Cool history to know about our beloved plane!

It’s obvious to most, but the E's started out as A's.

When the AD showed little willingness to give R's to the ANG early on, the ANG went to congress with a cheaper alternative. Buy used 707 engines and their engine struts. Very little other modifications were needed. The throttle quadrant was also lifted from the 707's. It did not need the bigger gear or other modifications that accompanied the CFM-56’s. Congress approved and paid for it through a budget supplement (that's the way the ANG gets most of its funding since the DoD rarely funds the ANG sufficiently).

In addition to the ANG flying E’s, many non-associate 135 USAFR units also flew E’s before R’s.

Back to the original question of why no TRs? TRs = weight = less fuel at max gross takeoff. That means less gas for the B-52 carrying the instruments of armageddon. When SAC made tanker procurement decisions, i doubt much (if any) thought was given to if (much less where) the tankers would land if they ever had to accomplish their primary mission. All emphasis was on maximum offload capability. Thus the term Tanker T.O.A.D. : Take Off And Die.

Thanks for all the info folks. That's a LOT of history!!!

Also, US and NATO E3 Sentries used the TF33-PW-100A, a high power version with 21.5K lb of thrust. Saudi, French, and Brit AWACS and Navy E6s used CFM56s.