Complex sentence: Many B.E.2c and B.E.2d aircraft still under construction when the new model entered production were completed with B.E.2e wings-to rationalise the supply of spare parts these aircraft were officially designated as the "B.E.2f" and "B.E.2g".
Split into simpler sentences: Many B.E.2c and B.E.2d aircraft still under construction when the new model entered production were completed with B.E.2e wings. To rationalise the supply of spare parts these aircraft were officially designated as the "B.E.2f" and "B.E.2g".