fēi xíng jiǎn chá
unannounced inspection
(sports) out-of-season drug testing; abbr. to 飛檢|飞检[fei1 jian3]
飞
fēi
to fly
行
xíng
(bound form) to walk; to go; to travel
检
jiǎn
to check
查
chá
to research
