I flew from Cosmic Air 2 years ago from Delhi to Kathmandu. It was very safe. The only negative thing I can come up, is that the flight was not in time when I left for Kathmandu from Delhi, and returning back to Delhi My flight was at 16:00 but We got the information that the flight was candled at 22:00 It was a Christmas eave, and we got to spend night at Everest hotel. It was fun. I had a connection flight from Delhi on Sunday so luckily I had set my return date 2 days before just in case, otherwise I would have missed my connecting flight. Well It was a long time ago, and things may have changed for good or hopefully not for bad. Good luck anyway.