Originally Posted by
TonyC
No, the KC-135 windows are just like the B-707 windows which are just like the B-727 windows which are just like the B-737 windows. No windows in the back.
What some of them have -- KC-135s, EC-135s, RC-135s, some other -135s -- or had -- B-727s, B747s -- is/was a hole in the top of the fuselage near the back of the cockpit, and a mount beneath that hole that accepts a persicopic sextant. The mount seals the hole when the sextant is not in use, and it holds the sextant in place when mounted. It holds it both in the retracted position (nothing sticking out of the airplane), and in the extended position -- to "shoot" celestial bodies. THe hole is 1.375" in diameter -- slightly smaller than the diameter of a large chicken egg. That doesn't mean a large chicken egg wouldn't fit through it, though.
Eyebrow windows are handy for receiver air refueling.
.
Alright. Tony C comes through with the real facts. I've been itching to post this stuff, but thought I ought to read through the rest of the thread to see if someone had the real story. While I don't know what super early production 135s had in the way of extra windows, after 8 years and over 4000 hours on various 135 and E-3 models, Tony has his facts straight on the eyebrow windows and sextant port. And like others have mentioned, I've flown several 727s that had sextant ports, usually -100 models, built before omega and ins were available.