Adams and Lines-Roberts were killed in a mid-air collision, at about 4 PM, while returning to Merville, from a patrol over Belgium. They crashed in the territory of the village of Nieppe. Correct spelling of the town where they are buried is Armentières. Cité Bonjean is a large WW1 cemetety, with 3 WW2 pilots buried there.
I've organised a visit years ago for the family of Adams (son, grand-son, 2 great-grand-sons).