by AndersG » Sat Jan 27, 2018 12:42 pm
That means the FDM configuration for the aircraft is out of whack in the version of YASim in your FlightGear. This could have several sources - one is recent code changes in YASim that might have caused changes in behaviour, but it can also be (if the FDM configuration was borderline from the beginning) due to even more subtle changes in floating point processing such as different compiler, compiler options or CPU hardware compared to that of the aircraft author (who presumably didn't put an obviously broken FDM configuration there in the first place).
In either case it is probably not easy to fix without a good understanding of YASim FDM configurations. Double-check that the aircraft version you have is for the version of FlightGear you run.
Callsign: SE-AG
Aircraft (uhm...)
: Submarine Scout, Zeppelin NT, ZF Navy free balloon,
Nordstern,
Hindenburg, Short Empire flying-boat, ZNP-K, North Sea class, MTB T21 class, U.S.S.
Monitor, MFI-9B, Type UB I submarine,
Gokstad ship, Renault FT.