11 Distress and Urgency

(1)

CO M M U N IC AT IO N S

11.1 Deﬁnitions

Distress

Distress is deﬁned as a condition of being threatened by serious and/or imminent danger and of requiring immediate assistance.

Urgency

Urgency is 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.

11.1.1 Distress and Urgency Messages

The word “MAYDAY” spoken at the start identiﬁes a distress message, and the words “PAN PAN” spoken at the start identiﬁes an urgency message. The words “MAYDAY” or “PAN PAN”, as appropriate, should preferably be spoken three times at the start of the initial distress or urgency call.

• Distress messages have priority over all other transmissions, and urgency messages have priority over all transmissions except distress messages

• Pilots making distress or urgency calls should attempt to speak slowly and clearly so as to avoid any unnecessary repetition

• Pilots should adapt the phraseology procedures in this chapter to their speciﬁc needs and to the time available

• Pilots should seek assistance whenever there is any doubt as to the safety

of a ﬂight. In this way the risk of a more serious situation developing can often be avoided

11.1.2 Frequencies and SSR Codes that

can be Used

A distress or urgency call should normally be made on the frequency in use at the time. Distress communications should be continued on this frequency unless it is considered that better assistance can be provided by changing to another frequency. The frequency 121.5 MHz has been

designated the international aeronautical emergency frequency although not all aeronautical stations maintain a continuous watch on that frequency. These provisions are not intended to prevent the use of any other communications frequency if considered necessary or desirable, including the maritime mobile service RTF calling frequencies. If the ground station called by the aircraft does not reply, then any other ground station or aircraft shall reply and give whatever assistance possible.

A station replying (or originating a reply) to an aircraft in distress or urgency should provide only such advice, information and

11 Distress and Urgency

(2)

instructions as is necessary to assist the pilot. Superﬂuous transmissions may be distracting at a time when the pilot’s hands are already full.

Aeronautical stations shall refrain from further use of a frequency on which distress or urgency trafﬁc is heard, unless directly involved in rendering assistance or until after the emergency trafﬁc has been terminated. When a distress message has been

intercepted which apparently receives no acknowledgement, the aircraft intercepting the distress message should, if time and circumstances seem appropriate, acknowledge the message and then broadcast it.

11.1.3 Emergency SSR Codes

• A7500 – Unlawful interference (e.g. hijacking)

• A7600 – Radio failure

• A7700 – Emergency (MAYDAY) The above “A” indicates a Mode-A type of transponder that does not reply with altitude when interrogated. The above codes shall be squawked with Mode-C, altitude encoding, if equipped. In addition, Mode S transponders provide replies to Mode-A, Mode-C as well as discrete Mode-S.

Fig. CM 11.1 MAYDAY procedure

MAYDAY MAYDAY MAYDAY N710EC engine on fire making forced landing 20 miles south of Walden passing 3000 feet heading 360 OR MAYDAY Walden tower N710EC engine failed will attempt to land your field, 5 miles south, 4000 feet heading 360 OR MAYDAY Walden tower N710EC engine failed will attempt to land your field, 5 miles south, 4000 feet heading 360 Cleared straight-in runway 35 QNH 1008, number 1 N710EC

N710EC Walden tower roger MAYDAY

N710EC Walden tower roger MAYDAY cleared straight-in runway 35 wind 360 degrees 10 knots QNH 1008 you are number one

(3)

C O M M U N IC AT IO N S

11.2 Distress Messages

11.2.1 Aircraft in Distress

A distress message should contain as many as possible of the following elements, if possible in the order shown:

MAYDAY (preferably spoken 3 times) a) Name of the station addressed; b) Identification of the aircraft; c) Nature of the distress condition; d) Intention of the person in command; e) Position, level and heading of the aircraft; f) Any other useful information.

These provisions are not intended to prevent the aircraft using any means at its disposal to attract attention and make known its condition (including the activation of the appropriate SSR code, 7700), nor any station taking any means at its disposal to assist an aircraft in

distress. Variation on the elements listed above is permissible when the transmitting station is not itself in distress, provided that such circumstance is clearly stated.

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

11.2.2 Imposition of Silence

An aircraft in distress or a station in control of distress traffic may impose silence, either;

• On all aircraft on the frequency

• On a particular aircraft which interferes with the distress traffic

Aircraft so requested will maintain radio silence until advised that the distress traffic has ended.

Fig. CM 11.3 Cancelling distress

Walden tower NEC cancel distress engine serviceable, runway in sight request landing Runway 35 cleared to land NEC

NEC runway 35 cleared to land

Fig. CM 11.2 Distress - imposition of silence

All stations Walden tower stop transmitting

MAYDAY

Fastair 345 stop transmitting MAYDAY

(4)

11.2.3 Termination of Distress and Silence

When an aircraft is no longer in distress, it shall transmit a message cancelling the distress condition by transmitting a message including the words CANCEL DISTRESS. When the ground station controlling the distress trafﬁc is aware that the aircraft is no longer in distress it shall terminate the distress communication and silence condition, by transmitting a message including the words DISTRESS TRAFFIC ENDED.

Fig. CM 11.4 Urgency procedure

Pan-Pan Pan-Pan Pan-Pan Walden tower N710EC Cessna172 2000 feet heading 190 above cloud unsure of my position request heading to Walden Heading 160 N710EC Pan-Pan Pan-Pan Pan-Pan Walden tower N710EC 10 miles north at 2000 feet passenger with suspected heart attack request priority landing

Runway 17 QNH 1008 NEC Pan-Pan Pan-Pan Pan-Pan Walden tower GBBCC intercepted urgency call from N710EC passenger with suspected heart attack requesting priority landing Walden his position 10 miles north at 2000 feet

(if N710NEC does not acknowledge this message GBBCC will relay)

N710EC fly heading 160

NEC Walden tower number 1 straight-in runway 17 wind 180 degrees 10 knots QNH 1008 ambulance requested

GBBCC roger

N710EC Walden tower runway 35 wind 340 degrees 10 knots QNH 1008 traffic nil

11.3 Urgency Messages

An urgency message should contain as many of the elements detailed in the distress message as are required by the circumstances. The call should be made on the frequency in use at the time, and the station addressed will normally be that station communicating with the aircraft, or in whose area of responsibility the aircraft is operating. All other stations should take care not to interfere with the transmission of urgency trafﬁc.

(5)

11.4 PAN Medical Procedure

The type of ﬂight to which PAN MEDICAL applies:

According to ICAO Aeronautical

Telecommunications, Annex 10 Volume 2, the following action is to by taken an aircraft used for medical transports. The use of the signal described below shall indicate that the message which follows concerns a protected medical transport pursuant to the 1949 Geneva Conventions and Additional Protocols.

For 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 “medical”. The use of the signals described above indicates that the message which follows concerns a protected medical transport. List of the content of a PAN MEDICAL message. The message shall convey the following data, preferably in the following sequence:

a) The call sign or other recognised 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 en route and of departure and arrival, as appropriate;

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