Show competitors where to fly a kite? (8)
I believe the answer is:
airfield
'where to fly a kite?' is the definition.
(a kite might be flown in an airfield)
'show competitors' is the wordplay.
'show' becomes 'air' (both can mean broadcast).
'competitors' becomes 'field' (term for those fielded in a competition).
'air'+'field'='AIRFIELD'
(Other definitions for airfield that I've seen before include "Landing strip" , "where flights are on offer" , "If derail? (Anag)" , "Flying base" , "Landing ground" .)