Complex sentence: Like Medewecki, Offierski built it with Samolot's approval, in their factory in his spare time, beginning in late 1927 after the demise of the ML 2 and using its troublesome air-cooled Anzani engine.
Split into simpler sentences: Like Medewecki, Offierski built it in Samolot's factory in his spare time. He began in late 1927 after the demise of the ML 2, using its troublesome air-cooled Anzani engine.