I was sorting through my bookmarks this afternoon, having abandoned Opera and gone back to Firefox, and came across this bookmark that Opera had said was dead. I clicked on the off-chance, and was delighted when it came up. Anyway, when I first started flying things like the CS 727 and 707, I was a bit unsure about the speeds and altitudes appropriate to the various portions of the flight. This site provides a profile for all sorts of aircraft on a searchable database.
Aircraft performance database
The link defaults to the BAC1-11 because there is no home page as such, but from there, you can search for other aircraft. Some of the groupings aren't immediately obvious - for instance, the VC-10 doesn't come under airliners, but rather 'military operational aircraft'. It really is one of the most useful flight sim websites I've come across.
Aircraft performance database
Moderators: Guru's, The Ministry