Section 6. En Route Flight Advisory Service (EFAS)
The purpose of EFAS, radio call “FLIGHT WATCH”
(FW), is to provide en route aircraft with timely and
pertinent weather data tailored to a specific altitude
and route using the most current available sources of
aviation meteorological information.
EFAS/Flight Watch outlets are listed in the Airport/Facility Directory (AFD).
4-6-2. POSITION RESPONSIBILITIES
Prior to assuming the duties of the flight watch
a. Perform a thorough selfbriefing by reviewing
all pertinent weather data.
b. When relieving a specialist on the flight watch
position, obtain a preduty briefing from the person
c. When appropriate, obtain a briefing of current
and forecast weather within the flight watch area
(FWA) from the CWSU of the associated air route
traffic control center (ARTCC). (See para 465.)
d. Maintain currency of weather conditions and
trends while assigned the flight watch position by
reviewing new or revised meteorological issuances
and by observing weather trends contained in current
weather reports and PIREPs.
4-6-3. OPERATING PROCEDURES
a. Tailor en route flight advisories to the phase of
flight that begins after climb out and ends with
descent to land. Current weather and terminal
forecast at the airport of first intended landing and/or
the alternate airport must be provided on request.
When conditions dictate, provide information on
weather for alternate routes and/or altitudes to assist
the pilot in the avoidance of hazardous flight
conditions. Advise the pilot to contact the adjacent
FWA when adverse weather conditions along the
intended route extend beyond the FWA.
b. EFAS must not be used for routine inflight
services; for example, flight plan filing, position
reporting, or full route (preflight) briefings. If a
request for information is received that is not within
the scope of flight watch, advise the pilot of the
appropriate FSS to contact.
“Cessna Four Seven Five Eight Xray, Cleveland Flight
Watch, contact Altoona Radio on one two two point four
to file your flight plan.”
c. Suggest route or destination changes to avoid
areas of weather which in the judgment of the
specialist constitute a threat to safe flight.
d. Alert the associated CWSU or WFO
immediately of reported or observed significant
weather that is not included in aviation forecasts.
a. Use frequency 122.0 MHz to provide flight
watch services to aircraft below FL 180.
b. Use the assigned discrete frequency to provide
flight watch services to aircraft at FL 180 and above.
This frequency can also be used for communications
with aircraft below FL 180 when communication
c. Aircraft operating at FL 180 or above that
contact flight watch on frequency 122.0 MHz should
be advised to change to the high altitude discrete
frequency for Flight Watch.
(Aircraft identification) (facility) FLIGHT WATCH, FOR
SERVICE AT YOUR ALTITUDE. CONTACT FLIGHT
WATCH ON (frequency).
d. Avoid the simultaneous keying of two or more
transmitters on the same frequency. This action can
block or hinder communications.
Frequency 122.0 MHz RCF outlets are geographically
located to ensure communications coverage at 5,000 feet
AGL and above over the conterminous United States.
High altitude discrete frequency RCF outlets are
geographically located to ensure communications
coverage between FL 180 and FL 450 over the EFAS
facility's area of responsibility. Communications practices should be guided by these restrictions.
4-6-5. NWS SUPPORT TO EFAS
The NWS support function for EFAS is as follows:
a. The associated CWSU is designated as the
primary support facility for each flight watch area.
The CWSU should be contacted at least once per shift
for a general briefing of meteorological conditions
which are impacting, or expected to impact, aviation
weather within the flight watch /ARTCC area.
Due to assigned priorities, the CWSU meteorologist may
not be able to provide indepth briefing service for up to
2 hours after the start of the first shift of the CWSU unit.
(See FAA Order JO 7210.3, Para 1436, National
Weather Service (NWS) Support, for establishment of
b. During the period when the CWSU is not
available to provide consultation service, WFOs are
responsible for responding to EFAS facility requests
regarding weather conditions prevailing within the
WFO area of responsibility. The EFAS specialist
should contact the responsible WFO directly for
clarification of forecasts or questions concerning
products originated by the WFO.
The ARTCC/EFAS area may encompass multiple WFO
c. Consult with the Aviation Weather Center
(AWC), as appropriate, when further information or
clarification is needed regarding WS, WST, WA, and
4-6-6. PILOT WEATHER REPORTS
a. Actively solicit and disseminate PIREPs in
accordance with Chapter 9, Section 2. Additionally,
PIREPs concerning winds and temperature aloft,
wind shear, turbulence, and icing must be solicited
and disseminated when one or more of these
conditions or criteria exist. Flight watch specialists
must solicit sufficient PIREPs to remain aware of
b. Maintain a graphic display of pertinent PIREPs
within the flight watch area. Periodically review the
display, and actively solicit additional PIREPs when
necessary to ensure completeness and accuracy of the
c. Requests for special solicitation of PIREPs
from other facilities or the NWS must be honored as
rapidly as operations permit.
4-6-7. GRAPHIC WEATHER DISPLAY
a. Prior to assuming flight watch duties, the
specialist must review, as a minimum, the graphic
information listed below (if available). After
assuming duties, the specialist must continue to
review graphic and written data as needed during the
watch to update and maintain a thorough knowledge
of weather synoptic and forecast information
affecting aviation operations.
1. Weather Depiction.
2. Surface Analysis.
3. Forecast Winds Aloft.
4. GAIRMET Graphic.
5. 12 and 24 hour low-level significant
6. 36and 48 hour low-level significant
7. High-level significant weather prognosis.
8. Freezing level graphic.
9. Freezing level analysis.
10. *Current Icing Product (CIP).
11. *Forecast Icing Product (FIP).
12. *Graphical Turbulence Guidance (GTG).
13. 850 MB upper air analysis.
14. 700 MB upper air analysis.
15. 500 MB upper air analysis.
16. 300 MB upper air analysis.
17. 250 MB upper air analysis.
18. 200 MB upper air analysis.
19. 500 MB heights and vorticity analysis.
20. 500 MB heights and vorticity prognosis.
21. Severe weather outlook.
22. Lifted index analysis.
23. National weather radar summary.
24. Maximum temperature 24 and 36 hour
25. Minimum temperature 24 and 36 hour
*Denotes weather products that are supplementary. They
may only be used to enhance situational awareness. When
discrepancies are noted, the specialist must base their
decision on the primary weather product.
b. Access local and remote weather displays as
necessary to maintain current knowledge of
precipitation intensity, movement, and coverage.
Provide pertinent realtime weather radar information that will directly impact the aircraft's flight.
4-6-8. INTERRUPTIONS TO SERVICE
Notification of temporary outages, either equipment
or operational, must be made in accordance with FAA
Order JO 7930.2, Notices to Airmen (NOTAM). In
order to provide continuous service, notify the
specialist responsible for the adjacent flight watch
area of outages.
a. Emergency situations must be handled in
accordance with Chapter 5.
b. When working an aircraft in an emergency
situation over a remote outlet, the normal procedure
is to provide assistance on the initial contact
frequency. Flight watch specialists should bear in
mind that air traffic facilities based at, or near to, the
remote location may be in a better position to assist
the pilot. A decision to affect a frequency change
should be based on the situation and circumstances
involved in the emergency.