In order to view the full high definition resolution within FSX, you will need to edit your fsx.cfg file and alter the entry:
TEXTURE_MAX_LOAD=4096
If the entry doesn't exist, copy the above and paste it under the [GRAPHICS] section in the fsx.cfg file. Example below:
[GRAPHICS] TEXTURE_MAX_LOAD=4096
NOTE: This value resets to 1024 each time you make ANY adjustments in the FSX DISPLAY settings, so you'll need to reset it back to 4096 if you want the high definition version displayed.
[Installation]
Make sure to install both the HD Jetways AND Airport Parking Spaces available in this package for best effect.
To install the High Definition Jetways Copy the two files named AIR_Jetway2 and AIR_Jetway2_lm in the "High Definition Jetways" folder to your FSX SceneryGlobalTexture folder. Replace the files when asked. In case you would like to revert back to the original files, a backup is located in this package in the "Original Backup Files" folder.
To install the High Definition Airport Parking Spaces Copy the file named AirportParkingSpace in the "High Definition Airport Parking Spaces" folder to your FSXTexture folder. Replace the file when asked. In case you would like to revert back to the original file, a backup is located in this package in the "Original Backup File" folder.