Type Single seat fighter
Engine 1 BMW VI 7.3 Z with 2-bladed fixed-pitch propeller
Dimensions Length  7,5 m, height 3,3 m ,  span upper 10,0 m ,lower 8,0 m,  wing area  26,72 m2 ,
Weights Empty 1210 kg, loaded 1630 kg , max. take off weight   fuel 390 l
Performance Max.. speed 322 km/h at sea level,landing speed 95 km/h,  cruising speed  , range , endurance  , service ceiling  8400 m , climb to 3000 m 4,3 min., to 1000 m 1,2 min., to 3000 m 3 min. 54 sec., to 5000 m 9,4 min., to 6000 m 12,0 min.
Armament Provision for 2 machine guns
Type Werk.Nr Registration History
a 326 Built 1929- After testing delivered to USSR, disappointing performance 
a 327 Built 1929
b 344 BL8-1 Built 1930. Delivered to Thailand  as "Bin Khap Lai Type 8" later Type 15 12.01.1930. Withdrawn 1940
b 345 BL8-2 Built 1930. Delivered to Thailand  as "Bin Khap Lai Type 8" later Type 15 15 12.01.1930. Withdrawn 1940
The HD.43 was designed as a further development of the HD.37 from 1928. The HD.37 had been ordered by the Soviet Air Force and was to become their future standard fighter. The Soviet delegation, led by Yakov Alksnis, commissioned some modernizations of the HD.37, which should lead to improved flight characteristics. Two examples, designated HD.43a, were built and tested by Swedish military pilot Nils Söderberg in 1929.

The flight tests at the Research Institute of the Air Force in Moscow began in January 1930. After their completion in the following month, the evaluation surprisingly revealed that the flight characteristics had deteriorated compared to the HD.37 due to the modernization. In the meantime, two more aircraft, designated as HD 43b, were being produced at Heinkel. Only 4 examples of the Heinkel HD 43 were built.

On the 16th of October 1929 the  Royal Siamese Aeronautical Service purchased two Heinkel HD 43b at a price of 107,957 ฿. Both planes whe delivered at the 12th January 1930 and taken into the service as Fighter No. 8. Both planes whe used for the evaluation of the new Fighter against the Bristol Bulldog and Boeing E-100..