Attitude (ATTI) mode is a flight mode in which the drone keeps itself level and holds its altitude but does NOT use GNSS to hold its horizontal position. If the pilot releases the sticks, the aircraft does not stop in place — it drifts with the wind.
Pilots switch to ATTI (or the drone falls into it on its own) when GPS is lost, jammed or spoofed. Flying in this mode demands constant manual correction and a visual reference — eyes on the aircraft, not on the screen.