In the early 1920s, the EKW (Eidgenossischen Konstruktion-Werkstatten) company continued to work on improving its creation, the C-3603 attack aircraft. Specifically, the C-3604 variant was developed, featuring a Saurer YS-2 engine with a takeoff power of 1410 hp and a 4-blade constant-speed propeller.
Furthermore, its armament was enhanced: wing-mounted machine guns were replaced by 20mm FF-K 45 cannons, and the bomb load was increased to 600 kg.
Development and Initial Trials
The prototype aircraft (tail number C-601) first flew on August 21, 1944. During testing, it demonstrated a good speed of 560 km/h. Two more prototypes (C-602 and C-603) were built during the winter of 1944-45.
The KTA (Federal Aviation Administration) initially ordered 100 aircraft but later reduced its order to 50. However, the unreliable performance of the engine-propeller unit delayed the aircraft’s final development. The pre-production series of 10 units (C-604-C-613) could only be released between 1947 and 1951. By then, there was no point in continuing production, as the C-3604 was hopelessly outdated.
Operational History and Challenges
The C-3604s entered service with the troops between November 1947 and June 1951, serving in the 17th company. Here, underwing rails for 75mm unguided rockets were installed. The engine problems were never fully resolved, leading to several incidents.
For this reason, aircraft C-604 was lost in an accident on September 19, 1950. Another unit, C-613, crashed while under the disposal of the “Pilatus” aircraft factory. In 1948, aircraft C-606 was used as a tug for the N-20.1 glider, a flying mock-up of Switzerland’s first jet aircraft, the N-20 Aiguillon. All C-3604s were decommissioned on February 17, 1956, and soon after scrapped.
Technical Specifications
| Modification | C-3604 |
| Wingspan, m | 13.70 |
| Length, m | 10.25 |
| Height, m | 3. 60 |
| Wing area, m2 | 28.70 |
| Empty weight | 2840 |
| Normal takeoff weight | 4780 |
| Engine type | 1 Piston engine Saurer YS-2 |
| Power, hp | 1 x 1410 |
| Maximum speed, km/h | 560 |
| Cruising speed, km/h | 475 |
| Practical range, km | 600 |
| Maximum rate of climb, m/min | 750 |
| Practical ceiling, m | 11500 |
| Crew | 2 |
| Armament | three 20-mm cannons FM-K.38 or FF-K 45, three 7.5-mm machine guns MG Browning, bomb load – 600 kg |
Image gallery of the C-3604
