Pacific swift or fork-tailed swift 
(Yến hông trắng, Apus pacificus)

The Pacific swift (Apus pacificus) is a species of bird that is part of the Swift family. 
The bird breeds in eastern Asia and is strongly migratory, spending the northern hemisphere's winter in Southeast Asia and Australia. 

The name Apus is Latin for a swift, thought to be a type of swallow with no feet (from Ancient Greek a meaning "without", and pous meaning "foot").
pacificus refers to the Pacific Ocean.