Aircraft engine: PZInż. Major Typ 4 (licenced Walter Major)
|Configuration||4-cylinder inverted inline|
|Weight||148 kg (326 lb)|
|Maximum power||120 hp at 2100 RPM|
Czechoslovak Walter Major licence-built by the National Engineering Works at Ursus near Warsaw. It was used in the RWD‑13 aircraft. Production totalled circa 100 examples.
The engine on display was fitted to the RWD‑13 aircraft with the registration SP‑BML, famous for its daring escape from Gdynia, that was being besieged by the Germans, to Sweden on September 14th, 1939. The aircraft was interned in Sweden until the end of the war. In 1952 it had an accident. In 1998 a Swedish pilot, Viking Österlindh donated the surviving engine to the Polish Aviation Museum.