And flight engineers 
I think the INS cut out the Nav with the 747 intro!
Akcherly ... the INS cut out the Nav on the 707, tho' the S/O P.3, (Nav qualified) was still carried " Just in Case", but had stopped actually doing any navigating before the 707 was retired.
The early 747's still had the sextant mounting, having been initially designed when Astro was King, but it was designated as the smoke removal port when the 747 was finally introduced into service.
Can anyone name the crew? I am an ex 747 Capt.
Phil Brentnall maybe ? Can't remember..