Hi John,
Glad that you were able to sort out the missing Directx10 box.
However, if you ever load any default or other add on aircraft and get missing sections or mangled parts scattered on the screen (with or without using Directx10 preview), it's because the developers (Aces Studios), forgot to include an entry in the fsx.cfg file which relates to the high memory requirement of FSX. So if you're interested in that inclusion and would need to use it if this type of problem occurs in the future, this is what you need to do:
a. go to Your Drive (letter) > Users > Your Name > AppData > Roaming > Microsoft > FSX > fsx.cfg
b. open up that file: fsx.cfg (make sure it's not fsx.cfg.txt - amending this one won't effect any changes).
c. after you've opened up fsx.cfg, scroll down to the section entitled: [Graphics].
d. after the last entry under the Graphics section, add this line as I've shown here:
HIGHMEMFIX=1
e. save the file and close.
This entry is a mandatory inclusion and not a Tweak, as many folk tweak other parts of that cfg file. Anyway, keep those details with you, in case you suddenly find strange things happening with your aircraft.
Chris