Quote:

The Boeing 707 has used BOTH types of the AP.

 :-?

I worked on 720s, 707-100 and 300(320, 320ADV, 320ADV with Improved Cowl, 320ADV with Stage 2 hush kits and 320ADV with stage 3 hush kitted JT3D-7 engines) from 1975 to 1998 as a ground maitainance engineer (FAA A&P and UK CAA Avionics) and flew 6,000+ hours as flight engineer on all different types but never once have I seen a 707 with a Sperry autopilot.
I have never been asked any questions about Sperry autopilots during any type technical exams and never seen any reference to them in Boeing maitainance manuals or Boeing or airline (TWA, Pan AM, NorthWest, BOAC, Air France, Lufthansa, Amercian, Pakistan, China etc, etc) operating manuals.

I have searched Airliners. net for pictures and searched google for information but cannot find any reference to B707s with Sperry autopilots. Maybe some obscure military version was fitted with one but I never heard of it.

Steve