[2] In late 1932, WACO began development of a new type, the Model D, which would be suitable both for use by wealthy private pilots and for military use.
[3][6] This differed from the prototype WHD in having slightly swept wings, a fuller fuselage that tapered less towards the rear, and an enlarged rudder.
[3] Small numbers of military versions followed from 1935, powered by various engines, for several Latin American air forces, with production continuing until 1938.
[9][13] Nicaragua purchased three WHD-As in October 1938,[14] powered by 420 hp (310 kW) Whirlwinds,[10] but one crashed at Belize during delivery, and was replaced by the WHD-A demonstrator in April 1939.
[14] Data from Jane's All the World's Aircraft 1938[5]General characteristics Performance Armament Waco Coding System: [1]