Antonov An-26
An-24T served well in the Soviet Air Force, but arrangement of it's rear hatch had serious shortcomings. Inspired by aircraft such as C-123, Antonov Design Bureau prepared an An-24 derivative with redesigned tail area with cargo ramp (that could be not only opened, allowing vehicles to ride inside, but also slide underneath the fuselage, allowing easy loading of cargo straight from the trucks).
Like the An-24, An-26 served as base for multiple specialized versions, as well as various flying testbeds, laboratories etc. many of which sources are unfortunately too scarce to allow drawing them.
An-26RTR (also RT, RR) - communications retlanslation aircraft, under the same designation an ELINT aircraft was also hidden. Additionaly there was also airborne command post version An-26S, as well as prototype of EW version An-26REP;
An-26 Spasatel (unofficially called "Skalpel") - medical evacuation aircraft with operations room in the forward part of the cabin (2 aircraft);
An-26KPA (commonly called "Kalibrovshchik" - callibrator) - navigation aids callibration aircraft (20 aircraft);
An-26P - firefighting water bomber with two large water tanks on both sides of the fuselage (5 aircraft);
additionaly, Czechoslovak air force converted single An-26 to ELINT version designated An-26Z-1, instantly recognizable by two large fairings below wings.
Some of these planes You already know, but they have been slightly modified.
An-30, An-32 and Chinese Y-7 are to follow soon.
