IFR communication

The subject IFR communication provides the knowledge and skills required to ensure clear, precise and compliant communication in instrument flight operations. Radio communication is the backbone of co-operation between air and ground radio stations and contributes significantly to the safety and efficiency of air traffic. This article provides an overview of the content of the subject.

Radio communication

1. definition and terms

• Radio communication:
  • Exchange of information via electromagnetic waves between aircraft and ground stations.
  • The aim is to ensure clear and unambiguous instructions in order to minimise risks.
• Terms:
  • ATC (Air Traffic Control): Air traffic control, which is responsible for controlling and securing air traffic.
  • Station: General term for a radio station, be it a ground station or an aircraft.

2. communication method

• Transfer of numbers and letters:
  • Figures:
    • Numbers are pronounced individually, e.g. 123 as "one-two-three".
    • Decimal numbers are emphasised with "decimal" or "comma": e.g. "one-two-three decimal four".
  • Letters:
    • The ICAO alphabet is used to avoid misunderstandings. Examples:
      • "Alpha" for A
      • "Bravo" for B
      • "Charlie" for C
• Callsign:
  • Aircraft: Consists of the aircraft registration (e.g. "Delta-Echo-Lima-Kilo-Alpha") or the flight number.
  • Ground stations: Named after their function, e.g. "Tower" (airport tower), "Ground" (ground traffic) or "Approach" (approach control).
• Establish the radiotelephone connection:
  • A radio message is initiated by stating the station addressed and your own callsign. Example: "Munich Tower, Delta-Echo-Lima-Kilo-Alpha, ready for departure holding point runway 31".
  • Standardised procedures ensure clear and efficient communication.
• Confirmation of messages:
  • Information is repeated by the recipient to avoid misunderstandings. This is known as "readback".

3. emergency and urgent transport

• Emergency traffic (MAYDAY):
  • Used when there is immediate danger to the aircraft or life.
  • Structure of an emergency call:
    • Three repetitions of "MAYDAY".
    • Callsign of the aircraft.
    • Type of emergency and assistance required.
    • Example: "MAYDAY, MAYDAY, MAYDAY, Delta-Echo-Lima-Kilo-Alpha, engine failure, emergency landing required."
• Urgent traffic (PAN-PAN):
  • Used when there is no immediate danger but help is urgently needed.
    • Example: "PAN-PAN, PAN-PAN, PAN-PAN, Delta-Echo-Lima-Kilo-Alpha, medical emergency on board."

4. radio failure and blind transmissions

• Radio failure:
  • Procedure for VMC (Visual Meteorological Conditions):
    • If the radio failure occurs in VMC, the pilot remains in visual flight and lands at the nearest suitable airport and then informs ATC.
    • ATC must be informed of the situation by transponder code (7600).
  • Procedure for IMC (Instrument Meteorological Conditions):
    • Hold the last instructed altitude or the Minimum Enroute Altitude (MEA), whichever is higher, and the last assigned speed for 7 minutes.
    • The pilot then continues the flight according to the approved flight plan.
    • If an approach is planned, the pilot will begin the approach at the scheduled time and land at the destination airport or at the alternative airport if necessary.
    • The transponder code 7600 signals the radio failure to ATC.
• Blind programmes:
  • Information is sent out even if no confirmation is received. Example: "Delta-Echo-Lima-Kilo-Alpha, flying FL100, position over DINKA at 12:30."

Weather information

1 METAR

• Definition:
  • Regular weather reports from aerodromes.
  • Contents:
    • Wind direction and strength.
    • Visibility and weather phenomena.
    • Cloud formations.
    • Temperature and dew point.
    • Air pressure (QNH).

2ND TAF

• Definition:
  • Terminal Aerodrome Forecast (TAF) provides weather forecasts for aerodromes.
  • Example: "TAF EDDM 121400Z 1218/1318 27012KT 9999 FEW030 BKN080."

3 GAFOR (General Aviation Forecast)

• Purpose:
  • Provides regional weather forecasts for visual flights and shows restrictions such as poor visibility or low cloud bases.

4. SIGMET and AIRMET

• SIGMET:
  • Warnings of significant weather phenomena such as thunderstorms, strong turbulence or ash clouds.
• AIRMET:
  • Information about light turbulence, clouds or light icing.

5 VOLMET and ATIS

• VOLMET:
  • Weather reports for aircraft en route, transmitted in real time.
• ATIS (Automatic Terminal Information Service):
  • Automated information on weather, active runways and special instructions for arriving and departing aircraft.

Wave and signal propagation

1. radio waves

• Properties:
  • The frequency determines the wavelength, range and reflectivity.
  • VHF frequencies are used for aeronautical radio because they offer good range and low susceptibility to interference.
• Types of propagation:
  • Direct waves: Utilise the line of sight between transmitter and receiver, e.g. for VOR.
  • Bumps in the road: Track the curvature of the earth, often on long waves.
  • Ionospheric waves: Enable reflections for long-distance connections.

2. radar

• Basics:
  • Radar uses reflected electromagnetic waves to locate objects.
• Secondary radar (SSR):
  • Identifies aircraft using transponders and provides altitude and position data.

Conclusion

The subject IFR communication provides knowledge to organise communication in instrument flight safely and efficiently. Clear communication procedures, dealing with emergency situations and the use of meteorological information form the foundation for smooth flight operations. Comprehensive training in this area is essential to ensure both the safety and efficiency of air traffic.

---

Source references:
EASA FCL