When I file a IFR for a plane, it also gives me estimated fuel used. Is that number accurate? Last I flew a 1200 mile leg on a empty 737. It gave me an estimated fuel usage of 16000lb. So I set up the plane for 20K lb. However, before I got the destination, I ran out of fuel. My question is, how do you know how much fuel you need if that number of the flight planner is not accurate? Also, on the default 737, I could not find the center fuel tank indicator. Did I miss something or it is just not modelled?

The flight planner is out to lunch on est. fuel used. For Jets you plan for your startup, taxi, climb, cruise, approach, missed approach, alternate airport, plus 20 minutes reserve at normal cruise power. Props it is the same but with a 45 minutes reserve. Or atleast that is Canadian regulations. Cheers!

Search the library for "fuel planner." There are several for the Boeings, plus a utility I use called Fuel Calculator 1.1 (by Bryan Samis and Mark Ostheimer) that helps plan consumption for some 120 different aircraft: biz jets, regional jets and commercial jets.You'll still need to plan for taxi, alternate, reserve, weather, etc., but it works well for me (I usually add a little more reserve than it offers).

I'd recommend the FSBuild 2 flight planner from Ernie Alston. I find that it does a great job in fuel calculations, in addition to providing a full flight plan routing and navlog.http://www.fsbuild.com/Regards,Marc