Pilot's ordeal (4)
I believe the answer is:
test
I believe this is a double definition.
'pilot's' is the first definition.
(test pilot is a kind of pilot)
'ordeal' is the second definition.
(thesaurus)
(Other definitions for test that I've seen before include "Sample" , "Cricket match; exam" , "See if you can" , "Try, examine critically" , "Trial - international game" .)