midair

n.

半空中；上空；

1. The king's face, pale even in the ruddy firelight, seemed to float in midair.
   国王的面容，即使在这火红的火光的映照下，也显得那样苍白，这面孔，似乎漂浮在半空中。

MIDAIR
Midair.
Midair collision avoidance system
Midair collisions enhance saltation
TCAS: A system for preventing midair collisions
Dealing with midair collisions in dense collective aerial systems
Midair collisions: limitations of the see-and-avoid concept in civil aviation.
Posture Detection and Landing Control of a Robot Thrown in Midair
Simulation of the probability of midair interparticle collisions in an aeolian saltating cloud
A model of the trajectories and midair collision probabilities of sand particles in a steady state saltation cloud