I'm going on vacation in Europe, for three weeks ,august 2nd.using one ticket (Lufthansa). but instead of coming back with Lufthansa, on august 20th, I extend my vacation 3 more weeks and coming back with a ticket which I purchase from Turkish air line, good from august 22nd . to September 10th.So, I'm not using the return Lufthansa ticket, and I'm not using the going to Europe ticket , with the Turkish airline, but using the return ticket , Turkish on September 10th.Iknow , I'm losing money ,and I want to know if is possible. This arrangement. best regards
You can't use a return, if you don't take the outbound flight. If you don't show up for any leg of an itinerary, the airline will cancel all remaining flights.
In your case: Not taking the return with Lufthansa is fine.
However, if you don't fly with Turkish on Aug 22, Turkish will cancel your ticket and you can't fly on Sep 10th.