Why do you have to open the pneumatic crossfeed valves to de-ice the wings? Exactly what does the AC bus cross-tie switch do? And why do the engines only draw fuel from the center tank when all the fuel booster pumps are on? The key to understanding these and many other aspects of your aircraft is studying the schematic drawings for the various aircraft systems. That may sound a little bit dry, but to help you out I have included a Schematics section in the DC-9 Classic Flight Center that gives you live interactive schematic drawings.
Let's take a look at the overhead panel! "Hell yeah!", I hear you say. It is after all the nerve center of the aircraft. Nothing goes in the aircraft until you consult the overhead panel first.
Just recently came across an article on the Internet that detailed the differences between the various DC-9 models, as well as the MD-80 series, the MD-90 and B717. I thought it was a very interesting article and I wanted to share it with you.
"Verdict? Outstanding. Welcome back Espen, we would like to see more of this quality of work from you. There are so many planes from this era that flight simulation developers have forgotten and which would be serious fun were they released with versions of the training center included. I have banged the drum for a high quality payware Constellation in the past, but there are so many other possibilities, starting with a 'Freight Dog' version of the Fokker 50 that Espen cut his teeth on as freeware so long ago. Just go out and buy the Super 80 - I can't think of a better investment to make to while away the months until FSX arrives and when it does, you might just find you like this old plane so much you want to stay with FS2004 until the patch arrives."
Andrew Herd, FlightSim.com reviewer.