Complex sentence: If a trailing plane fly's into jet wash it can cause the plane to shake violently and do things, if the wake turbulence is strong enough and the effected aircraft small enough it can flip an aeroplane whilst it is still on the ground.
Split into simpler sentences: If a trailing plane flies into jet wash it can cause the plane to shake violently. If the wake turbulence is strong enough and the effected aircraft small enough it can flip an aeroplane whilst it is still on the ground.