We have now released our two swifts that can to us as chicks a few weeks ago. We have hand reared them, until the point where they were ready for release.
If grounded, swifts cannot take off, so its important to get it right and watch over them. We let them take off in a large grassed field, so if they were to crash land, we could retrieve them and they would be shaken, but unharmed. Fortunately they were both excellent flyers and went off into the distance, now free and wild.