The Fledgling was designed in response to a 1927 Navy requirement for a new primary trainer, and was selected after evaluation in competition with fourteen other submissions.

The Fledgling was a conventional biplane design with two-bay, staggered wings of equal span braced with N-struts.

The pilot and instructor sat in tandem, open cockpits, and the fixed tailskid undercarriage could be easily swapped for a large central pontoon and outrigger floats under the wings for seaplane training.

The Navy ordered two batches of the Fledgling, each powered by different versions of the Wright Whirlwind engine, both of which were built under the Curtiss designation Model 48.

A number of Model 51s were exported to foreign military services for evaluation: four to Canada and one to Czechoslovakia, but these did not lead to any purchases.