Initial Action
11.3.2 The aircraft should leave its assigned route or track by initially turning at least 45° to the right or left whenever this is feasible. The direction of the turn should, where appropriate, be determined by the position of the aircraft relative to any organised route or track system (e.g. whether the aircraft is outside, at the edge of, or within the system). Other factors which may affect the direction of turn are: direction to an alternate airport, terrain clearance, levels allocated on adjacent routes or tracks and any known SLOP off sets adopted by other nearby traffic.
Subsequent Action
11.3.3 An aircraft that is able to maintain its assigned flight level, after deviating 10 NM from its original cleared track centerline and therefore clear of any potentially conflicting traffic above or below following the same track, should:
a) Climb or descend 1000 ft if above FL410
b) Climb or descend 500 ft when below FL410
c)Climb 1000 ft or descend 500 ft if at FL410
11.3.4 An aircraft that is unable to maintain its assigned flight level should, whenever possible,
d)initially minimize its rate of descent when leaving its original track centerline and then expedite descent to a
e)feasible flight level which differs from those normally used by 500 ft if below FL410 (or by 1000 ft if above
f) FL410