Sending communication to team occupying one of the choppers (6)
I believe the answer is:
faxing
'sending communication to' is the definition.
(as in sending a fax)
'team occupying one of the choppers' is the wordplay.
'team' becomes 'xi' (eleven, a football team).
'occupying' indicates putting letters inside.
'one of the choppers' becomes 'fang' (fangs or teeth chop food).
'xi' inserted inside 'fang' is 'FAXING'.
(Other definitions for faxing that I've seen before include "sending document" , "Sending messages electronically" .)