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Air Traffic Services Brief -- Traffic Information Services

Air Traffic Services Brief

Traffic Information Services

The issue

On April 8, 2005, without consultation from AOPA or other aviation organizations, the Federal Aviation Administration (FAA) issued a decision paper, Discontinuation of Mode S Traffic information Service (TIS) at Sites Where ASR-7/8 Radars Are Replaced by ASR-11. In the paper, the FAA claimed that the safety benefits of TIS did not warrant the cost to continue providing the services. It has identified 22 sites where an ASR 11 upgrade will eliminate TIS by 2012.

What is TIS?

Click for larger image
TIS data from a Garmin GRX 330
transponder displayed on a GNS 430.

TIS is a first-generation traffic system that supports cockpit depiction of traffic, using a TIS service available from 107 Mode S terminal radars. These radars have a "software upgrade" in them that recognizes a Mode S TIS transponder and uplinks proximate aircraft traffic.

A TIS-capable Mode S transponder (Garmin GTX 330 or Honeywell Bendix KT73) is needed to receive the information, and a display is needed to depict the traffic graphically. The display is usually a multifunction display or a multi-purpose GPS. AOPA believes that a significant number of aircraft are equipped with TIS capabilities, between 10,000 and 12,000.

The importance to our members

AOPA members indicate that traffic data in the cockpit is a valuable datalink service that enhances safety. More than 10,000 pilots have purchased TIS, and it is currently the most affordable system available to general aviation. AOPA is concerned about the FAA's unilateral decision to cancel these services without notification. Members have invested in the TIS capability, and it appears that the FAA has now backed away from a commitment to provide TIS. Avionics manufacturers continue to market and sell TIS-capable equipment, and a 25-percent reduction in TIS services reduces the effectiveness of the member investment.


In the mid-1990s, the FAA developed a datalink where Mode S radar systems transmit traffic data to Mode S transponders. The system was later dubbed TIS, and by 2002 the system was active on many ASR 7 and ASR 8 Mode S radar sites. As part of the FAA's radar system upgrade, the FAA ordered ASR 11s to replace older ASR 7/8. Because the FAA failed to require TIS functionality, these new systems do not have the TIS capability. The FAA originally proposed to move these "old" radars to less busy terminal airspace areas, meaning no TIS services would be lost. However, the FAA has now abandoned this plan.

It is AOPA's understanding that the manufacturer of the ASR 11 can provide the upgrade to all ASR 11s for $49 million.

AOPA's position

AOPA is disappointed with the FAA's decision to cancel TIS services without coordination with the aviation community. Safety improves when graphical depiction of traffic is available in the cockpit. The FAA's goals to reduce general aviation safety are partly on its strategy to provide more information into the cockpit. The FAA needs to provide graphical traffic services as part of its services to pilots and should advise pilots as to its strategy.

TIS Cancellation Schedule Segment 1

Location Date
Bangor, Maine Canceled November 2004
Springfield, Missouri Canceled April 2005
Billings, Montana Canceled May 2006
Ft. Smith, Arkansas Removed from cancellation schedule. Currently active.
Santa Barbara, California Canceled November 2006
Pensacola, Florida Canceled May 2007
Abilene, Texas Canceled September 2007
Fargo, North Dakota Canceled July 2007
Macon, Georgia Canceled November 2007
Little Rock, Arkansas Imminent as of April 2008
Corpus Christi, Texas Imminent as of April 2008
Midland, Texas Canceled March 2008

TIS Cancellation Schedule Segment 2

Location Date
Roanoke, Virginia TBD
Tallahassee, Florida TBD
Bristol/ Tri-Cities, Tennessee TBD
Duluth, Minnesota TBD
Jackson, Mississippi TBD
Great Falls, Montana TBD
Evansville, Indiana TBD
Lake Charles, Louisiana TBD
Wilmington (New Hanover), North Carolina TBD
Bismarck, North Dakota TBD

Note: The revised schedule indicates that the FAA has not set dates for the decommissioning of the last 10 locations, but the FAA indicates the services will end before 2012.

Web site links

Updated Monday, June 2, 2008 2:53 PM