German airline Lufthansa will again offer free drinks in economy class on short and medium-haul flights this summer on a trial basis, the airline announced on Monday. The decision comes three years after the airline scrapped free drinks in economy class on almost all shorter flights. Lufthansa chief executive Jens Ritter had previously announced the test run in several interviews, in hopes that free drink service may lead to higher customer satisfaction. Selected drinks such as tea or coffee will be available, the airline said on Monday. Customer reactions are to be recorded as part of the ong…