International Civil Aviation Organization (ICAO) Strategic Lateral Offset Procedures (SLOP)

Pilots should use the strategic lateral offset procedure (SLOP) in airspace where it is authorized. Aircraft operators and flight crews should verify its use with the State’s Aeronautical Information Publication (AIP). SLOP significantly reduces the risk of collision when non-normal events occur and provides a means to avoid wake turbulence. Flight crews with automatic offset tracking capability can select lateral offsets as an option. Authorized strategic lateral offsets include centerline, and up to 2 nautical miles RIGHT of centerline. For aircraft capable of offsets in one nautical mile increments, the choices are centerline, 1 nautical mile or 2 nautical miles right. For aircraft capable of offsets in tenths of a nautical mile, the choices are centerline, and any nautical mile increment up to 2 nautical miles right. Offsets to the left of centerline are PROHIBITED. Flight crews should avoid using Heading mode to offset. Air Traffic Control or ATC clearance is not required, and it is not necessary that ATC be advised.

[@peterbradshaw8177]

Wait. So which direction from centerline can SLOP be used? I don't think it was said enough. I forgot.

[@igornebov]

From pilot POV only to the right, never to the left

[@georgeconway4360]

There are really only two effective options 1R, 2R. This has been in use for 25 years or more unauthorized. I’ve been retired for 11 years but used 1R and never had ATC question it. The modern navigation systems are too accurate not to use it.The mid air over Brazil between the Business Jet and the B737 would never have happened if either crew had used an offset. Possibly the authorities would wake up if the next time it is two fully loaded 777s.

[@a.nelprober4971]

Is it common for people to use SLOP in non emergencies?

[@georgeconway4360]

@@a.nelprober4971 If either crew of the B737 or the business jet picked up at the factory were using 1R the midair would not have happened.

[@idkstillme4100]

Why not make the FMS automatically randomise the usage of SLOP?

[@georgeconway4360]

It only works when airplanes are flying on a fixed route in opposite directions. The use of 1R or 2R will prevent the head on collision. On the ground cars and trucks are kept separate by a painted line, and you just keep on the right side.

[@_Breakdown]

1:59 - - WOW - - 3 planes on the same centerline at different altitudes. 2:22 - - wake turbulence can through a plane off *EXAMPLE OF WAKE TURBULENCE ON ANOTHER PLANE:* kzbin.info/www/bejne/g5aafXRsopiFl6cfeature=shared (Go to 0:40 in the above-cited video)

[@ABStravel]

*_greeting from bali island_* _we are indonesia volcano & nationalpark tour organiser_ 🌅