What does a nation do to rebuild an air force following German annexation, war and Soviet occupation in just a few short years (1938-1945)? Well in Czechoslovakia’s case, by 1945 they had aircraft production facilities, numerous German Luftwaffe aircraft and technical plans laying about, such as Messerschmitt Bf 109G/K fighters and immediately after the end of World War Two, operated captured examples and actually built Bf 109G’s as the Avia S-99 from 1945 to 1946 (21 S-99 single seat fighters and 23 CS-99 /Bf 109G-12 two-seat trainers).
A warehouse explosion in Krásné Březno destroyed many Daimler Benz DB 605 inline engines though and lead to a dire shortage of engines to power Bf 109G/S-99 aircraft and a lack of spares to keep them going. This was a significant hurdle to get over to return them to the air!
The Bf 109 was a proven combat success during World War Two but obviously no new replacement engines or parts were going to come from a defeated Germany and the Soviet Union was not quite ready to provide combat aircraft to a former enemy, so Czechoslovakian aeronautical engineers had to come up with an alternative. They needed to find a readily available and powerful enough engine, that was also suitable to be fitted to a relatively small Bf 109 airframe.
The German Junkers Jumo 211F liquid-cooled inverted V-12, 986 kW (1,340 PS – 1322 hp) engine used in bombers such as the Heinkel He 111H, was produced locally as the M-211 and the Avia aero factory began to make modifications to the hard aluminium covered Bf 109 airframe in the Autumn of 1946 to make it fit. The hybri Messerschmitt Bf 109, designated the Avia S-199 was born!
An engine change meant the propellor hub mounted 30mm cannon that was fitted inside the DB 605 engine of the Bf 109G/K was not possible but other armaments were compatible. Therefore the standard S-199 armament consisted of 2 x 13mm MG 131 machine guns above the engine cowling and 2 x MG 151 20mm cannons, one each in underwing gun pods, plus a 250kg bomb payload. Apparently the machine gun synchronization was not always reliable when shooting through the bigger propellor!
On April 25th, 1947 the Avia S-199 rolled out of the Avia factory and took to the sky for the first time. The aircraft was a success and the first deliveries to the Czechoslovakian Air Force began in February 1948. The Avia and Aero aviation company production lines went on to re-engineer and reverse engineer 450 single seat fighters between 1947 and 1951! The top speed of the production aircraft was a respectable 590 km/h.
Avia also produced 82 two-seat training versions, designated the CS-199 (there were armed and unarmed variants). These were developed by re-engineering Messerschmitt Bf 109G-12 two-seat trainers and modifying existing S-199 airframes. The airframe was not lengthened to accommodate the second seat and controls for the instructor but the fuel tank size was reduced (a drop tank was carried under the fuselage to increase the fuel capacity) and the top speed was also reduced to 500 km/h.
Today you can see two rare surviving examples of these Avia aircraft, a S-199 and CS-199 side by side at the Prague Aviation Museum (Kbely) in the Czech Republic. In fact this is the only museum in the world you can see both aircraft together!
I headed out to this absolute treasure trove of a museum in September 2017 and was suitably impressed with the incredible collection of aircraft from both the east and west, dating back to the post World War One era, through World War Two to the Cold War and beyond! I was one of the first people in the gate when they opened and one of the last people to leave. The staff were literally turning the lights off after me (don’t miss the nearby old Aero Factory Complex nearby which is also part of the museum)!
Much of the airframe of the single seat S-199 UF-25 (Serial Number 178) on display in the museum, was luckily rescued from an aircraft dump at Olomouc in 1969. Airframe number 178 was restored in the early 1980’s with parts from numerous other aircraft and today looks like it rolled straight off the Avia production line! It sports the livery and markings of a 1950’s era training unit. At first glance it looks like a late model Bf 109 but you will soon notice the revised shape of the Jumo 211F engine and the more bubble like cockpit canopy.
The two-seat CS-199 UC-26 (Serial Number 565) at the museum is the only surviving Avia example. It was found and saved from a schoolyard in 1966. Who knows what horrors those kids subjected her too whilst out in then open all those years?! The only other variant of a Bf 109G-12 trainer I have seen, is an original Luftwaffe example at RAF Museum Hendon.
The CS-199 was initially taken to the Military Repair Works, then given an overhaul by Avia between 1967 to 1968. Final restoration work was completed by the Kbely museum technicians in 1972. They did a great job! The aircraft is in the livery and markings of the Military Air Academy in Moravia during the late 1940’s and early 1950’s.
Amazingly for a hybrid aircraft which experienced handling difficulties, particularly in landing and when on the ground, due to the less responsive bomber engine and the control difficulties from the high torque created by the wider paddle shaped propellor blades, the Avia S-199 was the standard fighter and the CS-199 the standard trainer of the Czechoslovakian Air Force until the mid 1950’s! Pilot training must have been comprehensive on these characteristics which apparently earnt it the nickname of “Mule”! From 1951 the Czechoslovakian Police Air Force (a paramilitary organisation) also operated 30 S-199 fighters. The last was not retired until 1957 – they were replaced by Soviet supplied jet fighters.
Somewhat ironically, 24 Avia S-199, an aircraft with Nazi German roots, were exported secretly to Israel in 1948, as the nation was under an arms embargo at the time. The S-199 was the first Israel fighter aircraft and was flown by Israeli and foreign volunteer pilots in the fight to defend the foundation of the Jewish state during the 1948 Arab-Israeli War. They were named the “Sakhin” (Knife) and flew with the 101st and 105th Squadrons of the Israel Air Force.
Apparently the engines of Israeli S-199 fighters did not perform well in the desert environment and serviceability issues meant they were soon replaced but the aircraft had some success in expert hands (including former USAAF pilots) against Arab aircraft. One surviving Israeli S-199 (D-112) is on display at the Israeli Air Force Museum.
The S-199 provided a combat aircraft for the Czechoslovakian Air Force but this was the dawning of the jet age and there was another ground breaking German aircraft left behind in Czech territory at the end of World War Two. In my next post I will show you the rare Czechoslovakian Turbina.