c130 navigation
Serious answer to the question. It is generally the J's and we put a notam in as a safety net in case we cannot get the 5's as is usually the case. Because we are so short of aircraft, as the K's are frightened to deploy operationally, often a boring west country route for an NVG tick or to complete a live drop on SPTA is the only option. Unfortunately because our nav kit is so good we often do follow the exact line to split second accuracy. The + or - 15 minutes is a throw back to the K's.