Russian airline Kogalymauia Airbus321 recently crashed over Egypt. Before the plane had gone off the radar, the pilot did not request a route change. This was very unusual. Airbus321 split into two in mid-air and the tail end fell onto a sharp rock face. A total of 224 passengers were killed. Both black boxes were recovered, but there is no evidence of what causes this accident. Resources think that a bomb was aboard the plane, but as for now the accident is still under investigation.