There is indeed a way.
Uninstall TMO. Go into the SH4\MODS\TMO2\Data\Air\ directory. In there, you will see a folder for each aircraft in the game.
Go into each one, and delete the <airplane name>_shp.dds file. For example, go into ADB_B5N2_Kate\ and delete ADB_B5N2_Kate_shp.dds
Once you've deleted all of those, you reinstall TMO, and you should have the standard aircraft icons again. If you decide to run RSRD, you would need to repeat the process for any aircraft included in that mod as well.