Hi Vlad.

It sounds to me like the Avionics is OFF. Make sure that the default FSX flight has the Avionics Master Switch ON. The only time that ever happens to me is if I use the 727 after I have used a plane that has an Avionics Switch and I turn it OFF when shutting down the aircraft. Because the Captain Sim 727 doesn't have an Avionics Master Switch, I have assigned a keyboard shortcut to the Avionics Master Switch. I use CTRL+SHIFT+A.

It is also possible that the battery lost too much power. I added the electric_always_available=1 (under the [electrical] section) in the aircraft.cfg to fix it. Since I started following Lou's instructions on starting the 727, I have removed that line from my 727 aircraft.cfg file.

Hope this helps.

Mark