When to replace a prop?

Our Macauley prop was last overhauled (new blades) in 1991. It was
re-sealed and checked by a prop shop in 1997.

It has approximately 2400 hours on it. It's still in spec, doesn't leak,
works fine. Our A&P owned a prop shop in the 1990s, and is very
knowledgeable about these things -- but even he has no hard & fast rule of
thumb for replacement of a prop. He's very much a "condition" guy (and it's
apparently in good condition), but I'm getting nervous about the age of this
thing.

When the heck do you replace a prop?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:

Our Macauley prop was last overhauled (new blades) in 1991. It was
re-sealed and checked by a prop shop in 1997.

It has approximately 2400 hours on it. It's still in spec, doesn't
leak, works fine. Our A&P owned a prop shop in the 1990s, and is very
knowledgeable about these things -- but even he has no hard & fast rule
of thumb for replacement of a prop. He's very much a "condition" guy
(and it's apparently in good condition), but I'm getting nervous about
the age of this thing.

When the heck do you replace a prop?

When it's age makes you nervous.

Happy Flying!
Scott Skylane

I would only replace a prop if it suffered damage or failed to meet
the specifications. The prop on my plane (C-182) was overhauled in
1980 and again in 1996 - my mechanic recommended it due to "Time in
Service" - meaning calendar years since last O/H. The prop shop said
it was in better shape than most of the ones they see. This prop, also
a McCauley, has been basically trouble free.

An overhaul is a lot less expensive than replacement. If that would
buy you peace of mind, go for it!

David Johnson

On Feb 13, 7:38*pm, "Jay Honeck" wrote:
Our Macauley prop was last overhauled (new blades) in 1991. *It was
re-sealed and checked by a prop shop in 1997.

It has approximately 2400 hours on it. *It's still in spec, doesn't leak,
works fine. * Our A&P owned a prop shop in the 1990s, and is very
knowledgeable about these things -- but even he has no hard & fast rule of
thumb for replacement of a prop. *He's very much a "condition" guy (and it's
apparently in good condition), but I'm getting nervous about the age of this
thing.

When the manufactor gets the FAA to approve an AD requiring you
replace it. Otherwise you can just replace parts (blades, hubs, etc).
Most prop shops believe that the Hartzell thing is just the begining
and that within the next 4 years the FAA will ensure that all props
made before 2000 are out of service. The prop manufactors have been
doing a lot of lobbying and want the pre-2000 props out of service for
liability.

-Robert

On Feb 13, 10:45*pm, Clark wrote:
"Robert M. Gary" wrote in news:4303e288-e62a-4708-aee3-
:







On Feb 13, 7:38*pm, "Jay Honeck" wrote:
Our Macauley prop was last overhauled (new blades) in 1991. *It was
re-sealed and checked by a prop shop in 1997.

It has approximately 2400 hours on it. *It's still in spec, doesn't leak
,
works fine. * Our A&P owned a prop shop in the 1990s, and is very
knowledgeable about these things -- but even he has no hard & fast rule
of

thumb for replacement of a prop. *He's very much a "condition" guy (and
it's
apparently in good condition), but I'm getting nervous about the age of
th
is
thing.

When the manufactor gets the FAA to approve an AD requiring you
replace it. Otherwise you can just replace parts (blades, hubs, etc).
Most prop shops believe that the Hartzell thing is just the begining
and that within the next 4 years the FAA will ensure that all props
made before 2000 are out of service. The prop manufactors have been
doing a lot of lobbying and want the pre-2000 props out of service for
cash flow.

-Robert

I corrected the mis-spelling of cash flow as "liability." I'm sure you
meant to spell it correctly and just wanted to be sure it was right.

Or mabye we're 'posed to believe that a prop fatigues out just setting on
the ramp or in a hangar.

--
---
there should be a "sig" here- Hide quoted text -

- Show quoted text -

The scary part is the vast majority don't see this tactic as wrong...
Downright fraud......

The only thing I can see as a concern is if there is corrosion happening
inside the hub or on the roots of the blade. I got rid of mine, very low
time like yours but they were 1983 vintage. Here they are pulled apart
every five years for inspection.

If the prop concerns you, what about the age of the aircraft? ; )

John



Jay Honeck wrote:
Our Macauley prop was last overhauled (new blades) in 1991. It was
re-sealed and checked by a prop shop in 1997.

It has approximately 2400 hours on it. It's still in spec, doesn't
leak, works fine. Our A&P owned a prop shop in the 1990s, and is very
knowledgeable about these things -- but even he has no hard & fast rule
of thumb for replacement of a prop. He's very much a "condition" guy
(and it's apparently in good condition), but I'm getting nervous about
the age of this thing.

When the heck do you replace a prop?

On Feb 14, 7:19 am, The Visitor
wrote:
The only thing I can see as a concern is if there is corrosion happening
inside the hub or on the roots of the blade. I got rid of mine, very low
time like yours but they were 1983 vintage. Here they are pulled apart
every five years for inspection.

If the prop concerns you, what about the age of the aircraft? ; )

John

Jay Honeck wrote:
Our Macauley prop was last overhauled (new blades) in 1991. It was
re-sealed and checked by a prop shop in 1997.

It has approximately 2400 hours on it. It's still in spec, doesn't
leak, works fine. Our A&P owned a prop shop in the 1990s, and is very
knowledgeable about these things -- but even he has no hard & fast rule
of thumb for replacement of a prop. He's very much a "condition" guy
(and it's apparently in good condition), but I'm getting nervous about
the age of this thing.

When the heck do you replace a prop?

For you Americans, FAR 43.13 says this:

(a) Each person performing maintenance, alteration, or preventive
maintenance on an aircraft, engine, propeller, or appliance shall use
the methods, techniques, and practices prescribed in the current
manufacturer's maintenance manual or Instructions for Continued
Airworthiness prepared by its manufacturer, or other methods,
techniques, and practices acceptable to the Administrator, except as
noted in §43.16. He shall use the tools, equipment, and test apparatus
necessary to assure completion of the work in accordance with accepted
industry practices. If special equipment or test apparatus is
recommended by the manufacturer involved, he must use that equipment
or apparatus or its equivalent acceptable to the Administrator.

For us Canucks, CAR 571.02 says something very similar:

571.02 (1) Subject to subsection (2), a person who performs
maintenance or elementary work on an aeronautical product

(b) equivalent to those specified by the manufacturer of that
aeronautical product in the most recent maintenance manual or
instructions for continued airworthiness; or

(c) in accordance with recognized industry practices at the time the
maintenance or elementary work is performed.

The kicker comes in the phrases such as "shall use the
methods, techniques, and practices prescribed in the current
manufacturer's maintenance manual or Instructions for Continued
Airworthiness prepared by its manufacturer" (US) or "shall use the
most recent methods, techniques, practices, parts, materials, tools,
equipment and test apparatuses that are (a) specified for the
aeronautical product in the most recent maintenance manual or
instructions for continued airworthiness developed by the manufacturer
of that aeronautical product" (Canada). These refer to the entire
maintenance manual for that product, and that manual usually has TBOs
listed. For private aircraft, the government here doesn't get too
worried about the six-year/2000 hour life specified for our McCauley
props, but they sure hold us Commercial operators to it. If a
manufacturer has published no spec, it's ten years, in Canada, between
"corrosion inspections," which still means opening the prop.
The prop is easily the most highly stressed part on the
airplane, operating much closer to its limits of strength than the
rest of the airframe might be. Corrosion in the hub, cracking, wear,
or past overspeeding all contribute toward potential and lethal
failure. Throwing a blade is not unheard of, and a lost blade usually
means a lost engine and some serious CG issues immediately afterward.
That said, prop failures make up a tiny minority of aircraft
accidents, I think.

Dan

On Thu, 14 Feb 2008 03:38:18 GMT, "Jay Honeck"
wrote:

When the heck do you replace a prop?

I will replace either my hub or my blades (Hartzell prop) when the prop
shop tells me the item can no longer be overhauled to spec.
--ron

On Feb 14, 6:09*pm, Ron Rosenfeld wrote:
On Thu, 14 Feb 2008 03:38:18 GMT, "Jay Honeck"
wrote:

When the heck do you replace a prop?

I will replace either my hub or my blades (Hartzell prop) when the prop
shop tells me the item can no longer be overhauled to spec.

Likely you will do it next year when the next AD comes out grounding
all Hartzell props made before 2000. Hartzell is actively lobbying the
FAA for this.

-Robert

Dave wrote:

I would only replace a prop if it suffered damage or failed to meet
the specifications. The prop on my plane (C-182) was overhauled in
1980 and again in 1996 - my mechanic recommended it due to "Time in
Service" - meaning calendar years since last O/H. The prop shop said
it was in better shape than most of the ones they see. This prop, also
a McCauley, has been basically trouble free.

An overhaul is a lot less expensive than replacement. If that would
buy you peace of mind, go for it!

David Johnson



Jay's prop is a constant speed prop, which means it is the internal
stuff (wear and corrosion) he's got to worry about. If allowed to go
too far, it could mean a small problem becomes an unrepairable prop.
Also, internal corrosion can lead to a blade separation. Jay, the prop
manufacturers state a 5 or 6 year TBO. You are 3x that. I think it is
time.