EMERGENCY

1 DEFINITIONS

NOTE: See AIR TRAFFIC CONTROL — International Civil Aviation Organization Definitions.

AIRCRAFT STATION — A mobile station in the aeronautical mobile service, other than a survival craft station, located on board an aircraft.

DISTRESS — A condition of being threatened by serious and/or imminent danger and of requiring immediate assistance.

RADIOTELEPHONY NETWORK — A group of radiotelephony aeronautical stations which operate on and guard frequencies from the same family and which support each other in a defined manner to ensure maximum dependability of air-ground communications and dissemination of air-ground traffic.

RESCUE CO-ORDINATION CENTER — A unit responsible for promoting efficient organization of search and rescue service and for co-ordinating the conduct of search and rescue operations within a search and rescue region.

RESCUE UNIT — A unit composed of trained personnel and provided with equipment suitable for the expeditious conduct of search and rescue.

SEARCH AND RESCUE SERVICES UNIT — A generic term meaning, as the case may be, rescue co-ordination center, rescue subcenter or alerting post.

URGENCY — A condition concerning the safety of an aircraft or other vehicle, or of some person on board or within sight, but which does not require immediate assistance.

2 EMERGENCY PROCEDURES

2.1GENERAL

2.1.1The various circumstances surrounding each emergency situation preclude the establishment of exact detailed procedures to be followed.

(Doc 4444, 15.1.1)

2.1.2Air traffic control units shall maintain full and complete coordination, and personnel shall use their best judgement in handling emergency situations. (Doc 4444, Part III, 16.1.1)

NOTE: To indicate that it is in a state of emergency, an aircraft equipped with an SSR transponder might operate the equipment as follows:

a. on Mode A, Code 7700; or

b.on Mode A, Code 7500, to indicate specifically that it is being subjected to unlawful interference.

2.2PRIORITY

2.2.1 An aircraft known or believed to be in a state of emergency, including being subjected to unlawful interference, shall be given priority over other aircraft. (Doc 4444, 15.1.2)

2.3DISTRESS FREQUENCIES

2.3.1The ICAO Communication Procedures require that an aircraft in distress when it is airborne should use the frequency in use for normal communications with aeronautical stations at the time. However, it is recognized that, after an aircraft has crashed or ditched, there is a need for designating a particular frequency or frequencies to be used in order that uniformity may be attained on a world-wide basis, and so that a guard may be maintained or set up by as many stations as possible including direc- tion-finding stations, and stations of the Maritime Mobile Service.

2.3.2The frequency 2182 kHz is the international distress frequency for radiotelephony to be used for that purpose by ship, aircraft and survival craft stations when requesting assistance from the maritime service.

2.3.3The frequency 4125 kHz is also authorized to enable communications between stations in the maritime mobile service and aircraft stations in distress.

2.3.4Similarly, the frequency 500 kHz is the international distress frequency for radiotelegraphy to be used for that purpose by ship, aircraft and survival craft stations when requesting assistance from the maritime service.

2.3.5With respect to survival craft stations the following emergency / distress frequencies are provided:

a.VHF — 121.5 MHz;

b.UHF — 243.0 MHz;

c.HF — 500 kHz, 2182 kHz, 8364 kHz.

(Annex 10, Vol V, Chapter 2 Introduction)

2.4TRANSPONDER OPERATIONS

— EMERGENCY

2.4.1 The pilot of an aircraft in a state of emergency shall set the transponder to Mode A Code 7700 unless ATC has previously directed the pilot to operate the transponder on a specified code. In the latter case, the pilot shall continue to use the specified code unless otherwise advised by ATC. However, a pilot may select Mode A Code 7700 whenever there is a specific reason to believe that this would be the best course of action. (Doc 8168, Vol I, Part III, Section 3, Chapter 1, 1.4).

2.5DISTRESS AND URGENCY SIGNALS

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

2.5.1.1 The following signals, used either together or separately, mean that grave and imminent danger threatens, and immediate assistance is requested:

a.a signal made by radiotelegraphy or by any other signalling method consisting of the group SOS (. . . - - - . . . in the Morse Code);

b.a radiotelephony distress signal consisting of the spoken word MAYDAY;

c.a distress message sent via data link which transmits the intent of the word MAYDAY;

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)

2.5.2.2The 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)

3 UNLAWFUL INTERFERENCE

3.1GENERAL

3.1.1An aircraft which is being subjected to unlawful interference shall endeavor to notify the appropriate ATS unit of this fact, any significant circumstances associated therewith and any deviation from the current flight plan necessitated by the circumstances, in order to enable the ATS unit to give priority to the aircraft and to minimize conflict with other aircraft. (Annex 2, 3.7)

3.1.2When an air traffic services unit knows or believes that an aircraft is being subjected to unlawful interference, no reference shall be made in ATS air-ground communications to the nature of the emergency unless it has first been referred to in 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

3.2.1If there is unlawful interference with an aircraft in flight, the pilot-in-command shall attempt to set the transponder to Mode A Code 7500 in order to indicate the situation: If circumstances so warrant, Code 7700 should be used instead. (Doc 8168, Vol I, Part III, Section 3, Chapter 1, 1.6.1).

3.2.2If a pilot has selected Mode A Code 7500 and has been requested to confirm this code by ATC (in accordance with 1.1.5), the pilot shall, according to circumstances, either confirm this or not reply at all. (Doc 8168, Vol I)

NOTE: If the pilot does not reply, ATC will take this as confirmation that the use of Code 7500 is not 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 pilot-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)

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 distress 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.

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:

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

1.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;

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

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

4.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);

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

6.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.

b.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:

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

b.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

has been received and acknowledged, at, or as close as possible to, the estimated time of arrival resulting from the current flight plan;

f.complete a normal instrument approach procedure as specified for the designated navigation aid or fix; and

g.land, if possible, within thirty minutes after the estimated time of arrival specified in e. or the last acknowledged expected approach time, whichever is later.

NOTE:

a.The provision of air traffic control service to other flights operating in the airspace concerned will be based on the assumption that an aircraft experiencing radio failure will comply with the rules in 6.1.2.2.

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)

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)

7.2.2 If any instructions received by radio from any sources conflict with those given by the intercepting aircraft by visual signals, the intercepted aircraft

RADIO COMMUNICATION FAILURE

6.4.1 The pilot of an aircraft losing two-way communications shall set the transponder to Mode A Code 7600. (Doc 8168, Vol I, Part III, Section 3, Chapter 1, 1.5)

NOTE: A controller who observes an SSR response indicating selection of the communications failure code will determine the extent of the failure by instructing the pilot to SQUAWK IDENT or to change code. If 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. 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 — International Civil Aviation Organization Rules of the Air, 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

to comply with the visual instructions given by the intercepting aircraft. (Annex 2, Appendix 2, 2.2)

7.2.3 If 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)