How long until prop O/H

[Robert M. Gary]

My Hertzile (?sp?) has almost 900 since its been torn down. I've heard
different things from different mechanics. I know the actual TBO on
the prop is now something like 20,000 hours. However, I don't want to
get stuck somewhere with a problem. How much time do most people here
put on their props?
BTW: I think the last overhaul was about 10 years ago.
-Robert

[Ron Rosenfeld]

On 4 Jun 2004 21:37:26 -0700, (Robert M. Gary) wrote:

>My Hertzile (?sp?) has almost 900 since its been torn down. I've heard
>different things from different mechanics. I know the actual TBO on
>the prop is now something like 20,000 hours. However, I don't want to
>get stuck somewhere with a problem. How much time do most people here
>put on their props?
>BTW: I think the last overhaul was about 10 years ago.
>-Robert

Under Part 91 there is no mandatory overhaul period. However, Hartzell has
a number of different recommended overhaul periods, based on either time in
service or calendar time, depending on the type of propeller and also the
type of service.

Although 900 hours is less than the time in service for most of their
models, ten years is well in excess of the recommended time for most, which
seems to be either five years or six years depending on various factors (at
least for a hub inspection, and probably for the blades, too).

If you call Hartzell with the specifics of your propeller, they should be
able to give you accurate information.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Doug Vetter]

Robert M. Gary wrote:
> My Hertzile (?sp?) has almost 900 since its been torn down. I've heard
> different things from different mechanics. I know the actual TBO on
> the prop is now something like 20,000 hours. However, I don't want to
> get stuck somewhere with a problem. How much time do most people here
> put on their props?
> BTW: I think the last overhaul was about 10 years ago.
> -Robert

I'll echo Ron's response, and add the following.

Our two-blade blade Hartzell CS prop TBO is 2000 hours or 5 years.
That's pretty typical for props of this type. It is highly unlikely any
prop would have a 20000 hr TBO. That sounds more like a life limit to
me. Lower calendar TBOs are specified if the airplane is kept outside.
Call the manufacturer or a good overhaul shop for more information.

When we decided to overhaul our prop at our last annual, it had a bit
under 1000 hours and 24 years (!) since OH. However, cosmetically, it
was in remarkably good shape because the airplane had been hangared for
over half that time. Cost us $1800 from Sensenich Propeller Services
including shipping (our mechanic's airport is only about 50 miles away
from their facility in Lancaster, PA, so they came out in their own truck).

Incidentally, we also decided to have the propeller governor overhauled
at the same time. The flyweight assembly was found to be out of
tolerance and superceeded by a newer part. The governor OH cost $950
with the new assembly.

Not sure whether it's because of the governor or the prop work, but the
prop cycles a bit faster now. You can see the finished work on my site.
Click through:

Aviation->Articles->Maintenance->Annual 2003

-Doug

--
--------------------
Doug Vetter, CFIMEIA

http://www.dvcfi.com
--------------------

[Martin Kosina]

> Although 900 hours is less than the time in service for most of their
> models, ten years is well in excess of the recommended time for most, which
> seems to be either five years or six years depending on various factors (at
> least for a hub inspection, and probably for the blades, too).

I've heard the same thing - if your blades are OK, you may still want
to have the hub re-sealed after more than ten years, that will prevent
corrosion, etc. Its not terribly expensive to do that vs. full blown
overhaul (<<$1000) and it takes care of the moving parts.

If you do overhaul, shop carefuly, the Aviation Consumer had an
article on this while back. Some shops are quite enthusiastic about
rejecting perfectly good blades, apparently.

[Robert M. Gary]

Doug Vetter > wrote in message >...
> Robert M. Gary wrote:
> > My Hertzile (?sp?) has almost 900 since its been torn down. I've heard
> > different things from different mechanics. I know the actual TBO on
> > the prop is now something like 20,000 hours. However, I don't want to
> > get stuck somewhere with a problem. How much time do most people here
> > put on their props?
> > BTW: I think the last overhaul was about 10 years ago.
> > -Robert
>
> I'll echo Ron's response, and add the following.
>
> Our two-blade blade Hartzell CS prop TBO is 2000 hours or 5 years.
> That's pretty typical for props of this type. It is highly unlikely any
> prop would have a 20000 hr TBO. That sounds more like a life limit to
> me. Lower calendar TBOs are specified if the airplane is kept outside.
> Call the manufacturer or a good overhaul shop for more information.

Ok, it sounds like I should at least break open the hub and have it
resealed at next year's annual. The Mooney shop told me that bumping
the TBO to 20,000 really meant that there was no TBO specified for the
prop. However, I'm not sure what problems I'd see before I needed
work. For some things the "don't fix it if it ain't broke" works well.
For others, you could get stuck at some crappy airport in the middle
of no where. I don't want that. :)
At my last annual I opted to have the mags broken open and inspected
rather than overhauled. The mags ended up looking really good and we
opted to not overhaul them. I only ended up spending a few hundred on
the open/close. We did replace some inexpensive parts (like contacts).

-Robert

[Jim Carter]

"Robert M. Gary" > wrote in message
m...
> Doug Vetter > wrote in message
>...
> > Robert M. Gary wrote:
> > > My Hertzile (?sp?) has almost 900 since its been torn down. I've heard
> > > different things from different mechanics. I know the actual TBO on
> > > the prop is now something like 20,000 hours. However, I don't want to
> > > get stuck somewhere with a problem. How much time do most people here
> > > put on their props?
> > > BTW: I think the last overhaul was about 10 years ago.
> > > -Robert
> >
> > I'll echo Ron's response, and add the following.
> >
> > Our two-blade blade Hartzell CS prop TBO is 2000 hours or 5 years.
> > That's pretty typical for props of this type. It is highly unlikely any
> > prop would have a 20000 hr TBO. That sounds more like a life limit to
> > me. Lower calendar TBOs are specified if the airplane is kept outside.
> > Call the manufacturer or a good overhaul shop for more information.
>
> Ok, it sounds like I should at least break open the hub and have it
> resealed at next year's annual. The Mooney shop told me that bumping
> the TBO to 20,000 really meant that there was no TBO specified for the
> prop. However, I'm not sure what problems I'd see before I needed
> work. For some things the "don't fix it if it ain't broke" works well.
> For others, you could get stuck at some crappy airport in the middle
> of no where. I don't want that. :)
> At my last annual I opted to have the mags broken open and inspected
> rather than overhauled. The mags ended up looking really good and we
> opted to not overhaul them. I only ended up spending a few hundred on
> the open/close. We did replace some inexpensive parts (like contacts).
>
> -Robert

Of course then there's the recent thread in this group about the prop that
came "unglued" right after takeoff. The owner was lucky to get back to the
airport if I remember right. I sometimes think TBOs are a concept originally
developed by an advertising department.