2 days ago · LONDON, Jan 8 (Reuters) - The latest setback for Boeing's (BA.N) top-selling 737 MAX aircraft occurred on Friday when a panel blew off an Alaska Airlines (ALK.N) plane forcing its pilots to make Most sales are the Max 8, the model involved in both crashes. (There’s also, from smallest to biggest, a Max 7, 9 and 10.) The main operators include Southwest Airlines (31 in the fleet Nc9EDp.