Question on Baron 58 prop control

On the real Baron 58, is there any forward thrust at all with the
props feathered (or set to zero)? I have a slider set to the prop
controls and if I set it to zero the plane will still drift forward
slowly as I advance the throttles.

I'm not clear on exactly what 0% does on the prop control. I notice
that it can actually go into negative percentages, but I have no idea
what that actually does to the props. Does anyone know? Does 0%
actually mean that the prop is feathered? I can see the prop pitch
change out the window, so it seems like it does (the blades are almost
parallel to the wind with props set to zero).

Also, can the props be feathered on a running engine, or is that not a
good thing?

If you are wondering how I got into this, I feathered the props after
simulating a dual engine failure, and forgot to set them back the next
time I started up and taxied out. I noticed the aircraft was
extremely sluggish until it dawned on me that I had not reset the prop
controls.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic wrote:
I'm not clear on exactly what 0% does on the prop control. I notice
that it can actually go into negative percentages, but I have no idea
what that actually does to the props. Does anyone know? Does 0%
actually mean that the prop is feathered? I can see the prop pitch
change out the window, so it seems like it does (the blades are almost
parallel to the wind with props set to zero).

Also, can the props be feathered on a running engine, or is that not a
good thing?

I can't imagine how/why you would feather the prop with the engine
still running. Certainly not something I have or would try. On most all
planes pulling the prop level all the way back feathers them. On some
older planes there was a feather button but nothing I've flown (DC-3,
etc)

-Robert

You can feather the prop on a PT6 free-turbine engine and
this is a normal training and testing procedure. You do
this at idle or very low power settings. On a piston
engine, feathering the prop stops rotation, so the engine
quits.

On a PC game, the electrons stop flowing?


"Robert M. Gary" wrote in message
ps.com...
|
| Mxsmanic wrote:
| I'm not clear on exactly what 0% does on the prop
control. I notice
| that it can actually go into negative percentages, but I
have no idea
| what that actually does to the props. Does anyone know?
Does 0%
| actually mean that the prop is feathered? I can see the
prop pitch
| change out the window, so it seems like it does (the
blades are almost
| parallel to the wind with props set to zero).
|
| Also, can the props be feathered on a running engine, or
is that not a
| good thing?
|
| I can't imagine how/why you would feather the prop with
the engine
| still running. Certainly not something I have or would
try. On most all
| planes pulling the prop level all the way back feathers
them. On some
| older planes there was a feather button but nothing I've
flown (DC-3,
| etc)
|
| -Robert
|

Jim Macklin wrote:
You can feather the prop on a PT6 free-turbine engine and
this is a normal training and testing procedure. You do
this at idle or very low power settings. On a piston
engine, feathering the prop stops rotation, so the engine
quits.

On a PC game, the electrons stop flowing?

I wondered about that. In a turboprop the engine starts with the blades
feathered. However, I don't have the experience to comment on them.

-Robert

Jim Macklin wrote:
You can feather the prop on a PT6 free-turbine engine and
this is a normal training and testing procedure. You do
this at idle or very low power settings. On a piston
engine, feathering the prop stops rotation, so the engine
quits.

On a PC game, the electrons stop flowing?

BTW: My kids got me MSFS X for my B-day. I honestly haven't had the
time to install it. However, my son and I played JetFighter IV
yesterday. Much more fun than MSFS. Not much of a simulator but its fun
learning how to use the different types of air-to-air missles and
air-to-ground bombs/missles/etc. The tactical avionics seems pretty
realistic although I don't have much comparison. The "fire and forget"
missles are much easier than the dumb bombs,.

-Robert

Mxsmanic wrote:
On the real Baron 58, is there any forward thrust at all with the
props feathered (or set to zero)?

There probably is, if only because the feather doesn't turn the blades
completely parallel (it's often 85 - 87 degrees).

Also, can the props be feathered on a running engine, or is that not a
good thing?

Yes, and yes. There is a procedure to check the prop speed mechanism
during run-up to briefly move the prop lever through it's travel.
Intentionally running a prop to feather on an engine doesn't do it any
good, however, and if it gets slow enough, the engine can stall, or
heaven forbid the lock pins can fall in place (and then you're really
FUBAR'd, time for a mechanic). On a (free-turning) turboprop, it's less
of a concern, although I imagine the turbine guys won't thank you for it
if you do it too often.

TheSmokingGnu

"Robert M. Gary" wrote in message
oups.com...

Jim Macklin wrote:
You can feather the prop on a PT6 free-turbine engine and
this is a normal training and testing procedure. You do
this at idle or very low power settings. On a piston
engine, feathering the prop stops rotation, so the engine
quits.

On a PC game, the electrons stop flowing?

I wondered about that. In a turboprop the engine starts with the blades
feathered. However, I don't have the experience to comment on them.

-Robert

As Jim said the PW PT6 engine has no physical connection between the power
section and the drive section. When you turn the prop by hand you are not
turning the engine. Some actually have a prop brake so you can stop the
prop with the engine running to be able to run the accessories (AC and
generator).

The Garret turbine engines are direct drive, they have a driveshaft between
the engine and drive section. When you turn the you are turning the engine.
These engines will not start in the feathered position.

Allen

The PT6 and some other turboprop engines are "free turbines"
with a gas generator section that sends gas to a separate
turbine/gear box assembly. Until the engine develops oil
pressure, the prop is feathered. Other turbine engines, the
Garrett TPE331 being the most common example, has a solid
shaft that drives the prop from the gas section. These
engines are shutdown after locking the prop blades at near
zero pitch, otherwise the loads required to start the engine
would strain the starter motor. In-flight feather and
restarting requires that the prop be manually unfeathered
to restart the engine.

The complications of the TPE331 over the PT6 are a prime
reason the PT6 is the preferred engine by most pilots. The
low cost and slightly high fuel specs make the TPE331 make
it popular with bookkeepers.

http://home.swipnet.se/~w-65189/turb...ne_engines.htm

http://www.pwc.ca/en/3_0/3_0_2/3_0_2_1_1.asp

http://www.aircraftenginedesign.com/TPE331pics.html



"Robert M. Gary" wrote in message
oups.com...
|
| Jim Macklin wrote:
| You can feather the prop on a PT6 free-turbine engine
and
| this is a normal training and testing procedure. You do
| this at idle or very low power settings. On a piston
| engine, feathering the prop stops rotation, so the
engine
| quits.
|
| On a PC game, the electrons stop flowing?
|
| I wondered about that. In a turboprop the engine starts
with the blades
| feathered. However, I don't have the experience to comment
on them.
|
| -Robert
|

Some seaplane props are featherable and reversable so the seaplane can
stop or backup and so the prop can be used as a brake. I believe the
Cessna Caravan in Seaplane config can do this, not sure.

The PT6 engine can be feathered or the blade angle can go to
a reverse setting and the plane can be backed up, as can the
King Air. The prop angle for feathering is about 90 degrees
while normal flight is in the range of 15-45 degrees. Blade
angles less than 15 degrees are called beta and when they
get to 0- [15] degrees they are reverse.

Those numbers are generally correct, but from my memory.
The blade angle is changed when the prop control is pulled
into the reverse range, which is before actually reaching 0
because of forward speed. Pulling the prop control further
spools the engine back into a power range. Reverse is
usually, but not always, locked out in flight. The Pilatus
can be put in reverse in flight as can certain other planes.
But some airplanes that can be reversed in flight are not
safe to do so. A Beech test pilot told me that he had put a
BE E90 in reverse in flight and the airplane did a very fast
flip. On the other hand he also said that the T-tailed King
Airs [f90-200-300] did not do this since the tail was not
blocked by the slipstream. This may or may not be true, it
is just something I was told.
On the ground, dirt ingestion and prop damage are the
limiting factors.



"Doug" wrote in message
oups.com...
| Some seaplane props are featherable and reversable so the
seaplane can
| stop or backup and so the prop can be used as a brake. I
believe the
| Cessna Caravan in Seaplane config can do this, not sure.
|