b. STRATEGIC LATERAL OFFSET PROCEDURES (SLOP)

(1)
The intent of this procedure is to reduce risk (increase the safety margin) by distributing aircraft laterally and equally across the three available positions. Pilots should use the SLOP as standard operating practice in the course of normal oceanic operations to mitigate collision risk and wake turbulence. This procedure provides for the application of lateral offsets within the following guidelines:

(a)
Along a route or track there will be three positions that an aircraft may fly: centerline or one or two miles right; and

(b) Offsets will not exceed 2 NM right of centerline.

(2)
GUIDELINES - Distributing aircraft laterally and equally across the three available positions is now a standard ICAO operating procedure and pilots are required to adopt this procedure.  It should also be noted that:

(a)
Aircraft without automatic offset programming capability must fly the centerline.

(b)
Operators capable of programming automatic offsets may fly the centerline or offset one or two nautical miles right of centerline to obtain lateral spacing from nearby aircraft.  An aircraft overtaking another aircraft should offset within the confines of this procedure, if capable, so as to create the least amount of wake turbulence for the aircraft being overtaken.

(c)
Pilots should use whatever means available (TCAS, radios, visual, etc . . .) to determine the best flight path to fly.

(d)
For wake turbulence purposes, pilots may only fly one of the three positions listed above.  For additional options and inflight contingency procedures refer to appropriate Area Planning documents.

NOTE: It is recognized that the pilot will use his/her judgment to determine the action most appropriate to any given situation and has the final authority and responsibility for the safe operation of the aircraft. The use of air-to-air channel, 123.45, may be used to coordinate the best wake turbulence offset option.

(e)
Pilots may apply an offset outbound at the oceanic entry point but must return to centerline at the oceanic exit point.

(f)
Aircraft transiting radar-controlled airspace mid-ocean are to remain on their established offset positions.

(g)
 There is no ATC clearance required for this procedure and it is not necessary that ATC be advised.

(h)
Voice Position reports are to be based on the current ATC clearance and not the positions.

(SPEC/ICAO Doc 4444 15.2.4, NAT MNPS 8.5)
c. SPECIAL PROCEDURES FOR IN-FLIGHT CONTINGENCIES IN OCEANIC AREAS AND REMOTE AREAS
(1)
The following general procedures are intended as guidance only. Although all possible contingencies cannot be covered, they provide for cases of inability to maintain assigned level due to:

(a)
inability to maintain assigned flight level due to meteorological conditions, aircraft performance or pressurization

failure; 
(b)  enroute diversion across the prevailing traffic 
flow; and 
(c)  loss of, or significant reduction in, the required 

navigation capability when operating in an airspace where the navigation performance accuracy is a prerequisite to the safe conduct of flight operations.
(2)
The procedures are applicable primarily when rapid descent and/or turn-back, or diversion to an alternate airport is required. The pilot's judgment shall determine the sequence of actions to be taken, taking into account specific circumstances.

(3)
 If an aircraft is unable to continue the flight in accordance with its ATC clearance, and/or an aircraft is unable to maintain the navigation performance accuracy specified for the airspace, a revised clearance shall be obtained, whenever possible, prior to initiating any action.

(4)
The radiotelephony distress signal (MAYDAY) or urgency signal (PAN PAN) preferably spoken three times shall be used as appropriate. Subsequent ATC action with respect to that aircraft shall be based on the intentions of the pilot and the overall air traffic situation.
　
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