Take off using tail wind on English Channel (6)
I believe the answer is:
deduct
'take off' is the definition.
(I know that take off can be written as deduct)
'tail wind on english channel' is the wordplay.
'tail' indicates one should take the final letters.
'on' means one lot of letters go next to another.
'english' becomes 'e' (abbreviation).
'channel' becomes 'duct' (duct is a kind of channel).
The final letter of 'wind' is 'd'.
'd'+'e'+'duct'='DEDUCT'
'using' acts as a link.
(Other definitions for deduct that I've seen before include "Subtract, take away" , "Withhold" , "Knock off" , "Make a subtraction" , "Remove" .)