In Simple words
WHEN AN AIRCRAFT IS THREATENED BY SERIOUS AND / OR IMMINENT DANGER AND REQUIRES IMMEDIATE ASSISTANCE, THE AIRCRAFT WILL TAKE DISTRESS ACTION
SOME OF THE CONDITIONS REQUIRING MAY DAY CALL ARE:
- ENGINE ON FIRE AND CRASHING, FIRE ALARM ACTIVATED
- ENGINE FAILURE AND FORCELANDING,
- AIRCRAFT OUT OF CONTROL OR UNSTABLE DUE TO BIRD HIT
- BIRD HIT CONTROLS AFFECTED, STRUCTURAL DAMAGE,
- CO PILOT FAINTED, LOOSING HEIGHT, ENTERED SPIN,
- HYDRAULIC FAILURE, RUDDER STUCK,
- AIRCRAFT SKIDS OF RUNWAY/ UNDERSHOOT / OVERSHOOTS. AIRCRAFT UNSTABLE, CRASHED NEAR A PLACE. PRIMARY ALTIMETER FAILURE
- HIJACK, BOMB THREAT IN AIR, ENTERING PROHIBITED AREA, SEE SERIES OF RED AND GREEN FLARES ,
HAVE A LOOK AT THE INTENTION AND DECIDE, IN CASE INTENTION IS NOT GIVEN FORCE LANDING STRAIGHT AHEAD OR LANDING AT
Just to increase the knowledge some definitions and actions by various agencies are mentioned below. The Format of call is after that….
Distress. Distress is a condition of being threatened by serious and/or imminent danger and of requiring immediate assistance.
Urgency. Urgency is a condition concerning the security of a ship, aircraft or other vehicle, or of some person on board or within sight, but which does not require immediate assistance.
Safety. Safety is that condition which necessitates the transmission of a message concerning the safety of navigation or providing important meteorological warnings.
Distress. Distress traffic shall have absolute priority over all other transmissions. All stations which hear the distress call shall immediately cease any transmission capable of interfering with the distress traffic and shall continue to listen on the frequency used for the emission of the distress call.
Urgency. Urgency traffic shall have priority over all other communications, except All stations which hear the urgency signal shall take care not to interfere with the transmission of the message which follows the urgency signal.
In cases of distress, urgency or safety, transmissions: by radiotelephony, shall be made slowly and distinctly, each word being clearly pronounced to facilitate transcription.
AIRCRAFT DISTRESS PROCEDURES
The procedures detailed in Chapter 2 are generally applicable to aircraft in distress and shall be employed in communications between aircraft stations and stations in the maritime mobile service. However, the following procedures will normally be employed by stations within the aeronautical mobile service, and will be used by aircraft operating on military communications network.
Action by Aircraft in Distress
An aircraft commander should have no hesitation in declaring a state of distress if there is any indication that such exists. As soon as distress conditions arise, all installed automatic emergency equipment (e.g. IFF etc.) should be switched on. When the distress conditions cease to exist, a message is to be sent cancelling the distress condition.
The distress signal shall be used at the commencement of the first distress communication. It shall also be used, if it is considered necessary, at the commencement of any subsequent distress communication.
In addition to being preceded by the distress call (SOS or MAYDAY, depending on the mode of communication), preferably transmitted three times, the distress message sent by an aircraft in distress should:
1. Be on the air-ground frequency in use at the time.
2. Consist of as many as possible of the following elements, in the following order:
- Position and time
- Air speed
- Aircraft type
- Nature of distress
- Captain’s intentions
- Any other information that may facilitate rescue (Endurance, fuel on board, POB
- ICAO distress message should consist of as many as possible of the following elements, in the following order:
- Nature of Distress
- Captains Intentions
- Any other information that may facilitate rescue Distress Message
The provision above are not intended to prevent:
The distress message of an aircraft in distress being made on another aeronautical mobile frequency, if considered necessary or desirable. In many areas, a continuous watch by aeronautical stations is maintained on 121.5 MHz and/or 243MHz.
The distress message of an aircraft in distress being broadcast, if time and circumstances make this course preferable.
The aircraft transmitting on the maritime mobile international distress frequencies.
The aircraft using any means at its disposal to attract attention and make known its condition (including the activation of the appropriate IFF mode and code).
Any station taking any means at its disposal to assist an aircraft in distress.
Any variation of the elements of the distress message when the transmitting station is not itself in distress, provided that such situation is clearly stated in the distress message.
Action by Station Addressed
The station addressed by the station in distress, or the first station acknowledging the distress message shall:
1. Immediately acknowledge the distress message. (See Figure 3-1)
2. Take control of the communications, or specifically and clearly transfer that responsibility, advising the aircraft if a transfer is made.
3. Take immediate action to ensure that all necessary information is made available as soon as possible to:
- The Air Traffic Service (ATS) unit concerned.
- The aircraft operating agency concerned, or its representative, in accordance with pre-established arrangements. (This requirement 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 the expected flights in the area.)
- 4. Warn other stations as appropriate, in order to prevent the transfer of traffic to the frequency of the distress communication. Imposition of Silence
The station in distress, or the station in control of the distress traffic, may 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 the form of the signal will be:
By voice – STOP TRANSMITTING – MAYDAY
By RATT – QRT SOS
The use of these signals is reserved for the aircraft station in distress and for the station controlling the distress traffic.
Action by all Other Stations
Distress communications have absolute priority over all other communications, and a station aware of them shall not transmit on the frequency concerned, unless:
1. The distress is cancelled or the distress traffic is terminated.
2. All distress traffic is transferred to other frequencies.
3. It had itself to render assistance.
Any station which has knowledge of distress traffic, shall nevertheless continue listening to such traffic until it is obvious that assistance is being provided.
Termination of Distress
When an aircraft is no longer in distress, it shall transmit a message cancelling the distress condition. When 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:
1. The ATS unit concerned.
2. The aircraft operating agency concerned, or its representative, in accordance with pre-established arrangements
Termination of Silence
The distress communication and silence condition shall be terminated by transmitting a message, on the frequency or frequencies being used for distress traffic. This message shall be transmitted in the format shown below. This message shall be originated only by the station controlling the communications when, after reception of the message cancelling the distress condition, it is authorised to do so by the appropriate authority
Format of Call
CALL WILL GO TO CONTROL INCASE YOU ARE IN SOMEONE’S CONTROL ELSE TO RADIO
BREAK THE CALL INTO FOUR PARTS AND DO ONE THING AT A TIME AND DO IT WELL
ADDRESSING : FROM BLANK SHEET (MAYDAY X 3 TIMES WHOM ARE YOU CALLING WHO YOU ARE
CONDITION : READ STRAIGHT FROM QUESTION PAPER
INTENTION: READ STRAIGHT FROM QUESTION PAPER OR SAY FORCE LANDING STRAIGHT AHEAD ( IN CASE AIRCRAFT IS OUT OF CONTROL ELSE LANDING AT —-)
ADDITIONAL INFORMATION: P F C S P (Position, FL, Course, Speed, POB)
MAY DAY MAY DAY MAY DAY DELHI CONTROL INDAIR 430 AIRBUS
NUMBER ONE ENGINE HAS FAILED
POSITION JAIPUR 0430 FL 320 COURSE 300 SPEED 450 PERSONS ONBOARD TWO FIFE ZERO OVER.
Best of Luck..