3 UNLAWFUL INTERFERENCE

NOTE: None of the provisions in this section shall prevent the use, by an aircraft in distress, of any means at its disposal to attract attention, make known its position and obtain help.

2.5.1Distress Signals

d.rockets or shells throwing red lights, fired one at a time at short intervals;

e.a parachute flare showing a red light.

(Annex 2, Appendix 1, 1.1)

2.5.2Urgency Signals

2.5.2.1 The following signals, used either together or separately, mean that an aircraft wishes to give notice of difficulties which compel it to land without requiring immediate assistance:

a.the repeated switching on and off of the landing lights; or

b.the repeated switching on and off of the navigation lights in such a manner as to be distinct from flashing navigation lights.

(Annex 2, Appendix 1, 1.2.1)

2.5.2.2 The following signals, used either together or separately, mean that an aircraft has a very urgent message to transmit concerning the safety of a ship, aircraft or other vehicle, or of some person on board or within sight;

a.a signal made by radiotelegraphy or by any other signalling method consisting of the group XXX;

b.a radiotelephony urgency signal consisting of the spoken words PAN, PAN.

c.an urgency message sent via data link which transmits the intent of the words PAN, PAN.

(Annex 2, Appendix 1, 1.2.2)

communications from the aircraft involved and it is certain that such reference will not aggravate the situation. (Annex 11, 5.6.2)

3.2TRANSPONDER OPERATIONS — UNLAWFUL INTERFERENCE WITH AIRCRAFT IN FLIGHT

3.2.1Should an aircraft in flight be subjected to unlawful interference, the pilot-in-command shall endeavor to set the transponder to Mode A Code 7500 to give indication of the situation unless circumstances warrant the use of Code 7700. (Doc 8168, Vol I, Part VIII, 1.6.1)

3.2.2When a pilot has selected Mode A Code 7500 and is subsequently requested to confirm the code by ATC he/she shall, according to circumstances, either confirm this or not reply at all. (Doc 8168, Vol I, Part VIII, 1.6.2)

NOTE: The absence of a reply from the pilot will be taken by ATC as an indication that the use of Code 7500 is not due to an inadvertent false code selection.

3.3PROCEDURES

3.3.1The following procedures are intended as guidance for use by aircraft when unlawful interference occurs and the aircraft is unable to notify an ATS unit of this fact. (Annex 2, Attachment B)

3.3.2Unless considerations aboard the aircraft dictate otherwise, the pilot-in-command should attempt to continue flying on the assigned track and at the assigned cruising level at least until able to notify an ATS unit or within radar coverage. (Annex 2, Attachment B, 2.1)

3.3.3When an aircraft subjected to an act of unlawful interference must depart from its assigned track or its assigned cruising level without being able to make radiotelephony contact with ATS, the pi- lot-in-command should, whenever possible;

a.attempt to broadcast warnings on the VHF emergency frequency and other appropriate frequencies, unless considerations aboard the aircraft dictate otherwise. Other equipment such as on-board transponders, data links, etc., should also be used when it is advantageous to do so and circumstances permit; and

b.proceed in accordance with applicable special procedures for in-flight contingencies, where such procedures have been established and promulgated in ICAO Document 7030 — Regional Supplementary Procedures; or

c.if no applicable regional procedures have been established, proceed at a level which differs from the cruising levels normally used for IFR flight by:

1.150m (500 ft) in an area where a vertical separation minimum of 300m (1000 ft) is applied; or

2.300m (1000 ft) in an area where a vertical separation minimum of 600m (2000 ft) is applied.

(Annex 2, Attachment B, 2.2)

tress and urgency signals. (Annex 10, Vol II, 5.3.1.2.1)

5.1.2The originator of messages addressed to an aircraft in distress or urgency condition shall restrict to the minimum the number and volume and content of such messages as required by the condition. (Annex 10, Vol II, 5.3.1.3)

5.1.3If no acknowledgement of the distress or urgency message is made by the station addressed by the aircraft, other stations shall render assistance, as prescribed in 5.2.2 and 5.3.2 respectively.

(Annex 10, Vol II, 5.3.1.4)

NOTE: “Other stations” is intended to refer to any other station which has received the distress or urgency message and has become aware that it has not been acknowledged by the station addressed.

4 EMERGENCY DESCENT

4.1INITIAL ACTION BY THE AIR TRAFFIC CONTROL UNIT

4.1.1 Upon receipt of advice that an aircraft is making an emergency descent through other traffic, all possible action shall be taken immediately to safeguard all aircraft concerned. When deemed necessary, air traffic control units shall immediately broadcast by means of the appropriate radio aids, or if not possible, request the appropriate communications stations immediately to broadcast an emergency message. (Doc 4444, Part III, 15.1.4)

4.2ACTION BY THE PILOT-IN-COMMAND

4.2.1 It is expected that aircraft receiving such a broadcast will clear the specified areas and standby on the appropriate radio frequency for further clearances from the air traffic control unit. (Doc 4444 Part III, 15.1.4)

4.3SUBSEQUENT ACTION BY THE AIR TRAFFIC CONTROL UNIT

4.3.1 Immediately after such an emergency broadcast has been made the area control center, the approach control office, or the aerodrome control tower concerned shall forward further clearances to all aircraft involved as to additional procedures to be followed during and subsequent to the emergency descent. The ATS unit concerned shall additionally inform any other ATS units and control sectors which may be affected. (Doc 4444, Part III, 15.1.4)

5DISTRESS AND URGENCY RADIOTELEPHONY COMMUNICATION PROCEDURES

5.1GENERAL

5.1.1 The radiotelephony distress signal MAYDAY and the radiotelephony urgency signal PAN PAN shall be used at the commencement of the first distress and urgency communication respectively.

(Annex 10, Vol II, 5.3.1.2)

5.1.1.1 At the commencement of any subsequent communication in distress and urgency traffic, it shall be permissible to use the radiotelephony dis-

5.1.4 Distress and urgency traffic shall normally be maintained on the frequency on which such traffic was initiated until it is considered that better assistance can be provided by transferring that traffic to another frequency. (Annex 10, Vol II, 5.3.1.5)

NOTE: 121.5 MHz or alternative available VHF or HF frequencies may be used as appropriate.

5.1.5 In cases of distress and urgency communications, in general, the transmissions by radiotelephony shall be made slowly and distinctly, each word being clearly pronounced to facilitate transcription.

(Annex 10, Vol II, 5.3.1.6)

5.2RADIOTELEPHONY DISTRESS COMMUNICATIONS

5.2.1Action by the Aircraft in Distress

5.2.1.1 In addition to being preceded by the radiotelephony distress signal MAYDAY, preferably spoken three times, the distress message to be sent by an aircraft in distress shall:

a.be on the air-ground frequency in use at the time;

b.consist of as many as possible of the following elements spoken distinctly and, if possible, in the following order:

1.name of the station addressed (time and circumstances permitting);

2.the identification of the aircraft;

3.the nature of the distress condition;

4.intention of the person in command;

5.present position, level (i.e., flight level, altitude, etc., as appropriate) and heading.

(Annex 10, Vol II, 5.3.2.1.1)

NOTE:

1. The foregoing provisions may be supplemented by the following measures;

a. the distress message of an aircraft in distress being made on the emergency frequency 121.5 MHz or another aeronautical mobile frequency, if considered necessary or desirable. Not all aeronautical stations maintain a continuous guard on the emergency frequency;

b.the distress message of an aircraft in distress being broadcast, if time and circumstances make this course preferable;

c.the aircraft transmitting on the maritime mobile service radiotelephony calling frequencies;

d.the aircraft using any means at its disposal to attract attention and make known its conditions (including the activation of the appropriate SSR mode and code);

e.any station taking any means at its disposal to assist an aircraft in distress;

f.any variation on the elements listed under b. above, when the transmitting station is not itself in distress, provided that such circumstance is clearly stated in the distress message.

2.The station addressed will normally be that station communicating with the aircraft or in whose area of responsibility the aircraft is operating.

5.2.2Action by the Station Addressed or First Station Acknowledging the Distress Message

5.2.2.1 The station addressed by aircraft in distress, or first station acknowledging the distress message shall:

a.immediately acknowledge the distress message;

b.take control of the communications or specifically and clearly transfer that responsibility, advising the aircraft if a transfer is made;

c.take immediate action to ensure that all necessary information is made available, as soon as possible, to:

1.the ATS unit concerned;

2.the aircraft operating agency concerned, or its representative, in accordance with preestablished arrangements;

NOTE: The requirement to inform the aircraft operating agency concerned does not have priority over any other action which involves the safety of the flight in distress, or of any other flight in the area, or which might affect the progress of expected flights in the area.

d.warn other stations, as appropriate, in order to prevent the transfer of traffic to the frequency of the distress communication.

(Annex 10, Vol II, 5.3.2.2.1)

5.2.3Imposition of Silence

5.2.3.1 The station in distress, or the station in control of distress traffic, shall be permitted to impose silence, either on all stations of the mobile service in the area or on any station which interferes with the distress traffic. It shall address these instructions “to all stations”, or to one station only, according to circumstances. In either case, it shall use:

–STOP TRANSMITTING;

–the radiotelephony distress signal MAYDAY.

(Annex 10, Vol II, 5.3.2.3.1)

5.2.3.2 The use of the signals specified in 5.2.3.1shall be reserved for the aircraft in distress and for the station controlling the distress traffic.

(Annex 10, Vol II, 5.3.2.3.2)

5.2.4Action by All Other Stations

5.2.4.1 The distress communications have absolute priority over all other communications, and a station aware of them shall not transmit on the frequency concerned, unless:

a.the distress is cancelled or the distress traffic is terminated;

b.all distress traffic has been transferred to other frequencies;

c.the station controlling communications gives permission;

d.it has itself to render assistance.

(Annex 10, Vol II, 5.3.2.4.1)

5.2.4.2 Any station which has knowledge of distress traffic, and which cannot itself assist the station in distress, shall nevertheless continue listening to such traffic until it is evident that assistance is being provided. (Annex 10, Vol II, 5.3.2.4.2)

5.2.5Termination of Distress Communications and of Silence

5.2.5.1When an aircraft is no longer in distress, it shall transmit a message cancelling the distress condition. (Annex 10, Vol II, 5.3.2.5.1)

5.2.5.2When the station which has controlled the distress communication traffic becomes aware that the distress condition is ended, it shall take immediate action to ensure that this information is made available, as soon as possible, to:

a.the ATS unit concerned;

b.the aircraft operating agency concerned, or its representative, in accordance with pre-estab- lished arrangements.

(Annex 10, Vol II, 5.3.2.5.2)

5.2.5.3 The distress communication and silence conditions shall be terminated by transmitting a message, including the words “DISTRESS TRAFFIC ENDED”, on the frequency or frequencies being used for the distress traffic. This message shall be originated only by the station controlling the communications when, after the reception of the message prescribed in 5.2.5.1 , it is authorized to do so by the appropriate authority. (Annex 10, Vol II, 5.3.2.5.3)

5.3RADIOTELEPHONY URGENCY COMMUNICATIONS

5.3.1Action by the Aircraft Reporting an Urgency Condition (except Medical Transports)

5.3.1.1 In addition to being preceded by the radiotelephony urgency signal PAN PAN, preferably spoken three times and each word of the group pronounced as the French word “panne”, the urgency message to be sent by an aircraft reporting an urgency condition shall:

a.be on the air-ground frequency in use at the time;

b.consist of as many as required of the following elements spoken distinctly and, if possible, in the following order:

1.the name of the station addressed;

2.the identification of the aircraft;

3.the nature of the urgency condition;

4.the intention of the person in command;

5.present position, level (i.e., flight level, altitude, etc., as appropriate) and heading;

6.any other useful information.

(Annex 10, Vol II, 5.3.3.1.1)

NOTE:

1.The foregoing provisions are not intended to prevent an aircraft broadcasting an urgency message, if time and circumstances make this course preferable.

2.The station addressed will normally be that station communicating with the aircraft or in whose area of responsibility the aircraft is operating.

5.3.2Action by the Station Addressed or First Station Acknowledging the Urgency Message

5.3.2.1 The station addressed by an aircraft reporting an urgency condition, or first station acknowledging the urgency message, shall:

a.acknowledge the urgency message;

b.take immediate action to ensure that all necessary information is made available, as soon as possible, to:

1.the ATS unit concerned;

2.the aircraft operating agency concerned, or its representative, in accordance with preestablished arrangements;

NOTE: The requirement to inform the aircraft operating agency concerned does not have priority over any other action which involves the safety of the flight in distress, or of any other flight in the area, or which might affect the progress of expected flights in the area.

c.if necessary, exercise control of communications.

(Annex 10, Vol II, 5.3.3.2.1)

5.3.3Action by Other Stations

5.3.3.1 The urgency communications have priority over all other communications, except distress, and all stations shall take care not to interfere with the transmission of urgency traffic. (Annex 10, Vol II, 5.3.3.3.1)

5.3.4Action by an Aircraft Used for Medical Transports

5.3.4.1The use of the signal described in 5.3.4.2, shall indicate that the message which follows concerns a protected medical transport pursuant to the 1949 Geneva Conventions and Additional Protocols. (Annex 10, Vol II, 5.3.3.4.1)

5.3.4.2For the purpose of announcing and identifying aircraft used for medical transports, a transmission of the radiotelephony urgency signal

PAN PAN, preferably spoken three times, and each word of the group pronounced as the French word “panne”, shall be followed by the radiotelephony signal for medical transports MAY-DEE-CAL, pronounced as in the French “mdical”. The use of the signals described above indicates that the message which follows concerns a protected medical transport. The message shall convey the following data:

a.the call sign or other recognized means of identification of the medical transports;

b.position of the medical transports;

c.number and type of medical transports;

d.intended route;

e.estimated time enroute and of departure and arrival, as appropriate; and

f.any other information such as flight altitude, radio frequencies guarded, languages used and secondary surveillance radar modes and codes.

(Annex 10, Vol II, 5.3.3.4.2)

5.3.5Action by the Station Addressed or by Other Stations Receiving a Medical Transports Message

5.3.5.1 The provisions of 5.3.2 and 5.3.3 shall apply as appropriate to stations receiving a medical transports message. (Annex 10, Vol II, 5.3.3.5.1)

6 COMMUNICATIONS FAILURE

6.1GENERAL RULES

6.1.1 An aircraft operated as a controlled flight shall maintain continuous air-ground voice communication watch on the appropriate communication channel of, and establish two-way communication as necessary with, the appropriate air traffic control unit, except as may be prescribed by the appropriate ATS authority in respect of aircraft forming part of aerodrome traffic at a controlled aerodrome. (Annex 2, 3.6.5.1)

NOTE 1: SELCAL or similar automatic signalling devices satisfy the requirement to maintain a listening watch.

NOTE 2: The requirement for an aircraft to maintain an air-ground voice communication watch remains in affect after CPDLC has been established.

6.1.2 If a communication failure precludes compliance with 6.1.1, the aircraft shall comply with the communication failure procedures in 6.2 below, and with such of the following procedures as are appropriate. The aircraft shall attempt to establish communications with the appropriate air traffic control unit using all other available means. In addition, the aircraft, when forming part of the aerodrome traffic at a controlled aerodrome, shall keep a watch for such instructions as may be issued by visual signals.

(Annex 2, 3.6.5.2)

6.1.2.1 If in visual meteorological conditions, the aircraft shall:

a.continue to fly in visual meteorological conditions;

b.land at the nearest suitable aerodrome; and

c.report its arrival by the most expeditious means to the appropriate air traffic control unit.

(Annex 2, 3.6.5.2.1)

(Annex 2, 3.6.5.2.2)

6.2AIR-GROUND COMMUNICATIONS FAILURE

6.2.1When an aircraft station fails to establish contact with the aeronautical station on the designated frequency, it shall attempt to establish contact on another frequency appropriate to the route. If this attempt fails, the aircraft station shall attempt to establish communication with other aircraft or other aeronautical stations on frequencies appropriate to the route. In addition, an aircraft operating within a network shall monitor the appropriate VHF frequency for calls from nearby aircraft. (Annex 10, Vol II, 5.2.2.7.1.1)

6.2.2If the attempts specified under 6.2.1 fail, the aircraft station shall transmit its message twice on the designated frequency(ies), preceded by the phrase “TRANSMITTING BLIND” and, if necessary, include the addressee(s) for which the message is intended. (Annex 10, Vol II, 5.2.2.7.1.2)

Procedures for Air Navigation Services (PANS) Recommendation — In network operation, a message which is transmitted blind should be transmitted twice on both primary and secondary frequencies. Before changing frequency, the aircraft station should announce the frequency to which it is changing. (Annex 10, Vol II, 5.2.2.7.1.2.1)

6.3RECEIVER FAILURE

6.3.1 When an aircraft station is unable to establish communication due to receiver failure, it shall transmit reports at the scheduled times, or positions, on the frequency in use, preceded by the phrase

“TRANSMITTING BLIND DUE TO RECEIVER FAILURE”. The aircraft station shall transmit the intended message, following this by a complete repetition. During this procedure, the aircraft shall also advise the time of its next intended transmission.

(Annex 10, Vol II, 5.2.2.7.1.3.1)

6.3.2An aircraft which is provided with air traffic control or advisory service shall, in addition to complying with 6.3.1, transmit information regarding the intention of the pilot-in-command with respect to the continuation of the flight of the aircraft. (Annex 10, Vol II, 5.2.2.7.1.3.2)

6.3.3When an aircraft is unable to establish communication due to airborne equipment failure it shall, when so equipped, select the appropriate SSR code to indicate radio failure. (Annex 10, Vol II, 5.2.2.7.1.3.3)

6.4TRANSPONDER PROCEDURES — RADIO COMMUNICATION FAILURE

6.4.1 The pilot of an aircraft losing two-way communications shall set the transponder to Mode A Code 7600. (PANS-OPS, Part VIII, 1.5)

NOTE: A controller observing a response on the radio communications failure code will ascertain the extent of the failure by instructing the pilot to SQUAWK IDENT or to change code. Where it is determined that the aircraft receiver is functioning, further control of the aircraft will be continued using code changes or IDENT transmission to acknowledge receipt of clearances issued. Different procedures may be applied to Mode S equipped aircraft in areas of Mode S coverage.

7 INTERCEPTION

7.1GENERAL

NOTE: The word “interception” in this context does not include intercept and escort service provided, on request, to an aircraft in distress, in accordance with the Search and Rescue Manual (Annex 2, 3.8).

7.1.1 Interception of civil aircraft shall be governed by appropriate regulations and administrative directives issued by contracting States in compliance with the Convention on International Civil Aviation, and in particular Article 3(d) under which contracting States undertake, when issuing regulations for their State aircraft, to have due regard for the safety of navigation of civil aircraft. Accordingly, in drafting appropriate regulations and administrative directives due regard shall be had to the provisions contained in the AIR TRAFFIC CONTROL Section, series 300, and the following paragraphs. (Annex 2, 3.8.1)

7.2ACTION BY INTERCEPTED AIRCRAFT

7.2.1 An aircraft which is intercepted by another aircraft shall immediately:

a.follow the instructions given by the intercepting aircraft, interpreting and responding to visual signals in accordance with the specifications in paragraph 7.4;

b.notify, if possible, the appropriate air traffic services unit;

c.attempt to establish radiocommunication with the intercepting aircraft or with the appropriate intercept control unit, by making a general call on the emergency frequency 121.5 MHz, giving the identity of the intercepted aircraft and the nature of the flight; and if no contact has been established and if practicable, repeating this call on the emergency frequency 243.0 MHz;

d.if equipped with SSR transponder, select Mode A, Code 7700, unless otherwise instructed by the appropriate air traffic services unit.

(Annex 2, Appendix 2, 2.1)

7.2.2If any instructions received by radio from any sources conflict with those given by the intercepting aircraft by visual signals, the intercepted aircraft shall request immediate clarification while continuing to comply with the visual instructions given by the intercepting aircraft. (Annex 2, Appendix 2, 2.2)

7.2.3If any instructions received by radio from any sources conflict with those given by the intercepting aircraft by radio, the intercepted aircraft shall

request immediate clarification while continuing to comply with the radio instructions given by the intercepting aircraft. (Annex 2, Appendix 2, 2.3)

7.3RADIOCOMMUNICATION DURING INTERCEPTION

7.3.1 If radio contact is established during interception but communication in a common language is not possible, attempts shall be made to convey instructions, acknowledgement of instructions and essential information by using the phrases and pronunciations in paragraph 7.5 and transmitting each phrase twice. (Annex 2, Appendix 2, 3)