In the early 1950s New Zealand topdressing operators were in the U.S. seeking a replacement for war surplus de Havilland Tiger Moths which formed the backbone of the industry.

To answer the New Zealand request US aeronautical engineer and light aircraft enthusiast John W. Thorp, working for the Fletcher Aviation Corporation, conceived the T.15 with design elements taken from his earlier T.11 Sky Scooter including an all-moving horizontal tailplane but with a wing design similar to that of his Fletcher FD-25 Defender.

Prior to production commencing the design was altered to add an enclosed cockpit and more powerful 260 to 310 hp (230 kW) Continental engines.

It was during Air Parts' production that detail improvements and the option of dual controls were added, becoming the FU-24 Mark II.

In the mid 1990s operator Fieldair experimented with a turbocharged small block Chevrolet 402 V-8 producing 550 hp, although the project was cancelled before it flew, and in the early 2000s Super Air flew a Fletcher powered by a 550 hp Ford V-8 diesel which was replaced by a Walter turbine after trials were completed.

[5] In the mid 1970s, Pacific Aerospace decided the Fletcher design was reaching the limits of redevelopment and introduced the larger and stronger PAC Cresco.