What are condition levers for?

[rightrudder]

Condition levers have different functions in different aircraft. In some (the Dash 8 and DO328, for example) they introduce fuel and cut it off as well as set propeller rpm.

For a good explanation of turbine systems, check out "The Turbine Pilots Flight Manual" by Greg Brown and Mark Holt.

RR

 

[MartinFierro]

I agree I think it depends on the aircraft. I think King Airs and maybe the 1900 have three sets of levers? Maybe not. At any rate, the Saab and others have just 2: power and condition. In the slaab the condition levers don't really change the engine speed (Ng) except for when you unfeather the props. The rest is done with the power levers. With the power levers in the ground idle range and the prop unfeathered, the power levers control the blade angle, which helps controls your thrust for taxi.

 

[chperplt]

In the 1900, we have three sets.. Power, Prop, and Condition. Condition levers are in low or high and control idle N1 speed.

 

[Cornelius]

Can someone explain what the EMB-120 power quadrant is like. There are only two levers and I'm a little confused as to the operation of the levers.

 

[sabreliner]

The function of the condition levers is different on every installation. On the E-120, the position of the levers serves many purposes. They feather the prop, and set the governors to control prop speed in flight. They also actuate the fuel shutoffs.

With the EEC, or Electronic Engine Control,functioning they also serve to govern engine speeds to certain minimum values on the ground. With the condition lever in feather, the engine Nh is governed to a min of 62%. Between Min RPM and Max RPM, the Nh is governed to a min of 50%. At max RPM, the Nh is governed to a min of 65%.

There are several reasons you would want these various values. On the ground, 50% Nh generally provides pleanty of thrust to manuver the airplane in beta range on the power levers. (Beta range being the area below flight idle and above reverse where the power levers directly control prop blade angle.) This lower engine speed allows us to better control the taxi speed without having to use the brakes. Also, on the Brasilia, RPM above 60% on the ground is to be avoided due to some sort of odd prop stress. Wouldn't want to have a prop blade come off at an inopportune moment, nowwould we.

With the condition levers at Max (as they would be for takeoff and landing) you get not only higher prop RPM, but an engine that is already spooled for takeoff, max reverse, or a possible go around, increasing you performance. Having the engine spooled up decreases the engine response time to power lever increases, giving you more instantaneous response.

Like I said earlier, this is one installation, on one airplane. It is bound to be different on many other A/C.

 

[sabreliner]

Cornelius;

Good timing, ehh?!?!

Pure luck. Any questions?

 

[Spiraldive]

Hmm. I've found that the phonetic pronounciation of "condition lever" is the most useful description.

"Air brakes"

 

[Cornelius]

Thanks Sabreliner, I may be assigned the EMB-120 tomorrow, which I just found out today, so I'm doing just a bit of research. The Brasilia sounds like it is going to be a little more demanding than the mighty 1900D. Great explanation.

C-ya

 

[T-handle]

good answer for saab condition levers

Simon Says,

Good simple explanation.

It's too bad that our Mesaba APDs won't take that as an answer on a type rating oral!

 

[Simon Says]

LOL.........I just got back from my PC, that is how I am so hip on this stuff.