Is the Fortran language still being used in aviation?
FORTRAN is not used much that I'm aware of in aviation, but it is significantly used in aeronautical engineering.  I work with people that use Mark Drela's 'xfoil', 'xrotor' and 'aswing' programs on a daily basis for the design and analysis of airfoils, propellers and aerostructures. And I've used the 'CHARM' model of rotorcraft dynamics.  All of these are written in FORTRAN and you often need to know the language to debug them or integrate them into other programs e.g. for global design optimization.