This paper presents the research on the trim characteristics and the controllability for the single-engine failed flight during landing and approaching. First, the dynamic model is established for the single-engine failed flight. Second, The lateral and directional trim characteristics of the single-engine failed aircraft are theoretically analyzed and verified through simulation. Third, the lateral and directional controllability is evaluated by the criteria of CCAR-25 through simulation. In the end, the minimum control speed during landing and approaching is determined according to the trim characteristics aforementioned, and the controllable speed range under low-altitude (9 m–500 m) conditions is calculated for the single-engine failed aircraft.