The prototype CW-21 was delivered to China for evaluation by the
Chinese Air Force. The Chinese were impressed by the CW-21's performance, and negotiation started on a Chinese purchase. While these negotiations were ongoing, the CW-21 prototype was flown in combat against Japanese bombers attacking
Chungking, with Curtiss test pilot Bob Fausel claiming a
Fiat BR.20 bomber shot down on 4 April 1939. In May 1939 a contract was signed, with China receiving the prototype and three complete examples built by Curtiss, as well as kits for 27 more aircraft. Assembly would be undertaken by the
Central Aircraft Manufacturing Company (CAMCO) at
Loiwing, near the China-Burma border. These were to be armed with four machine guns: two
.50 caliber (12.7 mm) and two
.30 caliber (7.62 mm).[SUP]
[6][/SUP]The three Curtiss-built aircraft were shipped to China in May 1940 and were eventually handed over to the
1st American Volunteer Group (Flying Tigers), who intended to use them to tackle high-flying Japanese reconnaissance aircraft.[SUP]
[7][/SUP] These crashed and were destroyed, due to poor visibility, on a flight from
Rangoon to
Kunming on 23 December 1941.[SUP]
[8][/SUP] Of the 27 to be assembled by CAMCO, none were completed before CAMCO was forced by advancing Japanese forces to evacuate its Loiwing factory to India in 1942.[SUP]
[9][/SUP]
Curtiss had meanwhile developed an improved version of the CW-21, the CW-21B. The main difference was a new undercarriage with inward-retracting mainwheels and a semi-retractable tail wheel which had been developed for the
Curtiss-Wright CW-23 armed trainer, with other changes including hydraulically operated flaps. Although heavier, the CW-21B was 18 mph (29 km/h) faster than the original CW-21, albeit that climb rate was reduced.[SUP]
[10][/SUP]
In April 1940, the Dutch
Army Aviation Brigade Luchtvaartbrigade, desperate for modern combat aircraft, placed an order for 24 CW-21Bs from Curtiss-Wright. After the
Battle of the Netherlands, which resulted in the Dutch Army surrendering to the invading Germans on 15 May 1940, the order for the CW-21Bs (together with a number of
Curtiss Model 75 fighters and
Curtiss-Wright CW-22 trainers), was transferred to the government of the
Dutch East Indies (now Indonesia), for the
Militaire Luchtvaart van het Koninklijk Nederlands-Indisch Leger ("Military Aviation of the Royal Netherlands East Indies Army"; ML-KNIL).[SUP]
[11][/SUP]
The 24 CW-21Bs were assembled at
Andir airfield,
Bandung,
Java in February 1941, equipping
Vliegtuigroep IV, Afdeling 2 ("Air Group IV, No. 2 Squadron";
2-VLG IV). The lightweight construction of the Curtiss-Wrights gave rise to structural problems, and several aircraft were grounded by cracks in the undercarriage, and were still awaiting repair when
war with Japan began on 8 December 1941.[SUP]
[12][/SUP]
With its light construction, radial engine, low
wing loading, limited pilot protection and lack of
self-sealing fuel tanks, the CW-21B was the Allied fighter most similar to the opposing Japanese fighters. It had a rate of climb superior to the
Nakajima Ki-43 ("Oscar") and
Mitsubishi A6M ("Zero").[SUP][
citation needed][/SUP] The CW-21B had similar firepower to the "Oscar", but worse than the cannon-armed "Zero".
2-VLG IV claimed four aerial victories during the
Netherlands East Indies campaign but the
ML-KNIL was overwhelmed by the sheer number of Japanese aircraft; almost all of its fighters were soon lost in combat or destroyed on the ground.[SUP][
citation needed][/SUP]
After the Dutch East Indies fell, the Japanese acquired a CW-21B, which was used as a liaison aircraft in the SE Asia area. Japanese photos were found showing it at an airfield on Singapore Island.
