FlyerTalk Evangelist and Ambassador: The British Airways Club
Join Date: Jun 2008
Location: Somewhere between 0 and 13,000 metres high
Programs: AF/KL Life Plat, BA GGL+GfL, ALL Diam, Hilton Diam, Marriott Gold, blablablah, etc
Posts: 33,172
I do think it is about 30 minutes before flight time. I've never asked for a seat block so can't comment on that, but my experience is that if the flight is not full, on an E90, taking a window seat at the back usually gives the highest odds that noone comes next to you.