Transponders at R4N

(Updated:  March 10, 2013)

The Mid-Atlantic Soaring Association encourages the installation and use of transponders in gliders.  M-ASA has a Letter of Agreement (LOA) with the Potomac Consolidated TRACON (PCT) for the use of glider and tow plane transponders in the mid-Atlantic region.  The agreement is extended to all participants of M-ASA sponsored glider events held at W73 and FDK.  The LOA summarizes the importance of transponders in the national airspace system:

The use of transponders enhances safety by assisting air traffic controllers in the issuance of traffic advisories and enabling detection by Traffic Alert and Collision Avoidance Systems (TCAS) and Portable Collision Avoidance Systems (PCAS).  Since significant commercial, general aviation, and glider activity occurs in the vicinity of the Frederick Municipal Airport, the use of transponders by all aircraft operating in this area is highly recommended.  The use of pre-assigned transponder codes simplifys the process of pilots obtaining a discrete code, reduces controller workload, and allows FAA automation systems to present additional data to air traffic controllers.

The LOA stipulates the use of specific Mode 3/A codes at Fairfield as follows:

Gliders:  1230

Tow Planes:  0130

The PCT LOA takes precedence over the nationally assigned glider transponder code, 1202.  The codes are also recognized by controllers in adjacent ATC enroute centers and approach controls.  At the Potomac TRACON the automation software displays gliders with transponders as "GLDR" and tow planes as "TOW".  An indication of "TOW" serves as a flag to controllers that many more gliders without transponders may be airborne in airspace shared by powered traffic.  In general, transponders in the contest area can be detected by TRACON secondary radars above approximately 2000 feet MSL. 

During a P-40 TFR, gliders will squawk 1230.  Tow planes may be assigned a discrete transponder code by ATC.