I believe that the B737 FCC software is written in ADA.
I am not 100% certain of it, but I know that the FCC of the Classic serie (300, 400, 500) was written in ADA, that the FMS of nowadays B737 (NG and MAX) is in ADA, that Collins Aerospace (the FCC subcontractor) works mostly in ADA, and 99% of the B777 code is written in ADA.
Note: I believe that earlier versions of the FCC were written in FORTRAN.
Last edited by Luc Lion; 21st January 2020 at 19:28.