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3. SOP_004 Transponder Procedures

Transponder Procedures

 

SOP-004

ZSE Senior Staff

Version 2

 

Amended 2018-10-25, changes noted in bold font.

 

1. PURPOSE:

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

2. ROLES AND RESPONSIBILITIES:

This SOP shall be maintained, revised, updated, or canceled by the ZSE Senior Staff, and shall be effective unless there is a conflict with the VATUSA/VATSIM policies in which case they shall supersede these procedures.

3. DISTRIBUTION:

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

4. BACKGROUND:

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

5. TRANSPONDER PROCEDURES:

a. Transponder Operation

i. 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 ensure 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. 

ii. During events designated as "major events" by the ZSE 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 the clutter of symbology for grounded aircraft on radar displays. 

b. Code Assignment Procedures.

i. Discrete 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. 

ii.  All aircraft that are assigned beacon codes within ZSE 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 ZSE Position Operations File (POF). "Discreet" VFR codes (1201, 1202, etc.) shall not be used. 

iii.  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. 

iv.  Listed Approved Transponder Beacon Codes: 

Center

Seattle Center (SEA_CTR): 6601-6677

Seattle HIGH Center (SEA_H_CTR): 6601-6677

Seattle LOW Center (SEA_L_CTR): 4701-4777  

Seattle North Center (SEA_N_CTR or SEA_NE_CTR): 6601-6677

Seattle South Center (SEA_S_CTR or SEA_SW_CTR): 4701-4777

Seattle A Sector (SEA_A_CTR): 6601-6637

Seattle B Sector (SEA_B_CTR): 6640-6677

Seattle C Sector (SEA_C_CTR): 4740-4777

Seattle D Sector (SEA_D_CTR): 4701-4737

Seattle F Sector (SEA_F_CTR): 3560-3577

Seattle G Sector (SEA_G_CTR): 3501-3547

Seattle J Sector (SEA_J_CTR): 3560-3577

Seattle K Sector (SEA_K_CTR): 3501-3547

Seattle M Sector (SEA_M_CTR): 4601-4643

Seattle D HIGH Sector (SEA_HD_CTR): 6640-6677

Seattle A HIGH Sector (SEA_HA_CTR): 4601-4637

Seattle B HIGH Sector (SEA_HB_CTR): 4740-4777

Seattle C HIGH Sector (SEA_HC_CTR): 6601-6637

Seattle A LOW Sector (SEA_LA_CTR): 4601-4637

Seattle B LOW Sector (SEA_LB_CTR): 4740-4777

Seattle C LOW Sector (SEA_LC_CTR): 4640-4677

Seattle D LOW Sector (SEA_LD_CTR): 4701-4737

Seattle Area Facilities

Seattle Approach/Departure: 1501-1577

Seattle-Tacoma International Airport: 1501-1577

All other fields under Seattle Approach Airspace: 1550-1577

Portland Area Facilities

Portland Approach/Departure: 1601-1677

Portland International Airport: 1601-1677

Portland-Troutdale Airport: 1650-1677

Portland-Hillsboro Airport: 1650-1677

Other Approach Facilities

Spokane Approach and underlying fields: 3501-3547

Grant County Approach and underlying fields: 3560-3577

Chinook Approach - Pasco Sector and underlying fields: 4601-4643

Chinook Approach - Yakima Sector and underlying fields: 4601-4643

Cascade Approach - Eugene Sector and underlying fields: 4726-4762

Cascade Approach - Medford Sector and underlying fields: 4763-4777

Additional Beacon Codes

"Outlying" facilities not tied to a parent TRACON: 4701-4777

Reserved Use: 5101-5277