Phraseology — Page 104, Lesson 88

I want to walk you through the phraseology used in transponder communications and 8.33 kHz frequency operations, and then we’ll look at how to structure an initial message when contacting an aeronautical station. Let’s start with the transponder phraseology. The transponder is the equipment in your aircraft that replies to ground radar interrogations, and we use specific phrases to communicate about it. The first exchange you see is: “FASTAIR 345 ADVISE TYPE OF TRANSPONDER.” That’s ATC asking the pilot to state what kind of transponder is fitted. The pilot replies, “FASTAIR 345 TRANSPONDER CHARLIE.” ‘Charlie’ here refers to Mode C, which means the transponder can report altitude. Next, ATC says, “FASTAIR 345 SQUAWK 6411.” ‘Squawk’ is the verb we use for setting a specific four-digit code on the transponder. The pilot reads back the code: “6411 FASTAIR 345.” Then ATC might ask, “FASTAIR 345 CONFIRM SQUAWK,” and the pilot confirms by saying, “FASTAIR 345 SQUAWKING 6411.” Notice the word ‘squawking’ — that’s the present participle, meaning the code is currently set. If ATC wants you to re-enter the same code, they say, “FASTAIR 345 RESET 6411,” and you acknowledge with, “FASTAIR 345 RESETTING 6411.” That’s the action of pressing the reset button on the transponder. Now, a very important check: “FASTAIR 345 CHECK ALTIMETER SETTING AND CONFIRM LEVEL.” This is ATC asking you to verify your altimeter sub-scale setting and then report your current altitude or flight level. The pilot replies, “FASTAIR 345 ALTIMETER 1013 FLIGHT LEVEL 80.” So the altimeter is set to 1013 hectopascals, and the aircraft is at Flight Level 80 — that’s 8,000 feet on the standard pressure setting. Finally, ATC might ask, “FASTAIR 345 CONFIRM TRANSPONDER OPERATING.” If the transponder has failed, the pilot says, “FASTAIR 345 NEGATIVE TRANSPONDER UNSERVICEABLE.” ‘Negative’ means no, and ‘unserviceable’ means it’s not working. Now let’s move to 8.33 kHz phraseology. This refers to the channel spacing on VHF radios — 8.33 kHz spacing allows more frequencies to be available. The phraseology is very structured. If ATC wants to know if your radio can tune 8.33 kHz channels, they ask, “Confirm Eight Point Three Three.” The pilot replies, “Affirm Eight Point Three Three” if the radio is capable, or “Negative Eight Point Three Three” if it is not. Notice the exact wording: ‘Eight Point Three Three’ — never ‘eight point three three kilohertz’ in the phraseology. Similarly, for UHF capability — that’s Ultra High Frequency, used by military and some other services — ATC asks, “Confirm UHF.” The pilot says “Affirm UHF” if capable, or “Negative UHF” if not. There’s also a status regarding exemption. Some aircraft are exempt from having 8.33 kHz radios, usually older equipment. ATC asks, “Confirm Eight Point Three Three exempted.” The pilot says “Affirm Eight Point Three Three exempted” if they are exempt, or “Negative Eight Point Three Three exempted” if they are not exempt — meaning they must use 8.33 kHz. Now let’s look at the initial message structure. When flying under VFR — Visual Flight Rules — you might need to change frequency to contact an aeronautical station for three main reasons: to obtain a service like Flight Information Service (FIS) or Radar Information Service (RIS) from an Air Traffic Services Unit (ATSU); to get clearance to penetrate a MATZ — that’s a Military Air Traffic Zone; or to get clearance to enter controlled airspace under Special VFR (SVFR). The initial call should include your call sign and a request for the type of service you need. The ground station will reply with “GO AHEAD” — or in the UK, “Pass your message” — and then you send the full initial message. The exact information and the order it must be passed varies by unit, and the book gives a table. Let me walk through that table. For an ATSU, you include: call sign, type of aircraft, position, heading, level, intention, and type of service. The type of service has a tick in brackets — that means it’s optional if you already stated it in the initial call. For a MATZ, you include: call sign, type, position, heading, level, intention, and also ETA at the entry point — that’s Estimated Time of Arrival. For Special VFR, you include: call sign, type, position, heading, level, intention, and type of service. Notice that for SVFR, you do not include ETA entry point. So the key takeaway: the information required depends on whether you’re contacting an ATSU for a service, penetrating a MATZ, or entering controlled airspace under SVFR. Always include call sign, type, position, heading, level, and intention as a minimum, and add ETA for MATZ or type of service for ATSU and SVFR if not already stated. That covers the transponder phraseology, 8.33 kHz and UHF capability checks, and the structure of an initial VFR message.