Standard Operating Procedures and Letters of Agreement

Transponder Procedures

Date	Code	Version	Contact
2006-07-11	SOP-004	1.10	Facility Advisory Board (FAB)

1. PURPOSE:

This Standard Operating Procedure (SOP) provides a plan for the assignment of radar transponder beacon codes within the ZOA ARTCC.

2. ROLES AND RESPONSIBILITIES:

This SOP shall be maintained, revised, updated or cancelled by the Facility Advisory Board, and shall be effective unless there is a conflict with the VATUSA/VATSIM policies in which case they shall supercede these procedures.

3. DISTRIBUTION:

This SOP is to be read and used by all ZOA controllers.

4. BACKGROUND:

Unique beacon codes are are assigned to aircraft to aid in establishing radar identity. Duplicate code assignments will be 'flagged' by the new Advanced Simulated Radar Client (ASRC). To prevent assignment of duplicate codes within the ARTCC, a beacon allocation plan is required. The code assignment plan set forth in this SOP comply with the VATUSA National Beacon Code Allocation Plan.

5. TRANSPONDER PROCEDURES:

Transponder Operation.
1. It is expected that pilots will follow standard procedures for transponder operation as outlined in the AIM (section 4-1-19). DEL/GND/TWR shall not be responsible to insure pilot compliance with these procedures. ATC should assume pilots are familiar with the procedures and allow pilots adequate time to implement them. However, DEL/GND/TWR, may issue transponder instructions to aircraft on the ground to meet operational needs.
2. During events designated as "major events" by the ARTCC Event Coordinator, or at the request of overlying radar facilities (APP/CTR), DEL/GND/TWR should increase pilot discipline to place transponders in standby mode in accordance with AIM 4-1-19, to reduce clutter of symbology for grounded aircraft on radar displays.
Code Assignment Procedures.
1. Discreet beacon codes will be assigned to aircraft under the following situations:
  - IFR departures, as part of the departure clearance.
  - IFR "pop-ups", as part of establishing radar identity.
  - VFR departures within Class B and Class C airspace, as part of the departure clearance.
  - VFR departures requesting flight following that have been coordinated and accepted by the overlying radar facility, as part of the departure clearance.
  - IFR arrivals and transits arriving from uncontrolled (unmanned) airspace, as part of establishing radar identity.
  - VFR arrivals and transits through Class B and Class C airspace, as part of establishing radar identity.
  - VFR aircraft inflight requesting flight following, as part of establishing radar identity.
  - Aircraft squawking duplicate codes.
2. All aircraft that are assigned beacon codes within ZOA airspace in accordance with section (i) above, shall be assigned a code utilizing the automatic code assignment feature of ASRC/VRC. Squawk block assignments will be provided in the vZOA Position Operations File (POF). "Discreet" VFR codes (1201, 1202, etc.) shall not be used.
3. ATC shall utilize the following special code assignment procedures:
  - 1200 shall be assigned to VFR aircraft not under flight following service.
  - 1277 shall be assigned to VFR aircraft on active Search and Rescue missions.
  - 4000 (military VFR/MARSA activity) should be issued to military aircraft conducting operations with military special use airspace or operating VFR.
  - 4001-4077 military IFR operations.
  - 7500 (Hijack) is not to be used by ATC or pilots per VATUSA Policy.
  - 7600-7677 (Radio Failure) should not be issued by ATC.
  - 7700-7776 (Emergency) may be issued by ATC or set by pilots with aircraft declaring emergencies.
  - 7777 (military interception) per SOP-005.