Type 3-seat reconnaissance seaplane
Engine 1  Lorraine Dietrich 18K
Dimensions Length 11,0 m , height 4,52 m ,  span  15,0 m, wing area 59,5 m2  ,
Weights Empty 2365 kg, loaded  3850 kg, max. take off weight  
Performance Max.. speed 198 km/h , cruising speed  , range 1250 km, endurance  , service ceiling  4500 m , climb
Type Werk.Nr Registration History
A single example built by Heinkel and supplied to Aichi as a pattern aircraft, given the designation Aichi Experimental Three-seat Reconnaissance Seaplane, for possible production in Japan, but was rejected due to problems with the engine and also failure to meet performance and weight reduction targets.
The Heinkel HD 28 was a reconnaissance seaplane developed in Germany in the 1920s for export to Japan. It was a conventional single-bay biplane with equal-span, unstaggered wings and three cockpits in tandem. The fuselage was braced to both the upper and lower wings with a number of struts on its sides, in addition to the normal cabane struts. The rudder extended below the line of the lower fuselage, and there was a large ventral fin fitted. The rearmost cockpit incorporated a ring mount for a gunner.