Chinese Nationalist Air Force & Royal Netherlands East Indies Army Air Force (ML-KNIL)
Operational History by Region
China
Initial Deployment
The prototype was sent to China in 1939 for evaluation.
Curtiss test pilot Bob Fausel claimed a Japanese bomber kill over Chongqing on 4 April 1939.
Chinese Order
China ordered 4 aircraft (including the prototype) and kits for 27 more to be assembled locally by CAMCO at Loiwing.
Combat Use
The three production aircraft were shipped in May 1940.
Intended for use by the Flying Tigers (1st American Volunteer Group) to intercept high-altitude Japanese reconnaissance planes.
Losses
All three aircraft crashed on 23 December 1941 due to poor visibility during a ferry flight from Rangoon to Kunming.
The CAMCO factory was evacuated in 1942 before any of the 27 kits could be assembled.
Dutch East Indies (Indonesia)
CW-21B Variant
Improved version with inward-retracting landing gear and hydraulic flaps.
24 units ordered in April 1940; delivered to Java in early 1941.
Deployment
Assigned to 2-VLG IV Squadron at Andir Airfield, Bandung.
Combat Performance
Engaged Japanese aircraft during the Netherlands East Indies campaign in early 1942.
Claimed four aerial victories.
Challenges
Structural issues grounded several aircraft.
Vulnerable due to lack of armour and self-sealing fuel tanks.
Despite excellent climb rate, most were destroyed in combat or on the ground.
Tactical Strengths & Weaknesses
Rate of Climb
Superior to Japanese Ki-43 and Zero
Manoeuvrability
Good at altitude interception, Poor dog-fighting capability
Armament
Comparable to Ki-43, Inferior to cannon-armed Zero
Durability
Lightweight, agile, Fragile structure, no armour or tank protection
Landing Characteristics
Difficult to land due to long nose
Legacy
Only 62 CW-21s were built in total.
Though limited in combat success, the CW-21 was notable for its export-oriented design philosophy and emphasis on climb performance.
Its operational history reflects the challenges of deploying lightweight interceptors in the harsh realities of WWII air combat.
Variants
Model 21 Interceptor.
One prototype built in 1938.
Three production units and a total of 27 sets of components shipped to the Republic of China to be assembled by CAMCO.
Easily identifiable by the Seversky P-35 type of main undercarriage fairings; 31 built.
Model 21B Interceptor.
A total of 24 built for the Netherlands East Indies, easily identifiable by the inward retracting main landing gear, that eliminated the need for the undercarriage fairings notable on the Model 21.
