Registered N87589 (c/n UC-1R158), the prototype UCC-1 made the first flight in September 1964 with 180 hp (normally aspirated) Lycoming O-360 engines. In 1966 these were replaced by two similar output fuel injected IO-360-B1Ds and also refinements were made to the engine cowlings and the tail surfaces were slightly increased in area. The production conversions all received the TIO-360 (injection) engines. UCC was later renamed as STOL Aircraft Corporation, and in 1987 the last of 23 aircraft conversions was completed, c/n UC-1R to UC-3R and UC-004 to UC-024 (UC-013 was not built).
RP-C2743 was originally built as N9506U and was first flown by test pilot Peter Annis from the Norwood Massachusetts airport on April 16, 1974. The aircraft was bought by Elpie Paras of the Philippines on a government auction in 2000, after which he restored the aircraft. Registered RP-C2743 the aircraft made its second maiden flight with Philippines' CAA test-pilot Captain Yosalina at the controls from Cagayan de Oro Airport, Lumbia, on February 3, 2004."