The INS were initialized as IFA mode by default and stays in the QUAL: 0.5 OK state and won't continue to work as POS/AINS in the stock Campaign (Both the vanilla version and the supercarrier version). In order to make it work I have to turn back to NAV mode again upon each mission start otherwise the navigation and weapon designation will degrade at unacceptable rate as the flight progress advances. Is it a bug or what is the correct way to work with IFA.