Have such gentry arrived at Heathrow? (6)
I believe the answer is:
landed
I'm afraid I can't explain this answer.
Can you help me to learn more?
(Other definitions for landed that I've seen before include "Arrived on shore or tarmac" , "Alit; having estates" , "Arrived on shore or ground" , "having ended the journey by air" , "Came ashore" .)