As there was no Simbrief profile for the high quality freeware Felis Tupolev TU-154M and Yakovlev Yak-40 for X-Plane 11 yet, I decided to make one myself, matching the real world values. The profiles are based one the Tupolev TU-154B-2 and the Fokker 70, as these aircraft have almost the same cruising speed and fuel burn, as the Tupolev TU-154M and Yakovlev Yak-40, but I of course adapted it, to match the real aircraft.
TU-154M:
I decreased the fuel factor down to M5 (5 % less than the Tupolev TU-154B-2).
Changelog:
I changed the name from Tupolev TU-154B-2 to Tupolev TU-154M
I adapted the weights to match real world performance values and adjusted the fuel burn
I added the engine type D-30KU-154
I changed the cruising altitude to FL397, which is the maximum ceiling of the Tupolev TU-154M
I edited the Performance Codes, Weight Category, ETOPS Threshold, ETOPS Certification, ICAO Transponder and PBN Capability too, to match the real aircraft
Note: This version is based on the Tupolev TU-154M. Other variants may have different performance values.
Yakovlev Yak-40:
I decreased the fuel factor down to M30 (30 % less than the Fokker 70).
Changelog:
I changed the name from Fokker 70 to Yakovlev Yak-40:
I adapted the weights to match real world performance values and adjusted the fuel burn
I added the engine type AI-25
I changed the cruising altitude to FL230, which is the maximum ceiling of the Yakovlev Yak-40
I edited the Performance Codes, Weight Category, ETOPS Threshold, ETOPS Certification, ICAO Transponder and PBN Capability too, to match the real aircraft