBDM Representative / SME.  

Background: Track Based Display Mode (TBDM) is a new display mode in ERAM. TBDM makes ADS-B the preferred sensor and provides controllers using ERAM with smoothed track positions rather than last-reported or extrapolated target positions Smoothed track positions are displayed in sync with the preferred radar sweep (4.6 or 12 secs); use of the smoothed track position maximizes display accuracy. Reports from 0 to 8 radars along with ADS-B can be fused to form a single aircraft track. TBDM provides no changes to target/track symbology and the display update rate remains the same. TBDM enables the use of ADS-B as the preferred surveillance source to support 3NM Separation no longer limited to 3NM separation based on distance from a radar sensor. ADS-B will backfill Radar Cones of Silence and airspace beyond the distance and site limitations of existing SRRs and LRRs. New SBS Validation capabilities support significant future expansion of 3NM validation and separation anywhere in EnRoute Airspace at or below FL230 with validated ADS-B targets to the 3 NM Terminal service volume validation threshold. The TBDM adaptation changes coming out of a successful key site operation (ZSE/ ZBW), determined that the adaptation changes would be (nearly) transparent to the Controller workforce. Therefore, based on that Key site testing information, AJV-P approved NAS-wide Notices permitting the use of ADS-B for 3NM separation when operating in TBDM. An ADS-B validation build deployed at ZSE and SBS completed coverage plots showing where validated ADS-B may be used for 3NM separation. ZSE may expand 3NM operations using ADS-B in accordance with N JO 7110.773 and N JO 7210.920. SBS validation capabilities support the expansion of 3NM separation in ZSE airspace (CTV-2018). L3Harris deployed a validation build to RCS15 (ZSE) which allows 3NM separation throughout overlapped ADS-B radio station coverage. ERAM adaptation changes required for expanded 3NM polygons are no longer a limitation based on distance from a radar sensor.  

Memphis Center (ZME) plans to enable TBDM on 7/15/2021 and the TBDM Briefing is scheduled 6/22/2021. ADS-B Coverage Maps were completed for ZME on 6/8/2021. 

Oakland Center (ZOA) coverage Maps have been updated with new ADS-B radios at Truckee Tahoe (400-1) and Lake Tahoe (400-2). Coverage maps were completed on 6/3/2021.  

Jacksonville Center (ZJX) enabled TBDM on 2/25/2021 and began using ADS-B 3NM separation on 3/25/2021. Facility will request a brief prior to expanding 3 NM (ADS-B Only) airspace. 

Seattle Center (ZSE) and Boston Center (ZBW) (TBDM Key Sites) 

ZBW is moving forward with expanding ADS-B 3NM operations beyond existing 3-mile airspace. ZBW received Director approval for the expansion on 6/7/2021. ZSE built Reduced Alert Conflict (RAC) Aircraft Alert Volumes, for ADS-B and is now developing display mapping. 

ZSE submitted a request for additional ADSB radio in the vicinity of Chelan, WA (S10). Radio requested to provide coverage to facilitate 3NM coverage in the North Cascades. 

Request will be considered for inclusion in JRC Future Segments/FID funding. 

ADS-B Avionics Issues 

Andrew Stachowiak is the NATCA Article 114 ADS-B avionics issues SME.  

Surface Surveillance 

Dan Hamilton, SBS Lead Rep 

Surface Surveillance encompasses ASDE-X and ASSC. Programs falling under this category include SMR Infrastructure SLEP (Service life extension program,) SMR SLEP, SMR Replacement, MLAT Divestiture, Baseline merge and any other program impacting our surface surveillance platforms. 


Outreach briefings for the MLAT divestiture viability study have been completed at DTW and MDW. Both facilities are willing to participate. The briefing with CVG will take place on 6/22. Those three sites will be the main facilities of focus for the study.  

Space Based ADS-B (ASEPS)  

Dan Hamilton, SBS Lead Rep. 

Background:  With the terrestrial ADS-B platform fully deployed, the focus has turned to areas where surveillance is more difficult to achieve. Space Based ADS-B (SBA) utilizes low orbiting satellites to track aircraft that are ADS-B 1090ES Equipped. SBA provides updates every second, much like FUSION in STARS. SBA provides all the data controllers currently see on all platforms. It is also possible to gain additional data such as selected altitude. The team has been working with Miami Center (ZMA) as they are the key site for operational evaluation in the Caribbean. As work in ZMA progresses, the team is also working with the ATOP team in the development of future concepts for SBA in the oceanic environment. Future concepts include work with New Youk Center (ZNY), Anchorage Center (ZAN) and Oakland Center (ZOA).  

No change since previous update.  

Interval Management   

Tom Zarick is the NATCA Article 114 Interval Management Representative 

Chris Aymond is the Interval Management SME for Terminal 

Background:   Interval Management, or IM, combines ground-based and flight-deck systems to provide precise inter-aircraft spacing between aircraft, providing air traffic with another tool to manage traffic flows. The objective of the IM application is to achieve and/or maintain an assigned spacing goal (ASG) between the IM aircraft and the ATC-designated aircraft by having the pilot follow speed commands generated by the flight deck avionics. The ASG is provided by the controller and may be given in time or distance.   

ADSB-In Retrofit Solution (AIRS) & CAS (CDTI Assisted Separation) 

Background:  AIRS and CAS are applications within the Interval Management domain that the Agency and American Airlines are engaged in an effort to promote the benefits and viability of ADSB-In.  

The deployment strategy for IM will consist of three phases. The first phase or Phase 1, (similar to the AIRS concept) will consist of a subset of the IM functionality which will be limited to the same runway operations. Phase 2 will introduce more complex IM operations utilizing more of the flight deck avionics that adds functionality for Dependent Staggered Approaches (DSA) and Dependent Converging and Crossing Runways (DCCR). Phase 3 will introduce advanced IM capabilities that will be deployed to only a handful of facilities due to its limited benefits.  

Updates and Upcoming Activities:  

  • A Mitre activity took place the week of June 14th at their Mclean campus with the goal of demonstrating the viability of a “simple IM” miles in trail operation.  The only method of coordinating for this demo was through the 4th line or voice communication.  The equipage rate used for the demo was 50%.  It was determined that more ground automation tools will be needed well in advance of the 50% equipped number. 
  • The SBS PO anticipates an FY23 funding cut that will impact the Phase 1 IM deployment.  While these cuts will not impact the AIRS trials at Albuquerque Center D10 and ZAB, it could delay the additional ground automation tools being developed to support expansion of AIRS into other facilities. 
  • American Airlines equipage for the month is unknown at the time of this update due to a last-minute meeting cancellation. The last update was 41 equipped with 9 undergoing the upgrade in May. 
  • Bi-weekly meetings with D10 and Albuquerque Center (ZAB) continue in preparation for the upcoming CAS and I-IM trials. 

WAM (Wide Area Multilateration)  

Andrew Stachowiak is the NATCA Article 114 Terminal Representative / SME.  

Background: WAM is a surveillance source that backs up ADS-B. MLAT constellation over wide area = WAM. 

Multilateration (MLAT) is:  

  • Technology that utilizes multiple low-maintenance, ground radio stations to determine aircraft position and provide surveillance coverage within a defined region.  
  • Cooperative system which requires aircraft transponder signals – ADS-B link v2 and UAT aircraft do not require interrogations. 
  • Enhances the coverage area of a traditional radar or acts as a stand-alone surveillance system. 
  • Surveillance requirements analysis determines the number and positioning of each radio necessary to achieve required coverage. 
  • The process of determining location in two (or three) dimensions based on the time difference between the transponder’s signal reception at multiple sensors. 

Key concepts of MLAT processing include the following:  

Transponder signal is received at multiple radio stations, Signal is time-stamped at each station, Time stamped signal is sent from each station to a target processor, The target processor calculates the Time Difference of Arrival (TDOA) between all sensor pairs detecting the target, the calculated TDOAs are used to determine the target position, and the target position information is output by the target processor to track processing functions. 

WAM sites  

Colorado (ERAM), Juneau (MEARTS), Charlotte (CLT), Southern California Tracon (SCT) (STARS) will conduct an In-Service Acceptance Test (ISAT) flight planned for the week of April 26 to establish their new CTV that supports a WAM 360 surveillance solution. 

LA WAM Expansion  

Tuning flights completed 3/4/2020. WAM ISAT flights completed 5/4/21. There are target acquisition issues with ATCRBS transponder in the southeast quadrant. Currently there is no solution readily available. Regression testing of some form will be in order after a solution is deployed. FAA flight Inspection is currently scheduled to begin 8/31/21. IOC is TBD and dependent on the S6.00R9 STARS software release 9/16/21. 

Working to evaluate and determine SBA service volumes in all ATOP Procedural airspace. 

National Airspace System (NAS) Voice over IP Communication Enterprise (VoICE)  

Jon Shedden is the Article 114 Representative to the VoICE project.   

Background:  The National Airspace System (NAS) Voice over IP Communication Enterprise (VoICE) program will encompass what was the NVS program. This will include acquisitions to replace our aging voice switches, as well as Radio Control Equipment (RCE). The FAA has begun the installation of multiple small Commercial Off the Shelf (COTS) voice systems. The FAA intends to use these systems to revise and update requirements for the Voice Communications System Specification to better align with existing industry standards. This effort, named the COTS Hands-On Requirements Up-leveling Sessions (CHORUS), is tasked with evaluating existing voice system requirements in conjunction with these COTS systems. Mr. Shedden and the CHORUS team traveled to the William J Hughes Technical Center the week of 6/7 For the CHORUS kickoff. The team executed and discussed 4 scenarios.  The CHORUS team will travel to the tech center the week of 6/21 to continue the scenario execution.  

Alaska Flight Service was scheduled to have their aging voice switch replaced with NVS. Now that the NVS contract has ended, work has begun to find a suitable replacement. The FAA is exploring all options to replace Alaska’s voice switch. 

Next Generation Air-Ground Communication (NEXCOM)  

NEXCOM continues the deployment of new CM300/350 V2 radios to terminal facilities across the country. The NEXCOM program office is working on the Emergency Transceiver Replacement to replace aging tunable transceivers at Denver (DEN), Honolulu (HNL), Potomac Tracon (PCT), Phoenix (PHX), Southern California Tracon (SCT), and Salt Lake City (SLC). Work continues in 2nd Level Engineering to develop a suitable replacement. The FAA is also looking to replace 2000 of the grab-and-go style emergency transceivers (e.g., PET-2000). The contract has been awarded to General Dynamics. The replacement will be on the GD URC-300E platform. The post award conference occurred the week of April 12th. Discussions on training development have begun. Key site is currently planned for Jacksonville Tower/TRACON (JAX) in FY22-Q4. Training development for the ETR continues with AJI. 

NAS Voice Recorder Program (NVRP)  

NVRP is the replacement for existing NAS voice recorders (DALR, DALR2, DVRS, DVR2). NICE Ltd. was officially awarded the NVR contract to replace the legacy voice recorders. Key site activities are ongoing. Air traffic has begun reviewing the vendor provided training for suitability.   

Tone Mitigation National Workgroup 

The Tone Mitigation National Workgroup is working on ways to eliminate/reduce the continuing tone/noise event in the NAS, as well as provide better protection to controllers through new headsets. Testing of new headset bases has occurred at PCT and Houston Tracon (I90). Further testing was scheduled at Miami Center (ZMA) and New York Tracon (N90) but has been delayed. Discussions are ongoing regarding how to resume headset testing during the pandemic. 

The FAA is in the process of purchasing 1000 headset splitters for use in terminal facilities with only 2-jack positions. This is related to CAR-2012-001 and will allow controllers to perform position relief briefings during OJT. Work continues updating the deployment spreadsheet to capture Section 804 facilities as well as facilities that were expected to get NVS. A survey was sent to the field to get a more accurate response to the number of splitters needed at each facility. A minor issue with the splitters was discovered by Portland TRACON (P80). The program office is working with the manufacturer to resolve the issue, prior to widespread deployment. 

The FAA is in the early stages of a technical refresh of the Small Tower Voice Switch (STVS). There are approximately 130 STVSs across the NAS. The FAA and NATCA are working collaboratively on the controller’s human machine interface for the refreshed panels. Key site is currently planned for McClellan-Palomar Airport (CRQ). Key site surveys are scheduled to occur in the week of July 12th.  Pre-production hardware has been delivered. Evaluations are currently being planned. Discussions with the program office regarding training are ongoing. The program is still on schedule for key site in FY22. 

The Voice Switch and Control System (VSCS) Training and Backup Switch (VTABS) is scheduled for replacement of the PECO Power Subsystem at all ARTCCs. A national SRM panel was held remotely on April 7th. The replacement will result in VTABS being unavailable for up to 3 days at each ARTCC. A significant amount of prep work will be done at each ARTCC to ensure the availability of VSCS during the installation. This project is currently on hold due to the pandemic.  

Jon Shedden 

NATCA Voice Comm Representative 



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