When i delete the default 747, 777 and the 737 all my other model that I downlaod such as a project open sky 747 it's panel turns into a Cessna one. ???
That's because many add-on aircraft do not include a unique panel
but instead alias the panel to one of the default FS9 aircraft.
Check the panel.cfg file in the downloaded aircraft, located in
the "Panel" folder. Chances are it will contain an entry like this:
[fltsim]
alias=fsfsconv\panel.b747-400
or another common one:
alias=fsfsconv\panel.lear45
This is telling FS9 to use the panel located in the aircraft
file named in the alias statement.
You need to either re-install those default aircraft or change the
panel.cfg statement to that of an aircrft with a similar panel
installed.
Paul