2023-10-25 UPDATE: Sim Federation has released v1.0.7 of this aircraft, which has fully incorporated this mod into their base package. This mod will no longer be necessary with v1.0.7 and later.
This mod improves and corrects most of the issues with the v1.0.6 release of the Sim Federation Cessna TTX model.
The included README document lists all the changes made in each file modified, and explains the reasoning/need for the changes.
The real world Cessna TTX aircraft is powered by a 310 HP Twin-Turbo Continental TSIO-550-C piston engine,
that operates at a maximum speed of 2600 rpm.
The default Sim Federation model uses an 850 HP Turboprop engine that operates at a maximum speed of 2000 rpm.
The power output and fuel burn rate in this model are excessive for this plane.
To compensate, it appears that Sim Federation doubled the fuel tank size to help offset the loss in usable range.
Also, the default weight and balance configuration provided indicates that the plane is overweight.
However, the empty and max gross weights listed are both significantly lower than the weights stated in the Cessna TTX POH.
This mod corrects the empty and max gross weights shown in the weight and balance table to the POH indcated values.
It revises the default loading to match the example shown in the POH, which is just under the gross weight of 3600 lb.
The CG location has been adjusted to be half-way between the min and max CG limits with 50% fuel.
Full fuel can be used by simply removing the rear passenger weights and increasing the fuel to 100%, and the plane will still be within the min/max CG limits.
The engine remains as a turboprop, but the output has been substantially reduced to match
the take-off, climb, and cruise performance of the real world CESSNA TTX per the POH.
Indicated speed will be 153 KIAS at 70% torque (Normal Cruise).
This will correspond to 186 KTAS at 10,000 ft, 199 KTAS at 15,000 ft, 214 KTAS at 20,000 ft, and 230 KTAS at 25,000 ft.
The air speed indicator ranges have been adjusted to the POH values.
The fuel burn rate has been adjusted to approximately match that of the Continental TSIO-550-C piston engine,
and the fuel tanks have been reduced back to the real Cessna TTX size of 53 gal/tank, 106 gal total (49 gal/tank, 98 gal total usable).
The reduction in power also nearly eliminates the tendency to speed up excessively when taxiing.
The engine controls should be mapped as standard throttle, propeller amd mixture axes,
but the mixture will function the way a condition lever would in a turboprop.
0% mixture is fuel cutoff, 50% mixture is low/ground idle, and 100% mixture is high/flight idle.
There is a moderate increase in torque and NG when switching from low/ground idle to high/flight idle .
Also, moving the throttle into the low detent will apply reverse thrust.
The propeller control doesn't have much effect at ground taxing speeds,
but will allow prop speeds between 1550 rpm (min) and 2000 rpm (Max) during flight.
With these changes this aircraft is a very pleasant and enjoyable experience to fly.
I was unable to locate or determine how to resolve the issue with the reversed flap lever animation.
I emailed Sim Federation twice over the past two weeks about that, and about all of the above mentioned issues.
They never responded.
Hopefully Sim Federation will release an update soon that will correct that.