Standard Operating Procedures and Letters of Agreement

Tower Control Procedures

Date	Code	Version	Contact
2009-10-21	SOP-003	1.02	Facility Advisory Board (FAB)

PURPOSE:

This Standard Operating Procedure (SOP) sets a standard and consistent practices for the operation of tower facilities.

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.

DISTRIBUTION:

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

BACKGROUND:

Most towers within a region of VATSIM airspace are unmanned. When a facility such as an Approach Control or Center Enroute Control overlies a field, that facility may be able to provide service for that field. This SOP sets forth a standard procedure for Clearance Delivery, Ground and Tower services to be provided, so that pilots can expect a consistent approach to airport operations.

AIRPORT CONTROL PROCEDURES:

Real world periods of operation.

For purposes of VATSIM ZOA, air traffic control facilities will not be required to conform to real world hours of operation. Since many online pilots do not have access to this information, and controllers may wish to operate towers at random hours, any tower with an associated Class D airspace may be opened regardless of the published real world hours of operation.
Restrictions on operations.
1. As the method of publication varies, and since many online pilots do not have access to this information, for purposes of VATSIM ZOA, no real world published restrictions, such as noise abatement procedures, aircraft class restrictions, or restrictions on type of operations will be applicable, unless they are specifically included in SOP_050 or the overlying sector SOP.
2. To insure orderly traffic flow, the controller operating the TWR may deny requests for training operations including touch and goes and practice instrument approaches to any aircraft. Controllers are encouraged to provide alternate training locations in the nearby area.
Tower airspace management.
1. Unless otherwise noted in SOP_050, The TWR position shall own airspace 5 miles in radius from the center of the field, from surface to 2500' above the field elevation. This shall apply to all airports charted as towered within Class B, C and D surface areas.
2. Approach controllers shall instruct aircraft to contact TWR prior to entering the towered owned airspace. The radar handoff feature shall not be used between approach control and TWR.
3. Certain towers will be given authority to use radar procedures to separate traffic; this authorization will be provided in SOP_050. At those towers where authority to use radar separation is not given in SOP_050, tower controllers will be responsible for providing traffic separation using non-radar or visual separation methods.
Class B & C tower positions - not manned.

For fields within the surface area of Class B or Class C airspace, when the TWR position is not manned, the overlying approach controller will assume tower management responsibility; SFO and OAK lie on the boundary of two approach control sectors, the Norcal approach SOPs specify which controller shall have responsibility for the operation of the tower. If workload does not permit providing these services, the controller may declare the tower "closed" (converting the airspace to Class E "uncontrolled"), but must insure that all aircraft in the airport area are made aware of the closure and are advised to switch to the advisory frequency.
Class D tower positions - not manned.

For fields within Class D airspace, DEP, APP, and CTR are not required to provide radar services; if the controller chooses not to, he should handle operations at these fields as uncontrolled Class E airports. However, radar controllers are encouraged to operate these towers. If the controller is going to operate the tower, he must insure that the service is uniform, such that all aircraft in the airport area are made aware that the tower is open.

For "closed" Class D Towers:
- VFR aircraft should be instructed to make traffic advisory announcements on the advisory frequency and given a frequency change instruction to do so.
- IFR departures should be given an IFR release and instructed to contact the appropriate radar facility once airborne.
- IFR arrivals should be given frequency change approval and told to "report canceling IFR this frequency" when they are separated from other traffic and established on the final approach course.
Non-movement areas.

As aircraft surface movement operations on VATSIM are monitored from the radar client, and therefore cannot be observed with high precision, ATC shall not be responsible for aircraft pushbacks. Thus ATC shall not clear or approve any pilot request for engine start, pushback, towing, or engine shutdown. Requests for engine starts or pushbacks should be conducted at pilots discretion only.
VFR flight during IMC.

ATC is not responsible to enforce the pilots adherence to FARs. Final judgement of WX conditions lies with the Pilot In Command. If a VFR pilot attempts to operate at the field during reported instrument meteorological conditions (IMC), ATC should:
- Advise that IMC conditions are currently being reported.
- Advise that a Special VFR clearance can and should be obtained (if locally permitted).
- Advise that VFR takeoff and landing clearances can not be issued.
Airport open with no radar service.

When a DEL, GND, or TWR position is operating with no radar facility providing approach/departure services (i.e. the overlying CTR, APP, and DEP are offline) the following special procedures and phraseology must be used (it should be noted that this situation is unique to VATSIM and no valid real world model exists):
1. Departure Clearance: The departure control frequency should be omitted from the departure clearance. In its place should be the phrase "no departure control available" or "departure offline".
2. Exiting the surface area: When an IFR departure approaches the limit of the Class D airspace, IFR aircraft should be issued the following instructions:
  
  "[callsign], leaving my airspace, frequency change approved."
3. Missed Approaches: Aircraft executing missed approaches shall be instructed to execute the missed approach procedure as published on the IAP chart, then shall resume the approach at their discretion. After pilot acknowledges, TWR issues a "frequency change approved." While executing any IFR missed approach, the aircraft shall NOT be instructed to remain on the TWR frequency. TWR shall NOT clear the aircraft for another approach.
  
  The exception to this rule is if the pilot specifically requests a "go around." If approved by TWR, the aircraft effectively changes to a visual approach, will remain in the traffic pattern, and will remain on TWR frequency. Appropriate separation must be provided.
IFR Preferred departure routes and departure clearances.
1. Pilots of IFR aircraft filing a flight plan:
  - without a SID, or,
  - with an inappropriate SID for the active runway plan and/or route, time of day, or aircraft class or equipment
  shall be asked if they can accept the appropriate DP, and then have their flight plan amended, unless the pilot has indicated "NO SID" or "NO CHARTS" in his flight plan comments.
2. If the pilot:
  - declines to accept a clearance with the appropriate DP for the runway plan and/or route, or,
  - indicates he does not have charts in his flight plan comments
  then the route assigned shall be "via runway heading, expect radar vectors to..." the transition fix of the appropriate DP and route segment based on the ZOA Preferred Routes listed in SOP_052. If the runway heading is not appropriate due to local traffic flows, alternate instructions will be listed in the SOP_050 Primary Airports SOP. If no radar facility is available, then remove the phrase "expect radar vectors to".
3. IFR Aircraft submitting a flight plan with a route that does not comply with ZOA preferred routes as listed in SOP_052 shall be issued a routing including the preferred route segment and requested to re-file an amended flight plan unless they have filed a route of "DIRECT" or "GPS DIRECT". For pilots filing "DIRECT" / "GPS DIRECT", the route assigned shall be "via runway heading, expect radar vectors to..." the transition fix of the appropriate DP and route segment, "...,then direct". If the runway heading is not appropriate due to local traffic flows, alternate instructions will be listed in the "primary airports" section of the facility SOP. If no radar facility is available, then remove the phrase "expect radar vectors to".
4. The pilot is not required to amend his flight plan to match the accepted clearance. If the pilot chooses not to amend the flight plan to match the accepted clearance, ATC may amend the flight plan, or else the downstream controller must be informed of the accepted clearance.
Oceanic Clearance and Release Procedure
1. When KZAK_FSS is operational, Oceanic Clearances must be obtained by DEL for all aircraft filed for oceanic routes R463 and R464 as follows:
  1. DEL shall apply a standard 7 minute estimate from clearance readback to departure (C2D) time.
  2. After clearance readback, aircraft shall remain in position and expect oceanic clearance in 5 minutes. Ex: "AAL1028. Readback correct. Hold for oceanic clearance. Expect clearance in 5 minutes".
  3. DEL shall consult the ground Estimated TCP Time for the oceanic route and add the standard 7 minute (C2D) estimate to derive the requested OC Time. Example: AAL1028 is filed R463 at KSFO. Clearance is readback at 17:06Z. Clearance to Departure (C2D) is estimated 7 minutes. Using the ZOA planning page from the KZAK web site, estimated arrival from KSFO to ADISN is 35 minutes. Therefore Estimated TCP time is 17:06Z + 7min + 35min = 17:48Z. Request OC for 17:48Z.
  4. Contact OAK_A_CTR and request OC. Example: "Req OC, AAL1028, FL350, ADISN 17:48Z".
  5. OAK_A_CTR will reply with operating initials if approved. Then inform the aircraft. Example: "AAL1028, Cleared oceanic. SFO alt 29.92, expect rwy 28L. Call ready for taxi."
  6. OAK_A_CTR will reply with a new OC Time if required. Delay the aircraft's departure as needed to meet the OC time. Example: Requested OC time was 17:48, OC is granted for 17:56. Gate hold the aircraft for 8 minutes. "AAL1028, Cleared Oceanic at 17:55Z. Expect taxi in 8 minutes."
  7. If OAK_CTR is not online, contact KZAK_FSS directly for OC.
2. Oceanic routes are authorized for Reduced Vertical Separation Minimums (RVSM). Pilots are required to use non-standard IFR altitudes. Authorized altitudes by route can be found on the KZAK website. Pilots should file initial IFR standard altitude in flight plan, and oceanic altitude in flight plan comments.
Tower Coordination and Departure Releases
1. TWR shall NOT use the radar handoff feature with the departure controller. When a positive rate of climb is apparent, TWR shall instruct departing aircraft to contact Departure as soon as possible.
  
  Likewise approach control shall not use the radar handoff feature to pass arrivals to TWR. They shall simply issue a frequency change to TWR frequency. This accurately models the lack of a full radar display terminal in the tower.
2. At the request of the departure controller, or as specified by sector SOPs, tower shall use "Release Procedures". TWR shall then obtain a release for each IFR departure by sending the following interphone message: [CALLSIGN] [DP.TRANSITION] [RUNWAY]. The release for IFR shall be requested when the aircraft reports ready for takeoff. Departure control will authorize release by replying with operating initials or specific instructions. Once authorization is obtained, the aircraft may be cleared for takeoff.
  
  Example:
  
  SFO_TWR: AAL1028 PORTE3.AVE 28L
  
  STS_APP: IE
3. Releases shall always be obtained for VFR departures from airports within Class B surface area at the time of inital contact. TWR shall include the direction of flight. The departure controller may respond with restrictions to be issued by TWR to the aircraft.
  
  Example:
  
  SFO_TWR: N104TP S-BOUND 28L
  
  STS_APP: RELEASED AT/BELOW 2500
4. Closed traffic will remain with the TWR controller and does not require a release. If an aircraft wishes to depart the pattern, TWR shall inform the departure controller of the VFR departure and direction of flight.