With the growing power of Hitler's Reich in neighboring Germany, the Polish Air Force moved to strengthen its capabilities and this initiative involved a commitment to a new fighter-bomber attack platform. The aircraft would be a multi-engine design and carry a primary attack role with the possibility to reuse the airframe as a heavy bomber interceptor or bomber escort. The multi-role performer would be used to cover several over-battlefield roles by way of a single design - in theory a logistically-friendly route to take and a concept carried by other air powers of the day.
Influenced by the earlier PZL P.37 Los, a twin-engine medium bomber that was soon to enter production, the PZL P.38 'Wilk' ('Wolf') was born (a design credited to Franciszek Misztal). The proposed propulsion scheme included 2 x PZL Foka ('Seal') 8-cylinder inverted-Vee, air-cooled engines and these would be used to drive three-bladed propeller units. A two-man crew, involving a pilot and machine gunner (the latter doubling as the bombardier) would be housed under a Combined cockpit along the midway section of the fuselage. Armament would become a mix of cannon and machine guns while a bomb-carrying / delivery capability would be built in.
Issues (namely overheating and excessive vibration) tied to the development of the proposed Foka engine line meant that a substituted powerplant was required. This led engineers to use U.S.-originated 2 x Ranger SGV-770B 12-cylinder engines of 450 horsepower each. Again these were air-cooled types.
The aircraft was given a traditional arrangement as two-engined fighter-bombers of the period went. As each wing mainplane carried an engine nacelle, the nose assembly was free to accept the primary armament. The fuselage was rounded though with slab-sides giving the aircraft a deep fuselage appearance. The cockpit was aft of the nose assembly and a station at the rear of the fuselage was reserved from a second crewman to man the defensive machine gun weaponry. The gun was positioned to fire between the twin vertical tail planes fitted to the horizontal plane section at the extreme rear of the aircraft. The undercarriage was of a tricycle configuration. The wing mainplanes were straight appendages and rounded at their tips.
Proposed armament was 1 x 20mm FK-A automatic cannon fitted to the nose section and coupled with 2 x 7.92mm PWU wz.36 series machine guns - all of these weapons were fixed and forward-firing. At the rear cockpit was an arrangement of 2 x 7.92mm PWU wz.37 machine guns atop a trainable mounting. The aircraft could also carry up to 660lb of conventional drop stores for bombing sorties.
A pair of prototypes were generated from the two engine selections, the Foka used in the P.38/I and the Ranger used in the P.38/II. The first prototype was eventually equipped with Foka II series engines of 620 horsepower but it was the Ranger-equipped model that recorded a first-flight for the series and this occurred during May of 1938. The aircraft was displayed to the public for the first time during the Paris Air Show that year. P.38/I followed into the air sometime in early-1939. In further testing, the P.38 showed itself to be a heavy aircraft with lackluster performance and able to carry only a nominal bombload. In other words, it held little hope in excelling in any one role.
As the series only ever reached prototype status, estimated true performance specifications included a maximum speed of 289 miles per hour with a range out to 528 miles and a service ceiling up to 30,000 feet. Rate-of-climb was 1,600 feet-per-minute.
By this time (spring of 1939), thinking turned to a more refined form of the same aircraft as the twin-engined P.48 Lampart ('Leopard') equipped with Gnome-Rhone 14M Mars air-cooled radials of 700 horsepower output. However, the German invasion of Poland during September of 1939 ended all hopes for the P.48 project (an incomplete prototype of this design was all that was realized). The two P.38 prototypes themselves ultimate fell to the Germans during the invasion and no more was heard from the pair from then on.
- Ground Attack
- X-Plane / Developmental
27.40 ft (8.35 m)
36.25 ft (11.05 m)
8.20 ft (2.5 m)
4,751 lb (2,155 kg)
6,173 lb (2,800 kg)
289 mph (465 kph; 251 kts)
29,528 feet (9,000 m; 5.59 miles)
528 miles (850 km; 459 nm)
1,600 ft/min (488 m/min)
1 x 20mm FK-A automatic cannon in nose assembly.
2 x 7.92mm PWU wz.36 machine guns in nose assembly.
2 x 7.92mm PWU wz.37 machine guns on trainable mounting in rear cockpit.
Up to 660lb of conventional drop stores held internally.
P.38 'Wilk' - Base Series Designation
P.38/I - First prototype; fitted with Foka/Foka II 8-cylinder air-cooled engines of 490 horsepower each.
P.38/II - Second prototype; fitted with Ranger SGV-770B 12-cylinder air-cooled engines of 450 horsepower each.
P.48 'Lampart' - Advanced development fitted with 2 x Gnome-Rhone 14M Mars radial piston engines of 700 horsepower each; single incomplete prototype.