[Franek Grabowski]

There were various versions of the crash at Mapanget, with either pilot stalling the overloaded aircraft in humid and hot air during night take off, or loss of spatial oientation or vertigo by the pilot. This comes from the other pilot, who took off that night.
As far as I know Jan Linden Lipiński's death was unrelated to operations, but I cannot recall the exact source. No information about lost aircraft as well.