Complex sentence: After all of the trouble is cleared, it is discovered that the plane crashed due to faulty parts which Hassam and his brother Asif Bin Hassam sold to the people constructing the plane.
Split into simpler sentences: After all of the trouble is cleared, it is discovered that the plane crashed due to faulty parts. It is also discovered that Hassam and his brother sold the faulty parts to the people constructing the plane.