Radio - Flight Service Station (FSS)

How to communicate with a Flight Service Station (FSS) in-flight

References

• AIM Section 2. Radio Communications Phraseology and Techniques, section 4−2−3. Contact Procedures
• FAA Pilot/Controller Glossary
• FAA VFR Sectional and Terminal Charts

Overview

Communicating with Flight Service in-flight is a bit more complicated than other in-flight communications. For one thing, frequency and facility selection has many more variables than simply looking up a tower or CTAF frequency for your destination airport, or getting an explicit hand-off from one ATC controller to another. When communicating with flight service you need to determine the "best" facility and frequency to use given your present location. This usually means finding a nearby VOR or RCO that provides remote FSS communications and then determining the appropriate frequency to use to contact FSS.

FSS - Flight Service Station

From the Pilot/Controller Glossary:

FLIGHT SERVICE STATION (FSS) − An air traffic facility which provides pilot briefings, flight plan processing, en route flight advisories, search and rescue services, and assistance to lost aircraft and aircraft in emergency situations. FSS also relay ATC clearances, process Notices to Airmen, broadcast aviation weather and aeronautical information, and advise Customs and Immigration of transborder flights. In Alaska, FSS provide Airport Advisory Services.

As described above, flight service stations can perform a number of useful services to the pilot. But communicating with FSS while in the air can be less than straightforward. FSS communication relay facilities are typically co-resident with VORs, but are sometimes also available via Remote Communications Outlets (RCO). An RCO operates pretty much like a VOR with respect to communicating with FSS. The information needed to communicate with Flight Service via a VOR or RCO is provided in a communication box associated with a VOR or RCO on sectional and terminal area charts.

How to read a communication box is explained in the chart legend:

Many VORs provide two-way FSS communication on 122.2, and the emergency frequency 121.5 (aka "guard"). This is common enough that these frequencies are typically not explicitly listed above the communications box. If a VOR supports alternate (or additional) frequencies then they will be listed directly above the communication box.

121.5 is reserved for emergency use — but in an emergency don't hesitate to use it if needed! Note that acceptable use of 121.5 includes locating/reconnecting aircraft that sometimes go missing between hand-offs from one ATC controller or sector to the next and this is the typical use of 121.5 as "guard." (Most commercial aircraft, GA pilots on long cross-country flights, and aircraft flying in the flight levels continually monitor guard, aka 121.5, for this very reason.)

In some cases you must use split frequency communications to communicate with FSS via a VOR. In this case the frequency listed above the VOR data box will be immediately followed by the letter 'R' (indicating that FSS will only receive, not transmit, on this frequency). This frequency will almost always be 122.1R. To operate in split mode you would configure your COM radio to transmit on 122.1, your NAV radio to receive on the published VOR frequency, and your audio panel to route the audio from both to your headset or speaker. If available, make sure to activate the notch filter to remove the Morse code ID from the audio output after copying the VOR identifier and setting the volume appropriately.

Before contacting FSS, if you are currently flying IFR, or are flying VFR with flight following, you will typically need to request permission to leave the frequency for a few minutes to allow you to talk with flight service. This is usually done with an exchange with ATC similar to this:

You: "Oakland Center, Cessna 12345 would like to go off frequency for a few minutes to talk with flight service."

Center: "Roger. Cessna 12345, approved as requested. Report back on."

Note: The specialist working FSS is typically tasked with a very large area of coverage. Keep in mind that at any given moment they may be busy helping a number of other pilots. They also have multiple radios to mange for both receiving and transmitting. When you contact FSS you need to give them enough information so that they can zero in on the right radios to use for communicating with you. You will also need to allow them adequate time to reply (waiting up to 30 seconds or longer for an initial reply). It is also standard practice to use "over" at the end of each transmission with FSS due the due to the additional challenges of FSS communications.

To that end, when making your initial call to FSS you should follow the guidance of the AIM (see AIM 4−2−3. Contact Procedures for details) which should go something like this:

Two-way: “Rancho Radio, Cessna One Zero Zero Four Echo, 10 miles North West Red Bluff VOR, One Two Two Point Four. Over”

Split com: “Rancho Radio, Cessna One Zero Zero Four Echo, 10 miles North East Chico VOR, Transmitting One Two Two Point One, Listening Chico VOR. Over”

Here are some examples of actual sectional chart communication boxes and how to interpret them: