What are condition levers for?

[Jetjr]

Here's a "quick and to the point" answer.

On the Beech 1900 D (PT6) low idle is 68% N1 and High idle is 72% N1. The higher idle will get you faster taxi speeds but the you end up riding the brakes, but the more useful applications are to 1) because the engine is running at a higher rpm, there is less load-stress-heat on the generator when trying to start the second engine, 2) there is better airflow through the engine therefore lower temps inside the engine, 3) the higher rpm helps the Vapor Cycle Machine aka R12 Air Conditioner work better...(Ground ops), 4) the engine responds (spools up) MUCH more quickly from 72%...so you should ALWAYS have your condition lever set to high idle in flight so that you have much better throttle response while maneuvering.

OK....do I win a prize?

 

[F4U]

No doubt about it. Condition Levers and what they actually do are specific to each aircraft.

In the Cessna Conquest the Condition Levers select fuel on or fuel off to the engines, they have no other function as far as the pilot is concerned.

In the Dash on the other hand the Condition Levers do alot of different things.

Provide Fuel On and Fuel Off for engine starting.
Feathers and Unfeathers the Prop.
Used to Set Propeller RPM in the Forward Thrust Range (past the prop min gate)

Changing the Condition Lever Angle between the MIN and MAX postions selects any desired propeller speed between 900 and 1200 rpm. 900 rpms are normally selected for Cruise and 1200 rpms for takeoff, Single Engine Operations, After touchdown to provide for better braking in the discing and reverse regions, and to assist the props in getting rid of sufficient buildups of ice. 1050 rpms is normally used for enroute climb and landings.

 

[Simon Says]

F4U,

Do you fly for Horizon? I ask because of the 900PRPM cruise thing. I thought only Horizon pulls them back that much, or if that is normal with the Dash.

 

[NEDude]

More on aircraft specific condition lever stuff. In the PC-12 you do advance to high idle prior to takeoff. The PC-12 has a virtually identical engine to the Beech-1900D (PT6A-67), but as has been said, in the Beech you do not need the condition levers to be in high idle for flight.

 

[sabreliner]

F4U,

Do you fly for Horizon? I ask because of the 900PRPM cruise thing. I thought only Horizon pulls them back that much, or if that is normal with the Dash.

I don't know if he flies for Horizon or not...

but 900 RPM is the normal cruise setting, at least on the -100, 200 and 300. We would climb usually at 1050, then cruise at 900, though you could also climb at 900 if you really wanted it quiet. The roughly 12ft diameter props on the -100 didn't really need to turn much faster than that.

I flew them at ALG, and PDT also did it the same.

 

[xjcaptain]

Mesaba used the same procedure when we had our dash8-100's. Takeoff was 1200RPM then 900 was used for climb and cruise. About the only time we used 1050 in the climb was in icing conditions. Now we have the Saab's and we only wish we still had the dash-8's!

 

[surplus1]

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

Cornelius,

When you get to GS learn everything you can about the propellers on this aircraft. Remember their limitations and don't exceed them. Don't let anyone make you believe that any of them can be ignored.

This particular aircraft has a history of very serious problems related to its propeller. Learn about them.

I am not trying to scare you, but the propeller problems have been very serious. Reportedly, the biggest one has been "fixed" and I don't know of any recent incidents. Just the same, this propeller on this airframe has killed more than once, so pay attention.

Also, pay close attention to operation in icing conditions. There has been more than one upset due to ice accretion.

Yes, I've flown it and have a lot of time in the aircraft. Despite the problems, it is a fun airplane to fly and I enjoyed it a lot. It's the equivalent of a modern DC-3. Carries the same # of people, twice as high and twice as fast. My second most favorite turboprop and a great little airplane.

PS. If you get about 5 kias slower than the max flap speeds BEFORE you extend the flaps, most of your flap problems will vanish.

You'll have fun when you learn you can pass the "Swedish Helicopter" with one feathered.

 

[Cornelius]

Thanks, I am going to research some of the EMB-120 history next week. I know of the ASA EMB120 prop breakup that was pretty serious. I don't know of any icing accidents it has had. I'll check it out though.

 

[MartinFierro]

I have heard through the grapevine that fairly recently an ASA Brakillya lost control of a prop, it went to 160%. Luckily it was already over the runway and no one was hurt. Cause is still undetermined. This is well after the problem which caused the other ASA Brasilia to go down several years ago was addressed. As for icing, last year or year before I believe a Comair E120 iced up in Florida, lost a lot of altitude and had structural damage. Then if memory serves me, there was another Comair E120 that crashed up north somewhere (possibly CVG?) due to ice.

 

[F4U]

I fly Dash's for CCAir.

How much longer I will be flying Dash's there remains to be seen.

A letter is out indicating we are shutting down on July 1, 2002.