Free turbine to nominal???

[uhoh7]

The free turbine switch is a 2 position switch, its either in low or nominal; nowhere else. The switch is located on the collective, on the top left side. I have this mapped to my Nav mode on my X52; I use the Hat3 on my throttle/collective to click up or down.

 

Before today, (i just learned that setting this switch to 'low' is the proper way to descend with forward airspeed quickly with lower RPM's) I would use my rotary to lower my throttle levers to lessen RPM's. Don't know if thats a good idea or not....

 

OK, so we know low is for dropping fast. And the switch is two position.

 

Now nominal........we switch back to nominal, then we should have a "cruise" setting and "take off" (guys are using "take off" to get over the mountains)

 

How do we switch from cruise to take off? and back?

 

TY

[Acedy]

How do we switch from cruise to take off? and back?

 

With the throttle levers.

[crazysundog]

gimme a couple minutes Uhoh7, I recorded a clip of what i do in fraps, may help you to understand.... will upload to yt and post back here.

[crazysundog]

Ok, so in this clip I come down the side of a mountain... Notice the first thing i do when i start to gain to much velocity is lower my throttle levers. You can hear the engine wind down, and see my RPM% needle drop.... Of course this may be completely WRONG....it is the way i do it.

 

Next i pull the throttles back up to 'auto' position and hit the RPM switch to the 'low' position on the collective. It doesn't seem to slow my rpms as much.... but oh well...

 

http://www.youtube.com/watch?v=Ek_vLxRGn7I

 

oh, and watch in highquality

[Frederf]

OK, so we know low is for dropping fast. And the switch is two position.

 

Now nominal........we switch back to nominal, then we should have a "cruise" setting and "take off" (guys are using "take off" to get over the mountains)

 

How do we switch from cruise to take off? and back?

 

I would try not to confuse the throttle levers and the Free RPM governor. Throttle is all about engine power and this 2-position free RPM governor switch is about controlling the ERD-3VMA governors and preventing overspeed.

 

I believe the switch on the collective only controls the threshold for power (free) turbine (PT) overspeed. In nominal mode the threshold for overspeed is a function of temperature and pressure. I don't if the low setting is dynamic or just a static value.

[uhoh7]

Ok, so in this clip I come down the side of a mountain... Notice the first thing i do when i start to gain to much velocity is lower my throttle levers. You can hear the engine wind down, and see my RPM% needle drop.... Of course this may be completely WRONG....it is the way i do it.

 

Next i pull the throttles back up to 'auto' position and hit the RPM switch to the 'low' position on the collective. It doesn't seem to slow my rpms as much.... but oh well...

 

http://www.youtube.com/watch?v=Ek_vLxRGn7I

 

oh, and watch in highquality

 

jeez how do we turn those beepers off?????

 

I had my g warning go off first time tonite, hehe

 

TY for taking trouble to record that.

 

I'm hoping somebody will give us the skinny on all this--which way is the right way, when to use auto, nominal, low, when to use throttle settings.

 

I find the manual cryptic on the subject.

[uhoh7]

I would try not to confuse the throttle levers and the Free RPM governor. Throttle is all about engine power and this 2-position free RPM governor switch is about controlling the ERD-3VMA governors and preventing overspeed.

 

I believe the switch on the collective only controls the threshold for power (free) turbine (PT) overspeed. In nominal mode the threshold for overspeed is a function of temperature and pressure. I don't if the low setting is dynamic or just a static value.

 

TY frederf

 

so when should we hit "nominal"?

 

in the manual I came accross this:

 

Engines RPM indicator Takeoff mode – 97% Normal flight – 95% Cruise mode 1 – 93% Cruise mode 2 – 92% Idle – 72…78%

Edited December 22, 2008 by uhoh7