Complex sentence: The Savoia-Marchetti SM.81 was an Italian three-engine aircraft, but unlike its contemporary, the Savoia-Marchetti SM.79, it was fitted with a wide range of engines from its introduction.
Split into simpler sentences: The Savoia-Marchetti SM.81 was an Italian three-engine aircraft. Unlike its contemporary, the Savoia-Marchetti SM.79, it was fitted with a wide range of engines from its introduction.