What a strange feeling! I was sure he had passed way several years ago!
The info bellow was found on Portuguese page Modelismo na Net:
"
The following Notice appeared in the Daily Telegraph for Jan. 6th, 2010, in the Announcements - Deaths column:
GREEN - William, Aviation Author, peacefully with his family at Princess Royal Hospital on 2nd January.
The Notice goes on to say the funeral would be held on Jan. 13th at Beckenham Crematorium - thoughts and wishes to billgreen2010@googlemail.com "
I still have Warplanes of the Third Reich among my "not for sale" books. I guess I tought he had passed way earlier due his retirement from writing...