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Fact Sheet – En Route Automation Modernization (ERAM)

For Immediate Release

April 29, 2015
Contact: Tammy Jones
Phone: (202) 267-3883, Email:

The computer system the FAA uses at its high altitude en-route centers is considered the backbone of the nation’s airspace system. The system processes flight and surveillance data, provides communications and generates display data to air traffic controllers.

Several years ago, the FAA began replacing the legacy system known as the Host with a new, NextGen-enabling system known as En Route Automation, or ERAM.

ERAM provides core functionality for air traffic controllers, and the FAA designed it to support satellite-based systems such as Automatic Dependent Surveillance-Broadcast and data communication technologies. Working together, all of these systems will improve efficiency and enhance safety. 

Lockheed Martin developed the ERAM system for the FAA. The system is now operational at 20 Air Route Traffic Control Centers – also known as en-route centers – throughout the United States and at the FAA Academy in Oklahoma City, Oklahoma.

Other FAA air traffic facilities, including Terminal Radar Approach Control facilities and towers, are connected to en-route centers via ERAM. The system also connects with the FAA’s Command Center in Warrenton, Va., automated flight service stations, and other agencies, including the Department of Homeland Security, the Department of Defense and U.S. Customs and Border Protection.

ERAM increases capacity and improves efficiency in the nation’s skies. It enables en- route controllers at each center to track 1,900 aircraft at a time, while the legacy system could track up to 1,100 aircraft). Coverage extends beyond facility boundaries, enabling controllers to handle additional traffic more efficiently.

The system allows controllers to share and coordinate information seamlessly between centers, enabling the use of three-mile (rather than five-mile) separation.  ERAM improves flight plan processing and enables automatic transitions between sectors and centers, even when planes divert from their planned course. This improves operational efficiency during bad weather and congestion.

ERAM provides many additional benefits over the Host, the 40-year-old legacy system it is replaced:

  • It is a long-term, cost-effective measure.  The ERAM program replaces four legacy systems used in today’s air traffic control centers, reducing the hardware operating and support costs, as well as the total number of software code lines and the cost of software maintenance.
  • It provides more accurate tracking. The ERAM tracking function processes target reports from multiple radars, replacing the single radar tracker in the legacy system. This provides more reliable tracking in areas of partial radar coverage.  An independent study the MITRE Corporation performed concluded that the ERAM tracker was more accurate than the legacy system in all cases. The ERAM tracker also processes Automatic Dependent Surveillance-Broadcast (ADS-B) data that is part of NextGen.
  • It improves flight plan processing. The ERAM system significantly improves on flight plan processing. ERAM creates a 4-dimensional trajectory (3D plus time) of every flight from take-off to landing. The system uses this information to improve a controller’s situational awareness in his or her airspace as well as the surrounding airspace, enabling better decision-making and safer, more efficient routing of aircraft along their flight path. The system can now warn controllers when aircraft are unexpectedly entering their airspace, and provides improved capabilities for handling military aircraft to ensure their training exercises and military missions do not interfere with civilian flights. Improvements in the automation function that transfers control of a flight from one controller to the next allow ERAM to control flights on fuel-efficient, direct routes in the sky.
  • It provides advanced controller tools. ERAM takes advantage of the improved tracking accuracy and flight plan processing to create more accurate controller tools. Like today’s system, ERAM detects conflicts between two aircraft, but is more accurate, reducing the number of missed alerts false conflicts. It also adds new capabilities to operate with variable separation standards, allowing the controller to separate aircraft in the most efficient manner possible, increasing airspace capacity.  Work is underway to add new controller tools that allow more efficient airborne routing around convective weather, reducing fuel burn and improving airline schedule predictability. Other functions will allow airlines to take advantage of their on-board equipment (RNP/RNAV) to fly fuel-efficient routes, improve airspace safety, and reduce noise and emissions to protect the environment. 

The En Route Information Display System provides real-time aeronautical information, enabling more efficient data management.

A fully redundant backup channel precludes the need to restrict operations in the event of a primary failure. The backup channel also provides safety alerts and weather information not available on today’s backup system.

ERAM has increased flexibility in routing around congestion, bad weather and other airspace restrictions. Automatic flight coordination increases efficiency and capacity.


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