Plenty of pilots (4)
I believe the answer is:
lots
'plenty' is the definition.
(lots of something)
'pilots' is the wordplay.
'LOTS' is hidden in amongst the letters.
But, I'm uncertain how this is indicated.
'of' is the link.
Can you help me to learn more?
(Other definitions for lots that I've seen before include "Large number or amount" , "Oodles" , "Many - items in a sale" , "Large numbers at auction" , "a crowd?" .)