L7 Communications Failure

Communications Failure

Actions in the Event of Communication Failure

• Loss of voice communications does not affect aircraft performance in Visual Meteorological Conditions (VMC).

• However, it may limit airfield and airspace choices.

• Integrating with traffic becomes more complex, especially at airfields where radio is commonly used.

Non-Radio Flight Requirements

• Before considering non-radio flight, troubleshoot the communication loss.

Initial Troubleshooting Steps:

• Frequency Checks:

  • Verify the correct frequency is selected.

  • Confirm frequency is within operational hours and range of the ground station.

  • Listen for other transmissions on the frequency.

  • Try an alternative or previous frequency.

• Radio Control Checks:

  • Check the volume.

  • Ensure the frequency is set to 'active'.

  • Try a second radio if available.

• Audio Controller Checks:

  • Verify audio controller settings for your seat (left or right).

  • Check intercom settings (volume, on/off).

• Headset Checks:

  • Check headset volume controls.

  • Ensure the headset is fully plugged in.

  • If applicable, check headset power (batteries).

  • For wireless headsets, check all system elements.

  • Test headset in alternative sockets in the cockpit if available, and use an alternative headset for testing.

• Avionics Master Switch:

  • Confirm the Avionics Master Switch hasn't been accidentally turned off.

• Wider Electrical Problem:

  • Assess for a broader electrical failure.

Pilot Priorities and Establishing Contact

• Prioritize:

  • Aviate

  • Navigate

  • Communicate

• Flying the aircraft and navigation are paramount while troubleshooting communications.

• Consider alternative contact methods:

  • Hand-Held Radio:

    • Use as a backup if accessible.

    • Note that it has less power and range than the aircraft's radio.

    • A headset is desirable due to cockpit noise.

  • Mobile Phone:

    • Use may be helpful in emergencies, despite being discouraged normally.

    • Cockpit noise can make phone conversations difficult.

    • Signal strength depends on altitude and terrain.

• Reiterate: Aviate, Navigate, Communicate.

Actions to Take After Communications Failure

• Assess the situation after confirming communications failure.

• If the flight only involves airspace where radio is not required, the loss may be a minor issue.

• A change of plan may be needed.

• Take stock of the situation, considering:

  • Remaining fuel/range/endurance.

  • Remaining daylight.

  • Weather considerations.

  • Whether the radio failure is part of a wider failure (e.g., electrical).

• General Guidelines:

  • Remain in VMC if possible.

  • Plan to land before sunset if possible.

  • Use the radio failure squawk (7600) if the transponder is operating.

  • Avoid controlled airspace without permission.

  • Avoid Radio Mandatory Zones (RMZ) unless safety requires it.

  • Select an airfield outside controlled airspace if possible.

  • Be extra vigilant for other traffic, as they may not expect you.

  • Be prepared to give way to other traffic.

Blind Transmission Calls

• If you suspect your radio is transmitting but not receiving, make radio calls on normal frequencies.

• State your situation, position, and intentions.

• Prefix each call with "transmitting blind".

• ICAO definition: Transmission from one station to another when two-way communication isn't possible, but the called station is believed to be receiving.

Radio Transmission Calls

• If the radio is receiving but only transmitting a carrier wave, use the Speechless Code.

• The Speechless Code involves short presses of the 'Press To Talk' (PTT) button:

  • One short dash: Yes

  • Two short dashes: No

  • Three short dashes: Say Again

  • Four short dashes: Request Homing (heading to airfield) or Request Assistance

• Avoid double-clicking the PTT button in response to transmissions, as it is non-standard and may be misinterpreted.

Arrival at Airfield Following Communications Failure

• The Air Traffic Service Unit (ATSU) may use light signals.

• Light signals might only be visible up to one nautical mile in good conditions. *Factors affecting visibility:

  • Bright Sunlight

  • Filters

  • Tinted windows

• If expecting light signals, position on the 'dead side' of the circuit, close to the tower at circuit altitude/height.

• Look carefully for light signals from the ATSU.

Ground to Air Light Signals:

• Steady green: Cleared to land

• Steady red: Give way to other aircraft and continue circling

• Series of green flashes: Return for landing

• Series of red flashes: Aerodrome unsafe, do not land

• Series of white flashes: Land at this aerodrome and proceed to apron

Light Signals to an Aircraft on the Ground:

• Steady green: Cleared for take-off

• Steady red: Stop

• Series of green flashes: Cleared to taxi

• Series of red flashes: Taxi clear of landing area in use

• Series of white flashes: Return to starting point on the aerodrome

Non-Radio Signals

Aircraft in Flight:

• I acknowledge your light signal: Rock aircraft's wings (daylight only, not used on base leg or final approach)

  • Flash aircraft's landing lights twice (night-time only), or switch navigation lights on and off twice if not equipped.

Aircraft on Ground:

• I acknowledge your light signal: Move the aircraft's ailerons or rudder (daylight only)

  • Flash aircraft's landing lights twice (night-time only), or switch navigation lights on and off twice if not equipped.

Standard Phraseology

• How do you read?: What is the readability of my transmission?

• I say again: I repeat for emphasis or clarity

• Say again: Repeat all, or a specified part, of your last transmission

• Speak slower: Reduce your rate of speech

• Words twice (as a request): Communication is difficult, transmit every word, or group of words, twice

• Words twice (as information): Because communications are difficult, every word, or group of words, in this message will be transmitted twice

• Use these phrases to avoid confusion or uncertainty: If in doubt, shout.