Complex sentence: The energy of this tangential air flow is wasted in a single-propeller design, and causes handling problems at low speed as the air strikes the vertical stabilizer, causing the aircraft to yaw left or right, depending on the direction of propeller rotation.
Split into simpler sentences: The energy of this tangential air flow is wasted in a single-propeller design. The tangential air flow also causes handling problems at low speed as the air strikes the vertical stabilizer, causing the aircraft to yaw left or right, depending on the direction of propeller rotation.