(5)
If prior clearance cannot be obtained, an ATC clearance shall be obtained at the earliest possible time and, until a revised clearance is received, the pilot shall:
(a)
Leave the assigned route or track by initially turning 90 degrees to the right or to the left. When possible, the direction of the turn should be determined by the position of the aircraft relative to any organized route or track system. Other factors which may affect the direction of the turn are:
1 The direction to an alternate airport, terrain clearance;
2 Any lateral offset being flown; and
3 The flight levels allocated on adjacent routes or tracks.
FAA NOTE: A turn of less than or greater than 90 degrees may be required depending on the type of contingency and whether the pilot intends to continue in the same direction or reverse course.
(b) Following the turn, the pilot should:
1 If unable to maintain the assigned flight level, initially minimize the rate of descent to the extent that is operationally feasible;
2 Take account of other aircraft being laterally offset from its track;
3 Acquire and maintain in either direction a track laterally separated by 15 NM (28 km) from the assigned route; and
4 Once established on the offset track, climb or descend to select a flight level which differs from those normally used by 500 ft. (150m);
(c)
Establish communications with and alert nearby aircraft by broadcasting, at suitable intervals; aircraft identification, flight level, position (including ATS route designator or the track code, as appropriate) and intentions on the frequency in use and on 121.5 MHz (or, as back-up, on the inter-pilot air-to-air frequency 123.45 MHz);
(d)
Maintain a watch for conflicting traffic both visually and by reference to ACAS (TCAS) (if equipped);
(e)
Turn on all aircraft exterior lights (commensurate with appropriate operating limitations);
(f) Keep the SSR transponder on at all times; and
(g)
Take action as necessary to ensure the safety of the aircraft.
(6)
When leaving the assigned track to acquire and maintain the track laterally separated by 15 NM (28 km), the flight crew, should, where practicable, avoid overshooting the track to be acquired, particularly in airspace where a 30 NM (55.5 km) lateral separation minimum is applied.
(SPEC/ICAO 4444 15.2, FAA International NOTAMS Sec. 2)
d. EXTENDED RANGE OPERATIONS BY AIRCRAFT WITH TWO-TURBINE POWER-UNITS (ETOPS) - If the contingency procedures are employed by a twin engine aircraft as a result of an engine shutdown or failure of an ETOPS critical system, the pilot should advise ATC as soon as practicable of the situation, reminding ATC of the type of aircraft involved, and request expeditious handling.
(SPEC/ICAO 4444 15.2, FAA International NOTAMS Sec. 2)
e. WEATHER DEVIATION PROCEDURES FOR OCEANIC-CONTROLLED AIRSPACE
(1)
The following procedures are intended to provide guidance for deviations around adverse meteorological conditions. All possible circumstances cannot be covered. The pilot’s judgment shall ultimately determine the sequence of actions taken and ATC shall render all possible assistance.
(2)
If the aircraft is required to deviate from track to avoid weather and prior clearance cannot be obtained, an air traffic control clearance shall be obtained at the earliest possible time. In the meantime, the aircraft shall follow the procedures detailed in paragraph (6)(b) below.
(3)
The pilot shall advise ATC when weather deviation is no longer required, or when a weather deviation has been completed and the aircraft has returned to the centerline of its cleared route.
(4)
Obtaining priority from ATC when weather deviation is required:
(a)
When the pilot initiates communications with ATC, rapid response may be obtained by stating “WEATHER DEVIATION REQUIRED” to indicate that priority is desired on the frequency and for ATC response.
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