Pacific - Contingency Procedures

Question 1

In oceanic airspace, what are the general procedures when prior clearance cannot be obtained and deviation from cleared route is required?

Answer 1

Turn at least 30deg right or left - maintain flight level or minimise rate of descent as far as operationally feasible
Offset and parallel track by 5nm
Once offset by 5nm, either:
Descend below FL290, or
Establish a 500ft vertical offset
Maintain visual and TCAS watch for conflicting traffic
Turn on all exterior lights
Squawk 7700 and emergency function of ADS-C or ABS-B as appropriate
Advise ATC of deviation as soon as practical
Use voice and/or CPDLC to communicate contingency/emergency
If using voice, prefix with MAY DAY or PAN PAN as appropriate
Alert nearby aircraft on 121.5MHz:
Aircraft ID
Flight Level
Position - ATS route designator
Nature of distress
Intention

Question 2

In oceanic airspace, what is the phraseology used where priority weather deviation is required and what is the contingency procedure where a revised clearance cannot be obtained?

Answer 2

Priority required : “WEATHER DEVIATION REQUIRED” via Voice or CPDLC

When a devices clearance cannot be obtained:
Deviate away from the track/route system
Broadcast on 121.5MHz:
Aircraft Identification
Flight Level
Position - ATS route designator
Intentions
Watch for conflicting traffic visually and via TCAS
Turn on exterior lights

Deviation less than 5nm - maintain flight level

Deviation Greater than 5nm - maintain flight level until 5nm and then proceed as follows:
Original Track EAST - LEFT TURN DESCEND 300ft (E-L-D)
Original TRACK EAST - RIGHT TURN CLIMB 300ft (E-R-C)
Original Track WEST - LEFT TURN CLMIB 300ft (W-L-C)
Original Track WEST - RIGHT TURN DESCEND 300ft (W-R-D)

If a clearance is obtained to deviate, and further deviation is required but cannot be obtained - follow the above climb/descent prior to initiation any further diversion

When returning to track, be at assigned flight level when within 5nm of route centreline

Continue to attempt to contact ATC and advise intentions
If conflicting traffic, adjust path of aircraft to avoid conflict as required