These deviations occur well within the width af an airway. The airways are 8 miles wide, 4 miles either side of centerline. I am talking about deviations that are approximately 1/8 mile to 1/2 mile either side of center. As long as the aircraft is correcting to course, the controllers do not say anything. It usually takes a couple of miles off course and diverging to have the controllers say anything. The autopilot will still fly better than a pilot hand flying most of the time.
Plus there is separation provided of a few miles in front, behind and to the side of the aircraft. Where this seperation cannot be maintained, different altitudes are flown by the aircraft.
We do not have GPS or INS in our aircraft. We navigate with VORs and NDBs. It is embarrasing when the controller clears us direct to an intersection. We have to reply, "unable." We are vector equipped though.
Forgive me as sometimes I forget, there are aircaft equipped with better navigational equipment. I have no idea if this was the cause of the unique contrail seen. But, it is a posible explanation or scenario. So far no one has come up with the type of aircraft used.
Could have been an older corporate jet with out INS or GPS.
Could have been a pilot hand flying and not holding course well.
Could of been a pilot wanting to mess with us spotters and make us post a couple of pages of speculation as to what caused that anomaly.
