包机 is a separable verb (离合词) meaning 'to charter a plane'. The verb 包 ('to charter, to reserve for exclusive use') and the noun 机 ('airplane') can split: you place measure words, modifiers, or duration between them, like 包了一架私人机 ('chartered a private plane'). It can also be used as a noun meaning 'a chartered plane/flight', though the primary POS here is verbal. The object 机 stays at the end in the verb-object construction.