Communications

What are the rules of talking on the radio?

The big picture

Four areas. Tap a box with + to open it; hover a word for its meaning.

• Radiotelephony Annex 10, Doc 4444 How to speak on the radio: numbers and standard words, call signs, weather terms, and the radio waves and data links that carry it.
  • Saying it right numbers, words, read-back Standard ways to transmit flight levels, frequencies and time, the key phrases and their fixed meanings, and what must be read back.
    • Flight levels FLIGHT LEVEL + each digit Say FLIGHT LEVEL, then each digit separately: FL 180 is flight level one eight zero.
    • Frequencies digits + DECIMAL Say each digit, with DECIMAL for the point: 128.3 MHz is one two eight decimal three.
    • Time minutes normally, always UTC Add the hour if there could be confusion. Time checks go to the nearest half minute.
    • Key words ROGER, STANDBY, IMMEDIATE Standard words with fixed meanings. ROGER, STANDBY and CLEARED FOR IMMEDIATE TAKE OFF are the ones most easily misused.
      • ROGER received, nothing more Never use ROGER to answer a yes/no question.
      • STANDBY wait; not yes or no Wait, I will call you back. If the wait is long, the caller usually calls again. It is neither a yes nor a no.
      • CLEARED FOR IMMEDIATE TAKE OFF line up and go without stopping Taxi onto the runway at once and start the take-off without stopping.
    • What you read back QNH always Safety-related parts of voice clearances and instructions are read back, and QNH always. Other items may be acknowledged with the call sign.
      • Route clearances An ATC route clearance must always be read back.
      • Runway clearances enter, land, take off, cross... Going onto, landing on, taking off from, holding short of, crossing, taxiing on or backtracking along any runway.
      • Settings and numbers QNH, squawk, level, heading, speed Also the runway in use, other altimeter settings and the transition level.
  • Call signs ground units and aircraft Each ground unit has a call sign suffix for the service it gives. Aircraft call signs come in three types, two of which may be shortened.
    • Area control centre CONTROL The area control centre uses the call sign suffix CONTROL.
    • Approach and aerodrome APPROACH, TOWER Approach control uses the suffix APPROACH; aerodrome control uses TOWER.
    • Surface movement, clearance GROUND, DELIVERY Surface movement control uses the suffix GROUND; clearance delivery uses DELIVERY.
    • Other units RADAR, APRON, INFORMATION, RADIO... Also PRECISION, HOMER, DISPATCH, FLOW, UPPER/LOWER CONTROL, APPROACH RADAR and CONTROL RADAR.
    • Aircraft call signs when they may be shortened Registration, designator plus registration, or designator plus flight number. Shorten only after good contact is made and no confusion is likely.
      • Registration: VTEJP short form VJP First character plus at least the last two.
      • Designator + registration AIRINDIA TEJP becomes AIRINDIA JP Designator plus at least the last two characters.
      • Designator + flight number AIRINDIA 809: never shortened The operator's telephony designator plus the flight identification, such as AIRINDIA 809. It has no abbreviated form.
  • Weather by radio reports and broadcasts Weather reaches the pilot from ATC, met offices, ATIS and VOLMET as reports, forecasts and warnings.
    • METAR / SPECI routine and special reports METAR is the aviation routine weather report; SPECI is the aviation selected special weather report.
    • TREND / TAF next 2 hours; aerodrome forecast TREND gives the changes expected in the next two hours; TAF is the aerodrome forecast.
    • SIGMET / AIRMET all aircraft; low-level flights Both come from a meteorological watch office about en-route weather. SIGMET concerns all aircraft; AIRMET concerns low-level flights, adding what the low-level forecast missed.
    • ATIS / VOLMET also by data link ATIS is a continuous, repetitive broadcast for the terminal aerodrome. VOLMET broadcasts aerodrome reports on HF. Both also come by data link.
    • Cloud amounts FEW 1-2, SCT 3-4, BKN 5-7, OVC 8 Cloud amounts are in octas: few is 1-2, scattered 3 or 4, broken 5-7 and overcast 8.
  • Radio waves and data link bands and range The frequency bands, how radio waves travel to the receiver, and the data link systems that supplement voice.
    • HF 3-30 MHz; comms use 2-25 MHz High Frequency, 3 to 30 MHz. Part of HF is reflected back from the ionosphere as sky wave, giving long range. HF communications use 2 to 25 MHz.
    • VHF 30-300 MHz; comms use 118-137 MHz Line of sight. Range (NM) = 1.25 x (root of transmitter height + root of receiver height), heights in feet. VOR uses 108.0 to 117.95 MHz.
    • Each band is ten times the last VLF, LF, MF, HF, VHF, UHF, SHF, EHF From VLF (3-30 kHz) up to EHF (30-300 GHz), each band covers frequencies ten times higher than the band before it.
    • CPDLC text messages, non-urgent Used beyond VHF range. It supplements voice.
    • ADS automatic position reports Log on 10 minutes before entering the FIR.

Takeaway: Say numbers and words the standard way, read back what matters, use the right call sign, and know the weather broadcasts and radio bands.

Which message first, which Q-code, how readable?

Radio habits

Three views: message priority, the Q-codes and the readability scale.

Radiotelephony runs on fixed orders and short codes so that a crowded frequency still works.

• Radiotelephony runs on fixed orders and short codes so that a crowded frequency still works.
• Priority
• Whose message goes first?
• Six kinds of message, from the highest priority to the lowest. Drag the slider or tap a bar.
• First
• Last
• Distress
• MAYDAY calls and traffic
• Anything to do with distress (the call, the message and the traffic that follows) always comes first.
• Urgency
• PAN PAN, PAN PAN MEDICAL, SECURITE
• Urgency messages, including PAN PAN MEDICAL for medical transport, and SECURITE, SECURITE, SECURITE.
• Direction finding
• DF communications
• Communications relating to direction finding.
• Flight safety
• flight safety messages
• Flight safety messages come fourth.
• Meteorological
• weather messages
• Meteorological messages come fifth.
• Flight regularity
• lowest priority
• Flight regularity messages come last of the six.
• Q-codes
• Three letters, one question
• Bearings first: to or from the station, magnetic or true. Then the rest. Tap a row.
• QDM
• Magnetic bearing to the station
• Magnetic bearing to the station. For any bearing, ask two things: to the station or from it, and magnetic or true?
• QUJ
• True bearing to the station
• True bearing to the station. For any bearing, ask two things: to the station or from it, and magnetic or true?
• QDR
• Magnetic bearing from the station
• Magnetic bearing from the station. For any bearing, ask two things: to the station or from it, and magnetic or true?
• QTE
• True bearing from the station
• True bearing from the station. For any bearing, ask two things: to the station or from it, and magnetic or true?
• QNH
• Altimeter reads elevation on the ground
• When given in inches, INS is said.
• QFE
• Altimeter reads height above the aerodrome
• With this setting the altimeter reads height above aerodrome elevation, or above the threshold.
• QNE
• Altimeter reading on landing with 1013.2 set
• Altimeter reading on landing with 1013.2 set.
• QFU
• Runway number, or its magnetic direction
• Runway number is two figures; magnetic direction is three.
• QGH
• May I land using this procedure or aid?
• May I land using this procedure or aid?.
• QDL
• I intend to ask for a series of bearings
• I intend to ask for a series of bearings.
• Readability
• How do you read me?
• A radio check is answered on a scale of 1 to 5. Drag along it.
• unreadable
• perfect
• Readability 1
• Unreadable
• Readability 1 unreadable, 2 now and then, 3 with difficulty, 4 readable, 5 perfectly readable.
• Readability 2
• Readable now and then
• Readability 3
• Readable with difficulty
• Readability 4
• Readable
• Readability 5
• Perfectly readable

Takeaway: Distress, urgency, direction finding, flight safety, weather, regularity. QDM to the station, QDR from it. Readability 1 to 5.

How do you say numbers on the radio?

Say it right

Written, then spoken. Read across each row.

This lesson is part of the Exam-Ready plan. See plans

What does each standard phrase mean?

Standard words

Each bubble is the meaning; the name is the phrase. Hide the names and test yourself.

This lesson is part of the Exam-Ready plan. See plans

Must you read it back?

Read back?

Test the message against the read-back list. One yes is enough.

This lesson is part of the Core plan. See plans

When may you change frequency?

Change frequency?

Read each case and press the stamp that applies.

This lesson is part of the Exam-Ready plan. See plans

Which Q-code gives which bearing?

Q bearings

Ask two things: to the station or from it, and magnetic or true?

This lesson is part of the Core plan. See plans

What do the other Q-codes mean?

Other Q-codes

Three altimeter settings, two about the runway and approach, and one about bearings.

This lesson is part of the Core plan. See plans

What goes into a position report, and in what order?

Position report

Six items, always in the same order.

This lesson is part of the Core plan. See plans

How is traffic information given?

Traffic info

You are in the centre. Tap each number.

This lesson is part of the Exam-Ready plan. See plans

What does radar identification and vectoring mean for you?

Radar service

Identification, service, vectors and levels. Tap + to open each.

This lesson is part of the Exam-Ready plan. See plans

Where does weather come from on the radio?

Weather sources

Reports, broadcasts and what you send back. Tap + to open each.

This lesson is part of the Exam-Ready plan. See plans

How do you decode a METAR and TREND?

Read a METAR

Delhi, the book's example. Tap each group.

This lesson is part of the Exam-Ready plan. See plans

How do you send an AIRREP SPECIAL?

AIRREP SPECIAL

The model format, section by section.

This lesson is part of the Exam-Ready plan. See plans

What do braking action terms mean?

Braking action

Six terms, best to worst.

This lesson is part of the Exam-Ready plan. See plans

What is a radio wave?

Radio waves

One wave, how it travels, and how far it goes. Tap each number.

This lesson is part of the Exam-Ready plan. See plans

Which band does each system use?

Which band?

Bars on a log scale: each step is ten times the frequency. Tap a bar.

This lesson is part of the Exam-Ready plan. See plans

How do CPDLC, ADS and SATCOM work in India?

Data link and SATCOM

Channels, data link, satellites and performance. Tap + to open each.

This lesson is part of the Exam-Ready plan. See plans

Numbers to know

Numbers

Distress frequencies, squawks and weather limits in one list.

This lesson is part of the Core plan. See plans

Pairs that catch students out

Don't mix up

Each pair looks alike. The rule underneath tells them apart.

This lesson is part of the Core plan. See plans

Test yourself

Ten questions from this chapter.

This lesson is part of the Core plan. See plans