Mr. Fred Naar has been working
extremely hard for over a year now, to develop a
freeware external physics module to simulate such things as, transverse flow, retreating blade stall, and vortex ring state for helicopters in FSX.
He himself was disappointed by the FDE of rotorcraft in the sim, as it is also his favorite type of flying craft to operate.
He most assuredly has a good educational background in physics and mathematics,
not snake oil.
This will be a foundational piece of software, and as important for good rotorcraft simulation, as FSUIPC has become for flight sim overall.
As such, he deserves praise from the community for his steadfast resolve over the past year for developing HTR.
The program calculates the various forces applied to the helicopter at every cycle (update frequency). Each force causes an acceleration on the three axes, it might also cause a torque based on the force application point position in respect of the center of mass. Rotors also cause torques due to the torque applied by the engine.
The forces and relative positions are configured through a config file. I have also included an excel file and a manual to make things easier.
Through the configuration files you can define over 200 parameters that will in turn define the main forces and their interactions, namely: Main Rotor, Tail Rotor, Drag, Gravity, Stabilizers. It is not that difficult to do, and creating a new configuration with testing should not last more than 2-3 evenings. The rotor modeling part is the most complex. Rotor thrust will depend on induced velocity that will in turn depend on rotor thrust and helicopter attitude and velocities.
Power management will then define the power requirement, the necessary power will be supplied by the governor (if present). If power is insufficient (available power will change with altitude, especially for piston engines) this will result in a rotor RPM reduction. In descent, your power need will decrease to a point where autorotative power is sufficient to overcome the other forces, so you can operate a full autorotation without engines.
Fred Naar - From a post at Hovercontrol.com
Simply, real world statisics are plugged into a HTR config file to develop the results. So any of the helicopters available for FSX will be able to have a specific config file created for them.
The forces can then be applied and updated, up to 90 times per second.
I have been using it for about a week now.
I recommend installing the very latest version of FSUIPC, first (registered version not required).
I can say this. The Acceleration EH-101 finally flies right, IMHO, and for the first time since FSX-A release, I actually like flying this helicopter.
The 206 behaves like I have read about.
I really like this addon.
It doesn't make flying a helicopter any harder in FSX, but better.
Seem more stable. More realistic and accurate.
Shows you your bad habits. Makes you a better sim pilot.
Like I said, one thing HTR will not allow is bad habits or heavy hands.
IMHO, you will need to learn to properly transition to and from hovers, to land and take off accordingly, for example.
Heavy landings mean damaged skids and struts.
Quick decents to landing will be rewarded easily with Vortex Ring State and the horror associated with rolling over on your back and plummeting towards the earth out of control in the default Bell 206B. :d
Now, some folks have reported having issues with it on their systems. To me, it's understandable.
I have experienced where the 206 goes into Vortex Ring State 100%, and then back out in about the snap of your fingers.
Keep an open mind.
Please remember, this is Mr. Naar's first development project, and as with new software, it may have some bugs associated with it.
He is aware of these issues and committed to correcting and supporting HTR, as well as developing new config files.
Thank you Fred for such a wonderful thing you have brought to the rotorcraft sim community.
