Curtiss HA

HA

Designed by Capt B L Smith of the US Marine Corps as a two-seat patrol fighter floatplane for use in the Dunkirk-Calais area, the HA - known unofficially as the "Dunkirk Fighter" - was intended to combat the Brandenburg float fighters. The HA was built at the experimental plant of the Curtiss Engineering Corporation. Of conventional wooden construction with fabric skinning, the HA was powered by a 425hp Liberty 12 engine and proposed armament was two synchronized 7.62mm Marlin machine guns and two Lewis guns of the same calibre on a Scarff mounting in the rear cockpit.
The HA was flown for the first time on 21 March 1918, but was found to be unstable longitudinally and seriously tail heavy. The initial test terminated in a crash. Curtiss was then awarded a contract for two further prototypes, the first of which, the HA-1, utilized salvaged components from the original HA and featured revised vertical tail surfaces, an annular-type radiator and relocated wings. The HA-1 demonstrated appreciably improved handling qualities, but was written off after a fire in the air. The third HA prototype, the HA-2, differed appreciably from the HA-1.
The third HA float fighter prototype embodied considerable redesign as the HA-2. Powered by a 12- cylinder Liberty 12 water-cooled engine, like the preceding prototypes, the HA-2 had longer-span wings of marginally increased chord and gap, the upper wing being raised clear of the fuselage, the decking of which was lowered. The radiator was redesigned, but cooling problems were encountered and although the HA-2 proved more docile than the lighter HA-1, it possessed insufficient promise to warrant further development.

HA-1
Take-off weight: 1634 kg / 3602 lb
Empty weight: 1111 kg / 2449 lb
Wingspan: 10.97 m / 35 ft 12 in
Length: 9.37 m / 30 ft 9 in
Height: 3.23 m / 10 ft 7 in
Wing area: 35.95 sq.m / 386.96 sq ft
Max. speed: 203 km/h / 126 mph

HA-2
Take-off weight: 1772 kg / 3907 lb
Empty weight: 1336 kg / 2 lb
Wingspan: 12.80 m / 41 ft 12 in
Length: 9.37 m / 30 ft 9 in
Height: 3.48 m / 11 ft 5 in
Wing area: 45.52 sq.m / 489.97 sq ft
Max. speed: 190 km/h / 118 mph

Curtiss HA-2