Complex PBN is a brand new term to the 2016 edition of the manual, because new versions need new terms!
Basically 'complex PBN' is defined as PBN specifications and operations which cannot (yet) be trained sufficiently during initial pilot training, ie RNP AR APCH, and RNP 0.3 helicopter operations.
In simple terms, AR by any other name (and defining all helo RNP .3) The new manual made RNP a 'normal' operation, with specific approval required only for RNP AR APCH...
Currently, we are working on the RNP AR Visual, (such as Nice) trying to get approval for when the AR procedure is flown visual, authorization is not required....
and as always...a picture!
