Editing Boeing 707 (section)

===707-700===
The 707-700 was a test aircraft used to study the feasibility of using CFM International CFM56 engines on a 707 airframe and possibly retrofitting existing aircraft with the engine. After testing in 1979, ''N707QT'', the last commercial 707 airframe, was restored to 707-320C configuration and delivered to the Moroccan Air Force as a tanker aircraft via a "civilian" order. Boeing abandoned the retrofit program, since they felt it would be a threat to the 757 and 767 programs.<ref name="Bowers445">{{harvnb|Bowers|1989|pp=445, 446}}</ref><ref>The last 707 ''[[Australian Aviation]]'' issue June 15, 1982, page 44</ref> The information gathered from testing led to the eventual retrofitting of CFM56 engines to the USAF C-135/KC-135R models, and some military versions of the 707 also used the CFM56. The Douglas DC-8 "Super 70" series with CFM56 engines was developed and extended the DC-8's life in a stricter noise regulatory environment. As a result, significantly more DC-8s remained in service into the 21st century than 707s.{{citation needed|reason=Paragraph needs citing|date=February 2015}}