No, but he had a Muslim girlfriend
‘had a Muslim girlfriend. unclear if she was still dating Lubitz at the time of the crash’
http://stthomasaquinasversusnasa.blogspot.com.au/2015/03/muslim-convert-co-pilot-andreas-gunter.html
I don't have any use for Islam, but it's a little far-fetched to see Muslim terrorism behind every act of lunacy in the world. By all accounts, this Lubitz guy had a history of clinical depression (he was institutionalized for treatment, and during his training in Phoenix, AZ, he as briefly barred from flying) and should never have been allowed into the cockpit of a commercial airline from the get-go.