SR71 Blackbird: add fallback model index
Mirage 2000: correct path of fallback model index (/sim/model instead of /sim)
T38: add fallback model index
b29: add fallback model index
Hurricane: add fallback model index
A6M2: add fallback model index
tu154b: add fallback model index
Fokker 70/100: add fallback model index
Citation Bravo: add fallback model index
Yakovlev Yak 18T : Compatibilté HDR/pbr.
