After several years of producing flight plans by hand using Notebook I am learning quickly how much faster and more accurately I can produce plans for customized GA traffic using this great software. I have several questions the first of which I will put into this thread. I've noticed that upon saving my flight plans the longitude designator gets changed from W (all my airports are in the Western Hempisphere) to S in the Airportxx.txt file. The Airportxx.txt file is fine when I decompile the traffic file via TTools. What I've had to do is save a copy of my Airport_XX.txt file before bringing up AI Flight Planner so that I don't have to manually change them all back. I then compile the flight plans through TTools. If I don't change all the S's back to W's TTools rejects the Airport file and will not compile the data. Once I change the longitude designator to W, TTools compiles the plans normally and they work fine. I use FS9 and am using the latest AI Flight Planner that I just downloaded and updated this past weekend (1.6.02). I store my Aircraft, Airport, and FlightPlan files in a directory other than where I installed AI Flight Planner. Any thoughts on what is causing this?