Orders for and deliveries of Boeing jets have plummeted since the planemaker came under scrutiny following two deadly crashes.
After the nuclear deal, Iran hoped to replace more than 200 of its planes. It has only received 11.
The first clues as to what happened on board Flight MS804.
Here's some important background on the tragic crash.
But the physician didn't inform aviation authorities or the airline about Andreas Lubitz's illness, a report has found.