During Bournemouth Conference SC 1 tasked ANACNA to collect and collate R/F procedures from all Ma’s and ICAO to further develop policy , particularly in reference to planned higher levels.

Basic Reference

Collection and comparison methods have been chosen in order to comply with the following aspects :

• The existence of IFATCA policy concerning this subject or regarding with it :
  • R/F communication failure: Page 3244 IFATCA Manual;
  • Frequency blocking: Page 3247 IFATCA Manual;
  • Traffic Information Broadcast by Aircraft: Page 3248 IFATCA Manual.
• The need to specify a simple and clear procedure of comparison with regard to a numberless amount of data, without compromising the aim of the research.

Survey Method

Phase 1 – It was necessary to specify prominent variable factors that may be the basis for any R/F procedure (for instance : flight rules, phase of flight, weather conditions, airspace classification and structure etc.)

Following variables have been considered prominent :

• Variable ‘STATION’
  • Radio failure events can equally concern both ground stations and in flight stations.
• Variable ‘ACTION’
  • Any regulation shall clearly establish pilot and control action during ground or board radio failure.

Variable 1 – TYPE OF RADIO FAILURE

There are three possibilities : complete, only receiver and only transmitter radio failure.

Variable 2 – AVAILABILITY OF ALTERNATIVE MEANS OF COMMUNICATION

A radio failure may not be a real problem, if alternative means of communication are able to maintain a continuous two – way connection. No problems arise if AMSS , Mode S, VHF data link are available. Other alternative means of communication, such as visual signals, use of primary or secondary radar and navigational or approach aids, cannot grant a continuous two – way. In these cases flight operations should be modified with reference to the level of existing communication.

Variable 3 – METEOROLOGICAL CONDITIONS

Pilot obligations are different according to VMC or IMC conditions.

Variable 4 – FLIGHT RULES

IFR / Special VFR.

Variable 5 – ATS SERVICE PROVIDED TO THE AIRCRAFT

Uncontrolled flight or controlled flight.

Variable 6 – PHASE OF FLIGHT

Risks related to radio failure have a different impact according to phase of flights. The following phases have been identified (only to meet survey needs):

Ground movement: Taxing

In flight phases: Departure; En-route; Approach; Landing

Variable 7 – MINIMISE DELAYS

Among radio-failure procedures having the same safety level, the most efficient shall be chosen:

Phase 2 – the following results have been reached :

• ICAO standards do not prescribe radio failure rules according to flight rules (IFR – VFR Special VFR);
• A problem of interpretation may arise comparing Annex and Doc 4444. According to Annex 2 a separation shall be only applied if aircraft continues its IMC flight. According to Doc 4444 a separation shall be always applied;
• As transmitter radio failure cannot actually grant a continuous two-way, controllers and pilot obligations are not clearly defined.

Phase 3 – MA’s have been asked to send all the rules concerning R/F and to file a very brief questionnaire.

Phase 4 – National rules of every MA’s will be compared with ICAO standards specifying the differences for each variable factor. A ‘score’ will be assigned to each difference. This ‘score’ will mean only the degree of difference from ICAO standards. A quality survey will also be done in order to point out the best solutions.

Phase 5 – Based on the documentation collected and collated we will be able to specify :

• Percentage of MA’s that adhere to ICAO standards;
• Percentage of MA’s that have a good deal of local R/F procedures;
• Percentage of differences for a single variable factor;
• Procedures that seem to better regulate R/F events.