Complex sentence: During 1945 the company produced a prototype single-engined light transport, designated the P-4, the P-4 first flew on 22 March 1948 but only one was built.
Split into simpler sentences: During 1945 the company produced a prototype single-engined light transport, designated the P-4. The P-4 first flew on 22 March 1948 but only one was built.