Germanwings crash: A chain of problems may have contributed to disaster

Flight 4U9525 from Barcelona to Düsseldorf had reached a cruising altitude of 38,000ft at 10.45am with 150 passengers and crew onboard. The Airbus A320 began an unexplained descent before dropping off radar screens at 10.53am. No distress call was issued and nobody on the Germanwings flight is thought to have survived the crash.