Boeing Engines.
Is anyone able to tell me, please, why the two inner engines on 747's as they pass over me contrailing appear to be "Toe-In", i.e., viewed from below, the engines are not parallel with the fuselage, the intakes appear to be nearer the fuselage than the jet pipe.
This in turn makes the two inner contrails bend outwards until they are clear behind the aircraft, where they appear to line up with the two outer contrails.
Hope that lot makes sense. Thanks. N.Z.