bohica From United States of America, joined Feb 2004, 2555 posts, RR: 0 Reply 2, posted (6 months 1 week 6 hours ago) and read 2585 times:
On the A300/A310, the area behind the rear doors was used for lavatories. The window was there to give passengers a little extra light in that area as well as giving passengers an opportunity to look out of the window while waiting to use one of those lavatories.
On the A330/A340, the galley is located behind the rear doors, so the window was unnecessary. Most of the lavatories were moved to mid-cabin.
Dreadnought From United States of America, joined Feb 2008, 8369 posts, RR: 24 Reply 3, posted (6 months 1 week 1 hour ago) and read 2515 times:
Quoting SXDFC (Thread starter): Coming across many pictures of the Airbus A300/ A310, I have noticed they feature a rear window behind the L4, R4 service door. Why did Airbus feature this window? Was anyone ever seated back there?
I've always wished they had a window in the toilets...
Some aircraft do. LH A340-600 business class lavatory below. I believe SQ's soon to be retired A340-500s also have windows in some lavatories, as do some SAS 737s. Related earlier thread. Windows In Airplane Bathrooms (by KDTWFlyer Jan 21 2005 in Civil Aviation)