Annex 12 is the shortest of the operational annexes and the one every pilot hopes never to meet in earnest: the standing organisation that searches for an aircraft in trouble and rescues its occupants. The exam wants its vocabulary of phases and units, the architecture of regions and coordination centres, the duties of an ordinary crew that stumbles onto an accident or a distress call, and the ground-air signal code that survivors stamp into snow and sand.
The vocabulary
The definitions are pure recall material, and several of them nest inside each other:
Uncertainty phase — a situation wherein UNCERTAINTY exists as to the safety of an aircraft and its occupants.
Alert phase — a situation wherein APPREHENSION exists as to the safety of an aircraft and its occupants.
Distress phase — a situation wherein there is REASONABLE CERTAINTY that an aircraft and its occupants are threatened by grave and imminent danger and require immediate assistance.
Emergency phase — the GENERIC term meaning, as the case may be, uncertainty phase, alert phase or distress phase.
Rescue coordination centre (RCC) — a unit responsible for promoting efficient organisation of search and rescue services and for coordinating the conduct of search and rescue operations within a search and rescue region; a rescue subcentre (RSC) is a unit subordinate to it, complementing it under the responsible authorities' provisions.
Search and rescue region (SRR) — an area of defined dimensions, ASSOCIATED WITH A RESCUE COORDINATION CENTRE, within which search and rescue services are provided.
Operator — a person, organization or enterprise engaged in or offering to engage in an aircraft operation.
Pilot-in-command — the pilot designated by the operator, or in the case of general aviation the owner, as being in command and charged with the safe conduct of a flight.
State of Registry — the State on whose register the aircraft is entered.
The organisation
Contracting States shall, individually or in cooperation with other States, arrange for the establishment and prompt provision of search and rescue services within their territories, resting on Article 25 of the Chicago Convention, in which States undertook to assist aircraft in distress in their territory as far as practicable. Over the sea the map is drawn by agreement: the portions of the high seas, and areas of undetermined sovereignty, in which SAR services are established are determined on the basis of REGIONAL AIR NAVIGATION AGREEMENTS. The basic elements of a SAR service:
a legal framework
a responsible authority
organised available resources
communication facilities
a workforce skilled in coordination and operational functions
And assistance is provided regardless of the nationality or status of the persons in distress, or the circumstances in which they are found.
The geography follows the flight information regions: States delineate the search and rescue regions (SRRs) within which they provide services, regions that shall not overlap, with neighbouring regions contiguous, and a rescue coordination centre is established for EACH search and rescue region (where aeronautical and maritime centres serve the same area, the closest practicable coordination, or a joint RCC, is arranged). The availability rule is absolute: SAR services, and each RCC, operate 24 HOURS A DAY, staffed by trained personnel proficient in the radiotelephony language (English proficiency for RCC radiotelephony personnel being a recommendation). Where the public cannot reach an RCC directly, it is likewise recommended that alerting posts, designated public or private units, stand between the person reporting an emergency and the centre.
The crew that finds trouble: procedures for the PIC
When a pilot-in-command observes another aircraft or a surface craft in distress, the Annex tasks the crew (if possible, and unless unreasonable or unnecessary) to keep the craft in sight until compelled to leave or released by the RCC, determine its position, and report to the RCC or ATS unit as much as possible of:
the type, identification and condition of the craft
its position
the time of observation in UTC
the number of persons observed
whether persons have been seen to abandon the craft
the on-scene weather
the apparent condition of survivors
the apparent best ground access route
Then act as instructed. And a rule of command falls on whoever is first: if the first aircraft to reach the scene is NOT a SAR aircraft, it takes charge of the on-scene activities of all later arrivals until the first SAR aircraft reaches the scene, handing over, by mutual agreement, to an aircraft that CAN talk to the RCC if it cannot itself establish communication.
Toward the people below, the aircraft has three tools. To convey information to survivors or surface rescue units without two-way communication, it drops communication equipment enabling direct contact, or drops a hard copy message. When a ground signal is displayed, it tells the survivors it understood by those same dropping means where practicable or, where that is not practicable, by the signal code's reply: rocking its wings by day, or flashing its landing lights on and off twice by night (or, failing those, its navigation lights); the absence of that signal means NOT understood. And to steer a ship toward a distress scene, the sequence is a piece of pre-radio theatre: circle the surface craft at least once, cross its projected course close ahead at low altitude rocking the wings (or varying the throttle or propeller pitch), then head in the direction the craft is to follow. Crossing the wake close astern at low altitude, again rocking the wings (or varying throttle or pitch), means instead that the ship is no longer required.
A different duty attaches to the radio. A pilot-in-command who intercepts a distress transmission shall, if feasible: acknowledge it; record the position of the craft in distress if given; take a bearing on the transmission; inform the appropriate RCC or ATS unit, giving all available information; and, at the pilot's discretion while awaiting instructions, proceed to the position given in the transmission.
The ground-air signal codes
When the survivors' only transmitter is the ground itself, Annex 12's appendix gives them five symbols, laid out with fabric, wood, stones or trampled snow, at least 2.5 m long and as conspicuous as possible:
V — require assistance.
X — require medical assistance.
N — no (negative).
Y — yes (affirmative).
An arrow — proceeding in this direction.
Rescue UNITS on the ground have their own seven-signal code, its commonest members worth recognising:
LLL — operation completed.
LL — we have found all personnel.
++ — we have found only some personnel.
XX — we are not able to continue, returning to base.
NN — nothing found, will continue to search.
Plus two arrow-based signals, for a party divided into groups and for a reported aircraft direction.