transport. C-131E Electronic countermeasures (ECM) training version for Strategic Air Command (SAC), later designated TC-131E, 15 built and one conversion from C-131D, two transferred to United States Navy as R4Y-2. TC-131E C-131E redesignated. C-131F R4Y-1 redesignated. RC-131F Conversions for photo-mapping and survey, six conversions. VC-131F R4Y-1Z redesignated. C-131G R4Y-2 redesignated. EC-131G One C-131G modified as an electronics trainer. RC-131G One C-131G modified for airways checking duties. VC-131G C-131G when used as a staff transport. C-131H Conversions to CV-580 turboprop standard. NC-131H One conversion with an extended nose incorporating a separate cockpit as a Total In-Flight Simulator. This aircraft was transferred to the National Museum of the United States Air Force at Wright-Patterson AFB, Ohio on November 7, 2008 R4Y-1 USN/USMC version of CV-340 with 44 passenger seats, redesignated C-131F in 1962, 36 built. R4Y-1Z USN/USMC 24-seat VIP staff transport, redesignated VC-131F in 1962, one built and conversions from R4Y-1. R4Y-2 USN/USMC version of CV-440, redesignated C-131G in 1962, two built and conversions from R4Y-1; an additional 13 canceled, of which six were completed as CV-440 airliners. R4Y-2Q Proposed ECM version of the R4Y-2, five canceled. R4Y-2S Proposed anti-submarine warfare version of R4Y-2, 14 canceled. XT-29 Prototype military trainer version of the Model 240 for the United States Air Force, two built. T-29A Initial production version for navigator training, unpressurized cabin for 14 students, 46 built. VT-29A T-29As converted for staff transport. T-29B Pressurized version with room for 10 navigator and four radio operator students, 105 built. NT-29B One T-29B used for permanent testing. VT-29B T-29B converted for staff transport with seating for 29 or 32 passengers. T-29C T-29B with Pratt & Whitney R-2800-29W engines, 119 built. AT-29C T-29C modified for airways checking duties, redesignated ET-29C in 1962. ET-29C AT-29C redesignated. VT-29C T-29C converted to staff transport. T-29D Bombardier training version of the T-29C with room for six students, 93 built. ET-29D Airways checking conversion of the T-29D. VT-29D Staff transport conversion of the T-29D. XT-29E Proposed turboprop version of T-29B, none built. YT-32 Proposed bomber training version with transparent nose, none built. Operators Paraguayan Air Force operated one former USAF Convair C-131D United States Air Force operated T-29 and C-131 aircraft. United States Navy operated R4Y/C-131 and T-29 aircraft. United States Coast Guard operated R4Y/C-131 aircraft. NASA Surviving aircraft HC-131A 52-5794 – On display at the Pueblo Weisbrod Aircraft Museum in Pueblo, Colorado. C-131A 55-4757 – On display at the