Section 3. Operations

  1. SIGMETs and CWAs:
  1. The CWSU meteorologist is the focal point for the review of SIGMETs to determine application to the ARTCC area of responsibility and may issue a CWA to modify or redefine the SIGMET information.
  2. The CWSU meteorologist may also issue a CWA in advance of a SIGMET when the observed or the expected weather conditions meet SIGMET criteria or when conditions do not meet SIGMET criteria but are considered significant.
  3. The weather coordinator (WC) has the primary responsibility for the inter/intrafacility dissemination of AIRMETs (except over CONUS), SIGMETs, urgent PIREPs (UUA), routine PIREPs (UA), and CWAs, and must ensure that sufficient information is disseminated to facilitate the required alert broadcasts.


In recognition that there are several uses/definitions for the acronym CONUS, references herein to CONUS are specific to the contiguous United States (i.e., “lower 48”).


FAA Order JO 7210.3, Chapter 18, Section 26, Weather Management.
FAA Order JO 7110.65, Para 2-6-6, Hazardous Inflight Weather Advisory.

  1. Terminal ATC facilities must relay the SIGMET and the CWA information to towers under their jurisdiction.
  1. PIREPs:
  1. The WC is the focal point for handling PIREP requests and for the dissemination of urgent and routine PIREPs within the ARTCC and to terminal ATC facilities without Leased Service A System (LSAS) which are or may be affected.
  2. The CWSU meteorologist solicits PIREPs through the weather coordinator or directly from the controllers when required.
  1. Both solicited and unsolicited PIREPs that meet the urgent PIREP criteria must be distributed immediately via the LSAS.
  2. Solicited and unsolicited routine PIREPs must be distributed in a timely manner.
  1. PIREP classification: Categorize PIREPs as follows:
  1. URGENT: Weather phenomena reported by a pilot which represents a hazard or a potential hazard to flight operations. Disseminate reports of the following conditions as URGENT PIREPs:
  1. Tornadoes, funnel clouds, or waterspouts.
  2. Severe or extreme turbulence (including clear air turbulence).
  3. Severe icing.
  4. Hail.
  5. Low level wind shear.


Defined as wind shear within 2,000 feet of the surface.

  1. Volcanic eruptions and volcanic ash clouds.
  2. Detection of sulfur gases (SO2 or H2S), associated with volcanic activity, in the cabin.


The smell of sulfur gases in the cockpit may indicate volcanic activity that has not yet been detected or reported and/or possible entry into an ash-bearing cloud. SO2 is identifiable as the sharp, acrid odor of a freshly struck match. H2S has the odor of rotten eggs.

  1. Any other weather phenomena reported which are considered by the specialist as being hazardous or potentially hazardous to flight operations.
  1. ROUTINE: Classify all solicited and unsolicited PIREPs as routine unless otherwise indicated.

ARTCC air traffic managers must coordinate with other air traffic facilities in their area to ensure that adequate procedures are established for the receipt and distribution of NOTAMs. NOTAM distribution may be accomplished via the Aeronautical Information System Replacement (AISR) or accessed at> as a source for NOTAM information.


Although magnetic radials are used in planning airways/routes, conversion to true radials is required for designation. The final magnetic radials are not determined until the airspace action is charted. As a result, differences from planned magnetic radials may occur in the conversion of true to magnetic radials. Differences may also occur later due to changes in the magnetic variation, which is recomputed every 5 years. These differences could contribute to the misapplication of the VFR altitude hemispheric rule. Therefore, ARTCC air traffic managers must conduct a continuing review of the airway and jet route structures and proposed new airspace cases and bring any differences to the attention of the En Route and Oceanic Operations Service Area Office.

  1. The Flight Data Unit (FDU) is responsible for processing and disseminating operational information necessary for NAS operations.
  2. The FDU must provide system support during outage(s) of critical systems and/or software. These responsibilities include data recovery, manual processing, and disseminating information or data products as necessary for safe and efficient operations.
  3. The Air Traffic Manager (ATM) must:
  1. Ensure all FDU responsibilities and procedures listed below are established in local orders or directives.
  2. Assign additional duties of a recurring nature based on unique facility requirements.
  3. Provide FDU specialists a copy of, or access to, the following;
  1. FAA Order JO 7110.10, Flight Services.
  2. FAA Order JO 7110.65, Air Traffic Control.
  3. FAA Order JO 7900.5, Surface Weather Observing-METAR.
  4. FAA Order 7930.2, Notices to Air Missions (NOTAM).
  5. Position binder, which includes:
  1. Procedures for accomplishing assigned position related duties and responsibilities.
  2. Examples and formats for seldom used procedures.
  3. Cross references to documents and lists contained in other publications which may be used where applicable.
  1. Unless otherwise specified in a facility directive or a letter of agreement, the Flight Data Communications Specialist (FDCS) performs the following:
  1. Flight Plan Data.
  1. Process domestic flight plan(s) proposals, corrections, amendments, and remove strip requests.
  2. Process international flight plan(s) proposals, corrections, amendments, remove strip requests, and departure messages.
  3. Process military flight plans.
  4. Provide data search assistance for Search and Rescue (SAR) information requests.
  1. Weather Products:
  1. Support the TMU weather coordinator with inter/intrafacility dissemination of the weather data products described in the Weather Management section of this order. This should include both urgent PIREPs (UUA) and routine PIREPs (UA).


FAA Order JO 7210.3, Para 18-26-4 b1, Weather Management.

  1. Provide inter/ intrafacility dissemination of international weather products as needed.
  2. Perform altimeter and weather data checks and system updates as required.
  3. Provide backup services for terminal facility PIREP and METAR entries.


FAA Order JO 7110.65, Para 2-6-3c, Weather Information.

  1. NOTAMs:
  1. Process and disseminate FDC, Special Use Airspace (SUA), and Temporary Flight Restriction (TFR) NOTAMs.
  2. Provide assistance with formatting and inputting Special Activity Airspace (SAA) NOTAMs.
  3. Process and disseminate NOTAM D information as necessary, to include ERIDS backup services.
  1. System/Administrative Messages: Process and disseminate the following messages:
  1. GENOTs,
  2. CIRNOTs,
  3. Oceanic track,
  4. ALTRV movement/change.
  1. Classified National Security Information (CNSI) and Communications Security (COMSEC): Handle, safeguard, and protect CNSI and COMSEC material in accordance with national policies, FAA orders, and local SOPs.
  2. Clearance Relay:
  1. Responds to telephone requests for ATC clearances received from pilots by contacting the appropriate sector within the ARTCC or approach control facility and relays clearance issued to the pilot verbatim.
  2. Advises appropriate ARTCC sector or approach control facility of IFR Flight Plan cancellations received over the telephone.

ARTCCs must use the procedures as outlined in FAA Order 7930.2, Notices to Air Missions (NOTAM), paragraph 6-1-2, Special Activity Airspace (SAA), when MTR or MOA activity is scheduled to occur at other than published or charted times.