Do the people who write these procedures ever try them out on a simulator?
The nat-pco site says that it might be necessary to overshoot the new track when establishing a reciprocal track. However, it still insists that we turn through ninety degrees while establishing a parallel track in the same direction. A 180 degree turn actually causes less of an offset than two 90 degree turns, due to the time taken to reverse the turn. In the simulator a few nights ago we did a 90 degree turn to establish on an offset in the same direction at FL350 and Mach .85. The aircraft deviated 28.4 miles from the original track.
The 90 degree turn technique worked perfectly when we were trying to achieve a 30nm offset, but not with a 15nm offset. I suggest that the procedure should be change to either;
1. If requiring to establish an offset on a reciprocal track then turn through 180 degrees and then continue the turn to achieve the 15nm offset as soon as possible.
2. If requiring to establish an offset on a track in the same direction then turn through 60 degrees and then reverse the turn so as to achieve a 15nm offset.
The 60 degree method gets the aircraft to 7.5nm from the original track (half way between the tracks) in exactly the same time as the 90 degree method, but avoids overshooting the required track. Obviously with the 180 degree turn there is no alternative to slightly overshootong the new track (by about 7nm) but why write a technique that guarantees a large overshoot when there is a much easier alternative?
Airclues