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The RWD 14 Czapla (Heron) was an observation aircraft that fought during the German invasion of Poland in 1939, suffering heavy losses, mainly from ground fire.
In 1933 D.W.L. began work on a new reconnaissance and observation aircraft to replace the Lublin R-XIII. Their first design was the RWD 12, a parasol wing monoplane that was similar to the RWD 8 trainer, and was powered by a 220hp Polish Skoda Works J.5 nine-cylinder radial engine. However this aircraft was abandoned at the design stage after the Polish Department of Aeronautics decided that it didn’t meet its requirements.
A new specification was issued for an observation aircraft that was to be powered by the Polish designed 400hp Mors radial engine and with folding wings. D.W.L. produced the RWD 14 to satisfy this requirement, and it went up against the Lublin R-XXI and two designs from P.W.S., the U-6 and Z-7. The D.W.L. design was approved in principle, and an order was placed for three airframes – two flying prototypes and a structural test airframe. Work on these aircraft began in 1934.
The RWD 14 was a parasol wing monoplane. The wing had a constant chord, but was slightly swept back and had slight dihedral on the outer panels. It had Handley Page automatic slots and Slotted differential Frise-type airelons, both of which gave in impressive STOL capabilities. The wings could fold backwards reducing the width of the aircraft to 12ft 9.75in. The fuselage was built around chrome-molybdenum tubes and had an oval cross-section. The forward part was covered with duralumin, the rest with fabric. It was armed with one fixed forward firing 7.7mm KM Wz 33 machine gun and one 7.7mm Vickers F flexibly mounted gun in the rear cockpit.
The first prototype, which was powered by a 420hp Pratt & Whitney Wasp and used steel tubes in the fuselage structure, made its maiden flight in 1935. This aircraft failed to live up to expectations, so a number of changes were made to the second prototype, which was powered by a Mors radial engines and used chrome-molybdenum tubes in the fuselage. This aircraft flew in 1936 and this time met its performance targets. However it was destroyed when the tail assembly failed during diving tests. A third prototype was built, based on the second but with a stronger tail, but this too was lost in a diving accident early in 1937. A series of further changes were made to the tail, which did solve this problem.
Now the aircraft was ready for production, D.W.L. sold the design to the Polish Government. Early in 1938 the Government owned L.W.S. factory was given an order to build 65 RWD 14b aircraft, to be powered by the Mors B and delivered by 28 February 1939. The first of these aircraft began to enter service in March 1939, and by the time the Germans invaded in September 1939 five observation squadrons were equipped with seven aircraft each, twenty aircraft were undergoing maintenance and ten aircraft were in reserve. Each of the five squadrons was allocated to one of the Polish field armies.
In service the RWD 14b’s impressive STOL capabilities were a great boon, allowing it to be used from rough airfields. However many of them were shot down by their own side, often when coming in to land – perhaps unsurprisingly, as most of these units would have suffered heavily from Luftwaffe attacks. However it appears that three times as many RWD 14bs were shot down by Polish fire than by German, an unusually high proportion.
Engine: P.Z.L. G1620B Mors B nine-cylinder radial air-cooled engine
Power: 430hp at sea level, 470hp
Crew: 2
Span: 39ft 0.75in
Length: 29ft 6.75in
Height: 9ft 10.25in
Empty Weight: 2,542lb
Normal Loaded Weight: 3,747lb
Maximum Speed: 153.5mph at sea level, 147.9mph at 6,561ft
Cruising Speed:
Climb rate: 7 min to 6,561ft, 19min to 13,123ft
Ceiling: 16,404ft
Range: 361 miles
Guns: one fixed forward firing 7.7mm KM Wz 33 machine gun and one 7.7mm Vickers F flexibly mounted gun in the rear cockpit