tjh876 wrote on Feb 18^th, 2013 at 12:22am:

I hate to ask, but are these based off real world numbers and experience? -Tom

I'm the one who modified the 200LR airfile and I tested it quite a bit against the Qatar Airways data. You can see my results under the Flight Dynamics section. I used a value of 60 for drag and it is perfect. I also looked at the Continental Flight Manual and they have very slightly higher fps descent than Qatar, but it is also based on the plain -200 and not the ER and LR models. I do not know what data Libretto put in the other airfiles as I did not look at them.

Ben