The earlier trainer model, designated the T-29, was also based on the Convair 240 and was used to instruct USAF navigators for all USAF aircraft and those USN Naval Flight Officers (NFOs) selected to fly land-based naval aircraft. First deliveries to the USAF were made in 1950 followed by large production quantities until early 1955. The USAF and the USN operated T-29s in separate units at separate locations until 1976. In 1974, the USAF T-29s with the 323d Flying Training Wing (323 FTW) at Mather AFB, California began to be replaced by the Boeing 737-derived T-43. In 1975, the Navy retired all of its T-29s assigned to Training Squadron Twenty-Nine (VT-29) at NAS Corpus Christi, Texas, deactivated VT-29, and merged their advanced navigator training program for land-based NFOs with the Air Force's program at Mather AFB.
A planned bomber training version of the T-29 (designated T-32) was never built. The CV-340 model was used for most C-131Ds.
In addition to T-29 variants, the United States Navy used the Samaritan, initially designated as the R4Y until 1962, at which point the naval aircraft were also redesignated as C-131s.
Nearly all of the C-131s left the active USAF inventory in the late 1970s, but the U.S. Coast Guard operated the aircraft until 1983, while the Air National Guard and U.S. Navy units operated additional C-131 airframes, primarily as Operational Support Aircraft (OSA) for Air National Guard flying wings and as naval air station "station aircraft" until 1990. The C-131 was primarily replaced by the C-9 Nightingale in Regular USAF service, with the Air National Guard replacing their OSA with C-130 Hercules aircraft and the Navy with C-12 Hurons.
A Samaritan was the first aircraft used as a flying gunship testbed in mid-1963, in a program known as "Project Tailchaser". A C-131B (AF Ser. No. 53-7820) was given a gunsight for the side window, but instead of guns it had cameras in the cargo area. Eventually the C-131 was ferried to Eglin AFB in Florida and a General Electric SUU-11A/A 7.62 mm Gatling-style Minigun was installed. Live ammunition was used and both over-water and over-land tests were successful.
Accidents and incidents
On 17 December 1960, a Samaritan crashed at Munich in what is the largest loss of life in an accident in the Bavarian capital. Shortly after takeoff one engine failed and the pilot tried to get back to Riem in heavy fog over Munich. Due to the limited visibility the aircraft struck the tip of St. Paul's church close to the Theresienwiese, and crashed onto a streetcar, killing all 20 people on board the plane, and 32 on the tram.
On 30 April 1983, a C-131 assigned to NAS, Guantanamo Bay, Cuba crashed at Jacksonville NAS with the loss of 13 lives.
A U.S. Coast Guard HC-131A.
Convair T-29A navigational trainer of the U.S. Air Force with four astrodomes above the fuselage
The NC-131H Total-In-Flight Simulator at Wright-Patterson Air Force Base, Ohio
Transport for United States Air Force based on Convair 240, capable of carrying 39 passengers on rearward facing seats or 20 stretchers and 7 seats. 26 built.
Surplus C-131As transferred to the United States Coast Guard, 22 transferred.
Temporary designation used before 1962 when a C-131A was used for medivac duties with 27 stretchers.
Temporary designation used before 1962 when a C-131A was used as a staff transport.
A hybrid Model 240/340 with seats for 48 passengers, 36 built.
C-131B converted for missile tracking, six conversions.
One C-131B used for permanent testing.
C-131B when used as a staff transport.
Two Model 340s flown with Alison 501D-13 engines.
Military version of the Model 340 with seats for 44 passengers, 33 built.
C-131D when used as a staff transport.
Electronic Countermeasures 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.
Conversions for photo-mapping and survey, six conversions.
One C-131G modified as an electronics trainer.
One C-131G modified as an airways aid checking duties.
C-131G used as a staff transport.
Other models converted to Model 580 turboprop standards.