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Licence privileges & documents

What the FRTOL actually is

The Flight Radiotelephony Operator's Licence (FRTOL) is issued by the UK CAA and is the licence that lets you legally operate radio equipment on an aircraft using RT procedures. It is separate from your pilot's licence (NPPL, LAPL, PPL etc) - you need both to fly and transmit legally, though the practical skill test is often combined with your flight test.

Who needs one and the exemption

  • Anyone transmitting on an aircraft radio in controlled or notified airspace, or using an aircraft callsign, needs the FRTOL (or is flying under the direct supervision of someone who holds one).
  • A pilot flying solo under instruction can operate the radio without holding the FRTOL themselves, provided a qualified instructor is monitoring and available to take over communications if needed.
  • Once qualified, a pilot must NOT operate radio unsupervised until the FRTOL is actually issued - passing the written exam and practical test is not enough on its own.

How you get it

  • Pass the written theory exam (this exam) - multiple choice, testing RT procedures, phraseology and law.
  • Pass a practical assessment - usually done in the air or on a simulator/ground station with an authorised examiner, showing you can use correct phraseology in real scenarios.
  • Apply to the CAA with the pass evidence to have the licence issued.

Privileges once issued

  • The FRTOL has UK-wide validity and, importantly, is recognised for use on aircraft registered in ICAO member states when operating under ICAO-standard phraseology - it is not restricted to UK-registered aircraft only.
  • It does not expire and does not need periodic renewal, unlike a medical certificate or some licence ratings - once issued it remains valid indefinitely unless suspended or revoked by the CAA.
  • It permits the use of VHF RT for both controlled and uncontrolled (open FIR) airspace communications, including distress and urgency calls.

Documents to know

  • The FRTOL itself is the legal authorisation to transmit - keep confirmation of it available, though you are not legally required to carry the physical certificate in the aircraft the way you might for other documents.
  • Separately, the aircraft must carry the correct licensing/registration documents; the pilot's flying licence and medical are the pilot-side paperwork - do not confuse FRTOL privileges with pilot licence privileges, they are two different documents with two different purposes.

Common mistakes

  • Thinking the FRTOL is part of the PPL/NPPL - it is a completely separate CAA licence.
  • Believing it expires or needs renewal - it does not.
  • Assuming you can transmit unsupervised the moment you pass the exam - you need the licence actually issued.
  • Forgetting it has ICAO-wide recognition, not just UK.
  • The FRTOL is issued by the UK CAA and is separate from your pilot's licence (PPL/LAPL/NPPL).
  • You need both a valid pilot licence and the FRTOL (or supervision by an FRTOL holder) to transmit legally on an aircraft radio.
  • A student pilot flying solo can use the radio without holding the FRTOL if a qualified instructor is monitoring and can take over.
  • To gain the FRTOL you must pass a written theory exam plus a practical RT assessment, then have the CAA issue the licence.
  • The FRTOL does not expire and requires no periodic renewal once issued.
  • The FRTOL is recognised in all ICAO member states, not just for UK-registered aircraft.
  • You must not operate radio unsupervised until the licence has actually been issued by the CAA, even after passing both tests.
  • The FRTOL covers use of VHF RT in controlled and uncontrolled airspace, including distress (MAYDAY) and urgency (PAN PAN) calls.
  • The FRTOL is a document authorising the operator, not the aircraft - it travels with the person, not the airframe.
  • Suspension or revocation by the CAA can remove FRTOL privileges even though the licence has no fixed expiry date.
What does FRTOL stand for and who issues it?
Flight Radiotelephony Operator's Licence, issued by the UK CAA.
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Is the FRTOL the same as your PPL or NPPL?
No - it is a completely separate licence from your flying licence.
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Can a student pilot flying solo use the radio without an FRTOL?
Yes, if a qualified instructor is monitoring and able to take over communications.
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What two tests must you pass to gain the FRTOL?
A written theory exam and a practical RT assessment.
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Does the FRTOL expire?
No - once issued it is valid indefinitely, no periodic renewal needed.
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Is the FRTOL valid only in the UK?
No - it is recognised across ICAO member states when using ICAO-standard phraseology.
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Once you pass both the theory and practical tests, can you transmit unsupervised immediately?
No - you must wait until the CAA has actually issued the licence.
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Does the FRTOL authorise use of distress and urgency calls?
Yes - it covers MAYDAY and PAN PAN calls as well as routine RT.
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Is the FRTOL tied to the aircraft or the person?
The person - it is a personal operator licence, not an aircraft document.
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What can remove FRTOL privileges despite it having no expiry?
Suspension or revocation of the licence by the CAA.
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What kind of exam is the FRTOL theory test?
A multiple-choice exam covering RT procedures, phraseology and relevant law.
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Who assesses the practical RT test?
An authorised examiner, usually in the air or via simulator/ground station.
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What airspace types does the FRTOL cover for VHF RT use?
Both controlled and uncontrolled (open FIR) airspace.
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Phraseology & message categories

Why phraseology matters

Standard phraseology exists so messages are understood first time, in noisy conditions, by pilots and controllers who may not share a first language. The CAA examines both the exact wording and your understanding of which message type takes priority.

The three message categories

  • Distress - 'MAYDAY MAYDAY MAYDAY', for grave and imminent danger requiring immediate assistance (fire, engine failure, imminent forced landing). Always has absolute priority over all other transmissions.
  • Urgency - 'PAN PAN PAN PAN PAN PAN', for a condition concerning safety that does not require immediate assistance (partial engine trouble, uncertain of position, minor injury on board). Ranks below Distress but above all other traffic.
  • Safety - prefixed 'SECURITE' (said three times), used for navigational or meteorological warnings such as bad weather reports.

Priority order

Distress beats Urgency beats Safety beats all normal working traffic. Once a MAYDAY is heard, every station must stay silent unless called by the aircraft in distress or needed to help - this is called radio silence and is often imposed by 'STOP TRANSMITTING - MAYDAY'.

Key wording rules

  • Numbers are transmitted digit by digit (one-two-zero not one hundred and twenty), except whole hundreds and thousands.
  • Level changes always use 'climb' or 'descend', never 'up' or 'down'.
  • Read back is mandatory for: level instructions, heading and speed instructions, runway-in-use, altimeter settings, SSR codes, and any conditional clearance.
  • 'Roger' means 'I have received all of your last transmission' - it is NOT an acknowledgement of an instruction and must never replace a proper readback.
  • 'Wilco' means 'I understand and will comply' - use it when no full readback is required.
  • Say again, spell using the phonetic alphabet, and confirm are the standard tools for resolving confusion.
  • Callsigns should be abbreviated only after the ground station has used the abbreviated form first.

Common mistakes

Students often mix up Roger and Wilco, forget that MAYDAY must be said three times, or try to give a distress call using PAN PAN. Another frequent error is reading back only part of an instruction, or using casual phrases ('okay', 'yep') instead of the approved words - the CAA marks these as errors even if the meaning is understood.

Cancelling an emergency

An aircraft that declared MAYDAY or PAN PAN must cancel it clearly once the emergency is over, using the phrase '(callsign) - cancel distress' or '(callsign) - cancel urgency', so other stations know normal working can resume.

  • MAYDAY is said three times and signals grave and imminent danger needing immediate assistance.
  • PAN PAN is said six times (three pairs) and signals an urgency condition not requiring immediate assistance.
  • Distress messages have absolute priority over all other radio traffic, including PAN PAN.
  • SECURITE (said three times) is used for safety messages such as navigation or weather warnings.
  • Roger means 'message received' only - it never confirms compliance with an instruction.
  • Wilco means 'understood and will comply' - use it in place of Roger when accepting an instruction.
  • Full readback is mandatory for level, heading, speed, runway, altimeter setting, and SSR code instructions.
  • Numbers are transmitted digit by digit except whole hundreds and thousands, e.g. 3400 feet is 'three thousand four hundred feet'.
  • Use 'climb' or 'descend' for level changes, never 'up' or 'down'.
  • Once MAYDAY is transmitted, all other stations must maintain radio silence unless called or assisting.
  • Cancel an emergency clearly using '(callsign) - cancel distress' or '(callsign) - cancel urgency'.
  • The phonetic alphabet must be used whenever spelling callsigns, place names, or clarifying letters/numbers.
What phrase and how many times is a distress call announced?
MAYDAY MAYDAY MAYDAY - said three times.
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What phrase and how many times is an urgency call announced?
PAN PAN PAN PAN PAN PAN - said six times (three pairs).
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What is the priority order of the three message categories?
Distress, then Urgency, then Safety, then normal traffic.
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What does Roger mean in radio phraseology?
I have received all of your last transmission - it does not confirm you will comply.
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What does Wilco mean?
I understand your message and will comply with it.
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Which instructions require a full readback?
Level, heading, speed, runway-in-use, altimeter settings, SSR codes, and conditional clearances.
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How are numbers normally transmitted on the radio?
Digit by digit, e.g. 120 is 'one-two-zero', except whole hundreds and thousands.
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What words must be used for level changes instead of 'up' or 'down'?
'Climb' and 'descend'.
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What prefix is used for a safety message such as a weather warning?
SECURITE, said three times.
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What must other stations do once a MAYDAY call is heard?
Maintain radio silence unless they are the station called or are assisting the aircraft in distress.
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How does a pilot cancel a declared emergency?
By transmitting '(callsign) - cancel distress' or '(callsign) - cancel urgency' once the situation is resolved.
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Give an example situation that would warrant a PAN PAN call.
Uncertain of position, minor technical issue, or a minor injury on board - concerning but not immediately life-threatening.
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Give an example situation that would warrant a MAYDAY call.
Engine fire, total engine failure, or an imminent forced landing - grave and imminent danger.
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Why is standard phraseology used instead of everyday language?
To ensure messages are understood correctly first time, in poor conditions, by speakers of different first languages.
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What tool is used to spell out callsigns or confusing words clearly?
The ICAO phonetic alphabet (Alpha, Bravo, Charlie, etc).
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Aerodrome communications

Why aerodrome communications matter

Most of your FRTOL exam is built around a standard visit to an aerodrome - taxi, takeoff, circuit, landing. Getting the phraseology and sequence right here covers a huge chunk of the practical test.

The station types you will meet

  • ATC (Air Traffic Control) - callsign suffix TOWER, GROUND, APPROACH, RADAR. Gives instructions and clearances you must comply with.
  • AFIS (Aerodrome Flight Information Service) - callsign suffix INFORMATION. Gives information and advice, not instructions - the pilot remains fully responsible for separation.
  • A/G (Air-Ground) - callsign suffix RADIO. Basic traffic information only, operated by someone who may not be a qualified controller. No ATC service implied.

Know which service type you are dealing with because the wording you receive - and how binding it is - changes with each one.

The standard sequence of calls

1. Initial call / request start-up - state callsign, type, stand, request (eg PPR, information, taxi).

2. ATIS or request for information - get QNH, runway in use, wind, and any special instructions before you call for start or taxi.

3. Taxi clearance - given as a specific route to a holding point, eg 'Taxi to holding point Alpha, runway 27, QNH 1013.' You must read back the runway, any holding point, and any conditional clearance in full.

4. Departure/takeoff clearance - 'G-ABCD, wind 250/8, runway 27, cleared for take-off.' Line up clearances are separate from take-off clearances - never assume one implies the other.

5. Circuit and joining calls - standard overhead join at 2,000 ft above aerodrome level (unless notified otherwise), descending on the dead side to circuit height, typically 1,000 ft AGL.

6. Landing clearance - 'cleared to land' must be received before crossing the runway threshold; a 'continue approach' is not a landing clearance.

Read-back rules - the examiner loves this

You MUST read back in full: runway-in-use, altimeter settings (QNH/QFE), level/altitude/height instructions, heading instructions, VDF information, frequency changes, transponder codes, and any conditional clearance (eg 'line up after landing traffic'). Getting these read-backs word-perfect and complete is one of the most heavily tested skills.

Common mistakes to avoid

  • Confusing QNH (altimeter shows altitude AMSL) with QFE (altimeter shows height above the aerodrome) - always state which one you are given and using.
  • Reading back only part of a conditional clearance - the whole condition must be repeated back.
  • Treating an AFIS 'traffic is...' call as a clearance - it is information only, you decide.
  • Forgetting to change to the next frequency when instructed, or reading back the wrong frequency.
  • Not stating your full callsign on first contact, then abbreviating only once ATC has used the abbreviated form back to you first.

Emergency and non-standard aerodromes

At an aerodrome with no ATC or AFIS, use blind transmissions on the notified frequency at key points (before taxi, entering runway, joining, downwind, final) so other traffic is aware of your intentions - this is the 'self-announce' technique.

  • ATC gives instructions (mandatory compliance); AFIS gives information/advice only, with the pilot retaining separation responsibility; A/G (RADIO) gives basic traffic information with no ATC service implied.
  • Callsign suffixes tell you the service: TOWER/GROUND/APPROACH/RADAR = ATC, INFORMATION = AFIS, RADIO = A/G.
  • You must read back in full: runway-in-use, QNH/QFE, altitude/height/level instructions, headings, VDF bearings, frequency changes, transponder (squawk) codes, and any conditional clearance.
  • A standard overhead join is at 2,000 ft above aerodrome level unless a different height is notified.
  • Standard circuit height at most UK aerodromes is 1,000 ft AGL unless notified otherwise.
  • 'Cleared to land' must be received before crossing the runway threshold - a 'continue approach' call is NOT a landing clearance.
  • QNH gives an altimeter reading of altitude above mean sea level; QFE gives an altimeter reading of height above the aerodrome - never mix the two up in a read-back.
  • A line-up clearance and a take-off clearance are two separate clearances - never assume being told to line up also clears you for take-off.
  • At an aerodrome with no ATC or AFIS, pilots self-announce with blind transmissions at key points: before taxi, entering the runway, joining, downwind, and final.
  • Use your full callsign on first contact and until ATC/AFIS abbreviates it back to you - only then may you abbreviate.
  • PPR (Prior Permission Required) and ATIS information should normally be obtained/checked before requesting start-up or taxi.
  • A conditional clearance (eg 'line up after landing traffic') must have its full condition read back, not just acknowledged.
What does an ATC unit provide compared with an AFIS unit?
ATC provides instructions that must be complied with; AFIS provides information and advice only - the pilot remains responsible for separation.
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What callsign suffix indicates an Air-Ground (A/G) station?
RADIO - basic traffic information only, no ATC service implied.
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What must you read back regarding a runway instruction?
The full runway-in-use, in full, every time it is given.
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What altitude is a standard overhead join flown at, unless notified otherwise?
2,000 ft above aerodrome level.
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What is standard circuit height at most UK aerodromes?
1,000 ft AGL, unless a different height is notified.
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What phrase constitutes an actual landing clearance?
'Cleared to land' - a 'continue approach' call is NOT a landing clearance.
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What is the difference between QNH and QFE?
QNH: altimeter shows altitude above mean sea level. QFE: altimeter shows height above the aerodrome.
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Does a line-up clearance also mean you are cleared for take-off?
No - line-up and take-off clearances are separate and must each be given explicitly.
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How should you behave at an aerodrome with no ATC or AFIS service?
Self-announce with blind transmissions at key points: before taxi, entering the runway, joining, downwind, and final.
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When can you start using an abbreviated callsign?
Only after ATC or AFIS has used the abbreviated form back to you first - use the full callsign until then.
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What should you obtain before requesting start-up or taxi?
ATIS information (or equivalent) and, if required, PPR (Prior Permission Required).
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What must be included in a read-back of a conditional taxi or take-off clearance?
The entire condition must be repeated back in full, not just acknowledged.
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Which items must always be read back in aerodrome communications?
Runway-in-use, QNH/QFE, altitude/height/level instructions, headings, VDF information, frequency changes, and transponder codes.
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What does the callsign suffix TOWER, GROUND, APPROACH or RADAR indicate?
That the unit is an Air Traffic Control (ATC) service, issuing instructions rather than just information.
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If AFIS tells you 'traffic is a Cessna on final', is this a clearance?
No - it is information only; the pilot decides how to act, since AFIS does not provide separation.
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En-route & service types

What is en-route service?

Once you have left the immediate circuit environment and are transiting between aerodromes, you will use one of several UK airspace service types depending on where you are flying and what class of airspace you are in.

In Class G (uncontrolled) airspace the main services from a Flight Information Service Officer (FISO) or Air Traffic Control Officer (ATCO) are:

  • Basic Service - a Flight Information Service plus traffic information may be given as workload allows, but there is NO monitoring of your flight by the controller and NO deconfliction advice. You keep your own separation and lookout at all times.
  • Traffic Service - a surveillance-based service. The controller gives you traffic information on relevant aircraft but leaves collision avoidance entirely to you. No specific deconfliction instructions are issued.
  • Deconfliction Service - surveillance-based and the most protective Class G service. The controller aims to keep you a specified distance from other traffic (5nm laterally or 3000ft vertically is the standard target) and gives you headings or levels to achieve this.
  • Procedural Service - a non-surveillance service for airspace with no radar, using procedural methods (position reports, timing, levels) to separate traffic.

Flight Information Service (FIS)

An Air/Ground (A/G) station, run by a radio operator rather than a controller, provides basic aerodrome and weather information only - it is NOT an ATC unit and gives no traffic separation or instructions.

London Information / Scottish Information

These are FIR-wide Flight Information Services covering the London and Scottish FIRs. They offer a Basic Service and can be a very useful source of traffic and weather information when transiting long distances, but again they do not provide separation.

En-route in Controlled Airspace

Within a Control Zone (CTR) or Control Area (CTA) you are under a full ATC service (usually Radar Control), receiving mandatory instructions, and you must comply.

Common mistakes

  • Confusing Basic Service (no monitoring) with a Traffic Service (monitored, traffic info given).
  • Assuming Traffic Service or Deconfliction Service removes your responsibility to look out - it never does.
  • Forgetting that A/G operators are NOT controllers and cannot give instructions.
  • Mixing up the two Information Services - London Information covers the south, Scottish Information the north.

Always state clearly which service you are requesting, and read back any level, heading or squawk instructions in full.

  • Basic Service = FIS only, no monitoring, no traffic deconfliction, pilot keeps own separation
  • Traffic Service = surveillance-based, controller passes traffic information, pilot avoids collisions themselves
  • Deconfliction Service = surveillance-based, controller aims for 5nm lateral or 3000ft vertical separation from traffic
  • Procedural Service = non-surveillance, used where no radar cover exists, relies on position reports and levels
  • A/G (Air/Ground) stations are run by radio operators, not controllers, and give info only, never instructions
  • London Information and Scottish Information provide a Basic Service across their respective FIRs
  • In a CTR or CTA you receive a full ATC service such as Radar Control and must comply with instructions
  • Deconfliction Service is the most protective Class G service but is still not a guarantee against all traffic
  • Traffic Service gives no specific avoiding action, unlike Deconfliction Service which does
  • Pilots must always maintain their own separation and lookout under Basic and Traffic Service
What does a Basic Service provide?
Flight Information only, plus traffic info as workload allows; no monitoring, no deconfliction advice
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What is the key difference between Traffic Service and Basic Service?
Traffic Service is surveillance-based and the controller actively passes traffic information; Basic Service does not
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What separation does a Deconfliction Service aim to provide?
5nm laterally or 3000ft vertically from conflicting traffic
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Under a Traffic Service, who is responsible for avoiding other aircraft?
The pilot - the controller gives traffic info only, not avoiding action
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What is a Procedural Service used for?
Separating traffic in airspace with no radar cover, using position reports, timing and levels
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Is an Air/Ground (A/G) operator a controller?
No - they are a radio operator who provides information only, never ATC instructions
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Which FIS covers the southern UK FIR?
London Information
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Which FIS covers the northern UK FIR?
Scottish Information
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What service level do you normally receive inside a Control Zone (CTR)?
A full ATC service such as Radar Control, and you must comply with instructions
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Which Class G service is the most protective?
Deconfliction Service
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Does a Deconfliction Service remove the pilot's need to keep a lookout?
No - the pilot must always maintain their own lookout regardless of service type
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What must you always do after receiving a level, heading or squawk instruction?
Read it back in full
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Name the four main Class G airspace services
Basic Service, Traffic Service, Deconfliction Service, Procedural Service
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Emergency communications

Emergency communications: why this matters

When things go wrong in the air, the radio is your lifeline. The FRTOL exam expects you to know the exact words, the order to say them in, and which frequency to use without hesitating.

The two levels of urgency

There are two distinct message types, and mixing them up is a classic mistake.

  • MAYDAY (said three times): grave and imminent danger, requiring immediate assistance - engine failure, fire on board, structural damage, being about to force-land.
  • PAN PAN (said three times): urgency condition concerning the safety of an aircraft or person, but not requiring immediate assistance - lost, low fuel, minor technical issue, unwell passenger.

Which frequency to use

  • Use the frequency you are currently working on first - do not waste time retuning if someone can already hear you.
  • If that gets no response, or you are not in contact with anyone, use 121.5 MHz, the international VHF emergency (guard) frequency, monitored by ATC units and many aircraft.
  • Only change frequency if your current one genuinely will not work.

The distress message structure

Memorise this order (mnemonic: MAYDAY, who, where, what, how many, help needed):

  • MAYDAY MAYDAY MAYDAY
  • Station being called (if known) or 'all stations'
  • Aircraft callsign
  • Type of aircraft
  • Nature of the emergency
  • Intentions of the pilot
  • Present position, level/altitude and heading
  • Number of persons on board
  • Any other useful information (fuel remaining, endurance, weather)

Key behaviours

  • Silence on the frequency: once a distress call is transmitted, all other stations must stop transmitting and maintain radio silence unless helping.
  • Squawk 7700 on the transponder for a general emergency (7600 for radio failure, 7500 for unlawful interference - hijack).
  • You do not need a licence or authority from anyone to declare an emergency - as PIC you decide, and safety always comes first.
  • Cancelling: once the emergency is over, transmit a message cancelling the distress or urgency condition on the same frequency, so ATC and other traffic know you are safe.
  • Any station receiving a MAYDAY must acknowledge it and assist if able; if ATC does not respond, any other pilot should.

Common mistakes to avoid

  • Saying MAYDAY only once - it must be said three times to avoid confusion with normal speech.
  • Using PAN PAN when the situation is actually grave and imminent (should be MAYDAY).
  • Forgetting to give position and persons on board - these are the details rescuers need most.
  • Wasting time retuning to 121.5 when your current frequency already has a listening station.
  • MAYDAY is used for grave and imminent danger requiring immediate assistance, said three times: MAYDAY MAYDAY MAYDAY.
  • PAN PAN is used for an urgency condition not requiring immediate assistance, said three times: PAN PAN PAN PAN PAN PAN.
  • 121.5 MHz is the international VHF emergency (guard) frequency, used if your current frequency gets no response.
  • The distress message order is: MAYDAY x3, station called, callsign, aircraft type, nature of emergency, intentions, position/level/heading, persons on board, other useful info.
  • Squawk 7700 for a general emergency, 7600 for radio failure, and 7500 for unlawful interference (hijack).
  • Try your current working frequency first before switching to 121.5 - do not waste time retuning unnecessarily.
  • Once a MAYDAY is transmitted, all other stations must observe radio silence unless assisting.
  • As pilot in command, you need no permission to declare an emergency - the decision is yours alone.
  • Always cancel a MAYDAY or PAN PAN once the emergency is resolved, transmitted on the same frequency used for the original call.
  • Number of persons on board and present position are critical details rescuers need and must not be omitted.
  • Any station receiving a distress message must acknowledge it; if ATC cannot respond, another pilot should.
  • Fuel remaining and endurance are useful additional information to include after the core distress message elements.
How many times is MAYDAY said in a distress call, and why?
Three times (MAYDAY MAYDAY MAYDAY), to make it unmistakable and distinct from normal speech.
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What is the difference between MAYDAY and PAN PAN?
MAYDAY = grave and imminent danger needing immediate assistance. PAN PAN = urgency condition, safety concern, but not requiring immediate assistance.
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Which frequency should you try first in an emergency?
Your current working frequency - only switch to 121.5 MHz if that gets no response or you are not already in contact with anyone.
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What is 121.5 MHz?
The international VHF emergency (guard) frequency, monitored by ATC units and many aircraft.
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List the elements of a distress message in order.
MAYDAY x3, station called, callsign, aircraft type, nature of emergency, intentions, position/level/heading, persons on board, other useful info.
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What transponder code is used for a general emergency?
Squawk 7700.
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What transponder code is used for radio failure?
Squawk 7600.
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What transponder code is used for unlawful interference (hijack)?
Squawk 7500.
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Who decides whether to declare a MAYDAY?
The pilot in command - no permission or authority from anyone else is needed.
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What must other stations do once a MAYDAY is transmitted?
Maintain radio silence on that frequency unless they are assisting with the emergency.
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What should you do once the emergency situation is over?
Transmit a message cancelling the distress or urgency condition on the same frequency used for the original call.
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What two pieces of information do rescuers need most from a distress call?
Present position and number of persons on board.
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Give an example of when to use PAN PAN rather than MAYDAY.
Being lost, low on fuel, having a minor technical issue, or an unwell passenger - situations that are urgent but not immediately life-threatening.
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What should happen if ATC does not respond to a MAYDAY call?
Any other pilot who hears it should acknowledge and assist if able.
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What is a common mistake with the PAN PAN call?
Using it when the situation is actually grave and imminent, when MAYDAY should have been used instead.
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Equipment & frequencies

VHF radio: the basics

UK aviation radio uses VHF (Very High Frequency) between 118.000 MHz and 136.975 MHz. VHF travels line of sight only - no bending round hills or the earth's curvature, so range depends on your height and the height of the station you're calling.

Channel spacing

Most UK aerodromes now use 8.33 kHz channel spacing (introduced to fit more frequencies into the band). Some services still use the older 25 kHz spacing. Your radio must be 8.33 kHz capable to operate below FL195 in most UK airspace - check the aircraft's radio fit before you fly.

Key frequencies to know cold

  • 121.5 MHz - the international emergency and distress frequency, also called Guard. Every radio should be able to receive it even when tuned elsewhere.
  • 123.45 MHz - the air-to-air chat frequency, useful over the sea or outside controlled airspace when no ATSU is available.
  • 130.500/130.480/135.475 MHz - Volmet and similar broadcasts giving recorded weather for major airports (varies by service).
  • Aerodrome ATIS (Automatic Terminal Information Service) - a recorded loop of runway-in-use, weather and QNH, broadcast on its own published frequency so you don't clog up Tower asking for it.

Types of ground station

  • Tower - controls the runway and circuit.
  • Ground/Apron - controls taxiways and parking.
  • Approach/Radar - controls aircraft joining or leaving controlled airspace.
  • AFIS (Aerodrome Flight Information Service) - an AFISO gives information, not instructions, at smaller airfields.
  • FIS (Flight Information Service) - similar advisory service from an area controller, e.g. London Information on 124.750 MHz.

Transponders and squawk codes

A transponder sends your aircraft's identity and altitude to radar (Mode A/C or Mode S). Standard conspicuity squawk in the UK is 7000 unless told otherwise. Three codes are reserved worldwide and must never be used except for their real purpose:

  • 7500 - unlawful interference (hijack)
  • 7600 - radio failure
  • 7700 - general emergency

Common mistakes

Students often mix up 121.5 (emergency voice) with 7700 (emergency squawk) - they're two separate systems, transmitted together in a real emergency. Also watch for confusing ATIS (recorded, one-way, no readback) with a live controller (two-way, needs readback). Finally, remember VHF range is limited by line of sight - flying low behind high ground will cut you off even if you're geographically close to the station.

  • VHF aviation band runs from 118.000 MHz to 136.975 MHz
  • 121.5 MHz is the international emergency/distress and Guard frequency
  • Standard UK conspicuity squawk is 7000 unless instructed otherwise
  • 7500 squawk means unlawful interference (hijack) - never test it
  • 7600 squawk means radio failure
  • 7700 squawk means general emergency
  • Most UK stations now use 8.33 kHz channel spacing, older ones use 25 kHz
  • VHF signals travel by line of sight only, so range depends on altitude, not distance over the ground
  • ATIS gives a recorded, one-way broadcast of runway, weather and QNH - no readback needed
  • AFIS provides information only, from an AFISO, not control instructions
  • 123.45 MHz is the informal air-to-air chat frequency
  • London Information (FIS) broadcasts on 124.750 MHz
What is the VHF aviation frequency band in the UK?
118.000 MHz to 136.975 MHz
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What frequency is the international emergency/distress (Guard) frequency?
121.5 MHz
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What is the standard UK conspicuity squawk code?
7000, unless a controller assigns a different code
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What does squawk 7500 mean?
Unlawful interference (hijack) - reserved, never use for testing
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What does squawk 7600 mean?
Radio communication failure
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What does squawk 7700 mean?
General emergency
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What channel spacing do most UK stations now use?
8.33 kHz (replacing the older 25 kHz spacing)
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Why is VHF range limited even in clear conditions?
VHF travels line of sight only, so range depends on the height of aircraft and station, not distance over the ground
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What does ATIS provide and how do you respond to it?
A recorded one-way broadcast of runway-in-use, weather and QNH - you listen and note it, no readback is given
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What is the difference between Tower and Ground/Apron frequencies?
Tower controls the runway and circuit; Ground/Apron controls taxiways and parking
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What does AFIS stand for and what can an AFISO give you?
Aerodrome Flight Information Service - information only, not control instructions
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What is 123.45 MHz used for?
Informal air-to-air chat between aircraft, useful over the sea or outside controlled airspace
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What frequency does London Information (FIS) broadcast on?
124.750 MHz
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Do you need an 8.33 kHz capable radio to operate below FL195 in most UK airspace?
Yes - most UK airspace below FL195 requires 8.33 kHz capability
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What kind of broadcasts give recorded weather for major airports?
Volmet broadcasts, on frequencies such as 130.500 MHz
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