Prop sync and noise in twins

On May 22, 4:47 pm, Mxsmanic wrote:
John Theune writes:
If you type in prop synch multi-engine planes into the google search
window the first hit you will see is this
The AVSIM Forums - Viewing topic #736 - Prop sync
Out of synch propellers will not be as obvious or as annoying in a
simulator as in a real plane. In most aircraft with prop synch, you
first manually ...
forums.avsim.net/dcboard.php?az=show_topic&forum=189&topic_id=736&m ode=full
- 56k - Cached - Similar pages

Go there , read it and you will know all you want to know.

Thanks. I guess people in the AVSIM forums actually answer questions rather
than just point people to Google.

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

Well **** off there and leave us alone then. You love to tell us how
unhelpful we are then you keep coming back!!! Sounds a lot like a
serious personality disorder right there

Yes... it can be REALLY irritating..

I have a twin engine boat, same issue... VERY annoying.. to me, and
many others..

Some don't seem to mind.. (?)

Not only the noise, but the vibrations , when out of sync, can be very
annoying as well...

Dave



On Mon, 21 May 2007 23:04:57 +0200, Mxsmanic
wrote:

I note that the Baron (and presumably other twins) has a prop sync switch that
somehow synchronizes the prop speeds on both engines. From recordings I've
heard of the interior noise of the aircraft, it does sound as though props
that are just slightly out of sync can produce a very irritating intermittent
noise as they move in and out of phase. Is it very bothersome in real life?
Also, how does the prop sync work? Does it actually move pitch or throttle
levers or something?

"Dave" wrote in message
...
Yes... it can be REALLY irritating..

I have a twin engine boat, same issue... VERY annoying.. to me, and
many others..

Some don't seem to mind.. (?)

Not only the noise, but the vibrations , when out of sync, can be very
annoying as well...

Dave

We had a Cessna 337 on our line for charter use at one time. It had a sync
gauge. Strangely enough, whenever I had occasion to fly this bird I always
ended up syncing the props by ear. You could easily feel if one of them was
out even by a small amount of RPM.
Dudley Henriques

Dudley Henriques wrote:
We had a Cessna 337 on our line for charter use at one time. It had a sync
gauge. Strangely enough, whenever I had occasion to fly this bird I always
ended up syncing the props by ear. You could easily feel if one of them was
out even by a small amount of RPM.


The C-402s I used to fly had a prop syncrophaser but I never knew it to work.
The ear, OTOH, never lied. I never thought it was much of a problem to synch
twins. I'd have to ask my father about how they synched the props in the
Connies and C-54s.



--
Mortimer Schnerd, RN
mschnerdatcarolina.rr.com

Dudley Henriques writes:

We had a Cessna 337 on our line for charter use at one time. It had a sync
gauge. Strangely enough, whenever I had occasion to fly this bird I always
ended up syncing the props by ear. You could easily feel if one of them was
out even by a small amount of RPM.

Logically the smallest differences would also be the most annoying, since they
would result in such slow variations. And in theory you should be able to
eliminate them by adjusting RPM manually. But since the Baron has a prop sync
switch it occurred to me that perhaps the RPM levers aren't precise enough to
make it easy to sync the props (?).

I'm still not clear on whether or not this switch actually moves the prop
levers or what. If it does, it sounds expensive, since it needs an actuator
or servo in the cockpit or along the linkage. If it doesn't, it means that
some of the engine control positions might not accurately reflect the actual
engine settings and that engine settings might not obey the control movements
if prop sync is operating.

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

On May 21, 9:50 pm, Mxsmanic wrote:
Dudley Henriques writes:
We had a Cessna 337 on our line for charter use at one time. It had a sync
gauge. Strangely enough, whenever I had occasion to fly this bird I always
ended up syncing the props by ear. You could easily feel if one of them was
out even by a small amount of RPM.

Logically the smallest differences would also be the most annoying, since they
would result in such slow variations. And in theory you should be able to
eliminate them by adjusting RPM manually. But since the Baron has a prop sync
switch it occurred to me that perhaps the RPM levers aren't precise enough to
make it easy to sync the props (?).

I'm still not clear on whether or not this switch actually moves the prop
levers or what. If it does, it sounds expensive, since it needs an actuator
or servo in the cockpit or along the linkage. If it doesn't, it means that
some of the engine control positions might not accurately reflect the actual
engine settings and that engine settings might not obey the control movements
if prop sync is operating.

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

In the baron I got my multi in, you had to first get the props sync'd
up to within 50 rpm. Then you press the sync button and it fine tunes
the prop governors to get them exact. At least thats how I remember
it, it's been a while. Get a POH, it'll have detailed descriptions of
the system. IIRC Beechcraft POH's are pretty expensive (over $100)

buttman wrote in
oups.com:

On May 21, 9:50 pm, Mxsmanic wrote:
Dudley Henriques writes:
We had a Cessna 337 on our line for charter use at one time. It had
a sync gauge. Strangely enough, whenever I had occasion to fly this
bird I always ended up syncing the props by ear. You could easily
feel if one of them was out even by a small amount of RPM.

Logically the smallest differences would also be the most annoying,
since they would result in such slow variations. And in theory you
should be able to eliminate them by adjusting RPM manually. But
since the Baron has a prop sync switch it occurred to me that perhaps
the RPM levers aren't precise enough to make it easy to sync the
props (?).

I'm still not clear on whether or not this switch actually moves the
prop levers or what. If it does, it sounds expensive, since it needs
an actuator or servo in the cockpit or along the linkage. If it
doesn't, it means that some of the engine control positions might not
accurately reflect the actual engine settings and that engine
settings might not obey the control movements if prop sync is
operating.

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

In the baron I got my multi in, you had to first get the props sync'd
up to within 50 rpm. Then you press the sync button and it fine tunes
the prop governors to get them exact. At least thats how I remember
it, it's been a while. Get a POH, it'll have detailed descriptions of
the system. IIRC Beechcraft POH's are pretty expensive (over $100)

Wow, the modern CFI, waht a mrvel he is.


Bertie

Mxsmanic wrote in
:

Dudley Henriques writes:

We had a Cessna 337 on our line for charter use at one time. It had a
sync gauge. Strangely enough, whenever I had occasion to fly this
bird I always ended up syncing the props by ear. You could easily
feel if one of them was out even by a small amount of RPM.

Logically the smallest differences would also be the most annoying,
since they would result in such slow variations

You're an idiot.

Bertie

Bertie the Bunyip wrote:


You're an idiot.

Bertie

You are one small and unhappy person. Find a hobby.
Cheer yourself up. Life can be better, you know.

On May 22, 9:28 am, Bertie the Bunyip wrote:
Mxsmanic wrote :

Dudley Henriques writes:

We had a Cessna 337 on our line for charter use at one time. It had a
sync gauge. Strangely enough, whenever I had occasion to fly this
bird I always ended up syncing the props by ear. You could easily
feel if one of them was out even by a small amount of RPM.

Logically the smallest differences would also be the most annoying,
since they would result in such slow variations

You're an idiot.

Bertie


And you are the wind beneath our buns. So?