How does a remote pilot land a big fixed wing UAV, whose takeoff weight could be several tons and have to land at a airport with runways? I saw in the TV, these big UAV normally has on-board cameras and its remote pilot work at a station with displays. Is it manual or auto landing? If it is a manual landing, is it similar like manned aircraft pilots to set up the visual contact with the runway and determine the aircraft position in space relative with the runway based on their experience or they have some landing aided system? How they resolve the time delay issue that the image they see thru the onboard camera could be taken seconds ago?
There's a wide range to techniques. In the hobby world, it's much like landing a full-size plane under VFR, you fly a circuit and glide path. Flaps, side-slip, cross-wind, retractable undercarriage, etc can all be used. The difference is that you have to judge the runway centre-line from some distance off to one side, which requires a lot of skill and practice. Also wind-sheer, gusts and unevenness in the runway surface are magnified by the scale. Fortunately the light weight allows models to handle landings that would wreak the full-size.
At the other end of the spectrum, large UAVs can land autonomously, similar to an airliner auto-land, using all the electronic aids of a modern runway.
In the middle are small UAVs, operated away from a runway. Small, slow UAVs can just circle a GPS position with the motor off, gliding until they reach the ground. Faster UAVs fly into nets or a vertical arrestor wire - again autonomously.
For completeness, I should mention that there is a specific branch of model competition for landing on a simulated carrier deck, with an arrestor wire.