Contact head of development with private land (5,4)
I believe the answer is:
touch down
'land' is the definition.
(touching down is a kind of landing)
'contact head of development with private' is the wordplay.
'contact' becomes 'touch' (touch is a kind of contact).
'head of' indicates taking the first letters.
'with' is a charade indicator (letters next to each other).
'private' becomes 'own' (as in one's own or private belongings).
The initial letter of 'development' is 'd'.
'touch'+'d'+'own'='TOUCH-DOWN'
(Other definitions for touch down that I've seen before include "Land" , "Reach end of flight" .)