Overhaul 14 year old prop?

karl gruber wrote:
That's what I said. The guerrilla with the grinder takes off so much
material that it can only be "overhauled" three times.

Twice. Overhaul at 5 years, again at 10 years, and at 15, they're too small to redo.

George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.

On Sat, 24 Sep 2005 02:30:11 GMT, George Patterson
wrote:

karl gruber wrote:
That's what I said. The guerrilla with the grinder takes off so much
material that it can only be "overhauled" three times.

Twice. Overhaul at 5 years, again at 10 years, and at 15, they're too small to redo.

If they need seals, but the blades are in spec why run them through
the grinder?

Mine get a yearly, or when ever needed polishing with 200 grit and
crocus(sp?) cloth to smooth and shine the leading edge. Other than
looking like they need painting after a years flying they rarely ever
need dressing. OTOH you do have to be careful about winter flying with
snow and slush.

When I replaced the 20 some year old, 2-blade prop with a 3-blade the
old one was still well within spec. I don't recall as it had ever been
reshaped, but it had been through several overhauls where the seals
were replaced.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.

On Sat, 24 Sep 2005 02:30:11 GMT, George Patterson
wrote:

karl gruber wrote:
That's what I said. The guerrilla with the grinder takes off so much
material that it can only be "overhauled" three times.

Twice. Overhaul at 5 years, again at 10 years, and at 15, they're too small to redo.

Hmmm. Once upon a time I maintained a bunch of Pt 135 (mandatory
propeller/engine overhaul) airplanes with "Brand H" (5 years BTW for
the ones I am familiar with has changed to 6 years since they started
painting the inside of the hub) compact-hub props.

Blade's leading edges and faces dressed & painted EVERY 100 hours (or
at 50 if they looked really scabby), overhauled every 4-5 years
(happens when you put 400-500 hrs on per year).

Only "new" blades that I had scrapped after repeated o-haul were for
not meeting the min. OD of the blade shank. This shank is required to
be mechanically rolled (reducing the OD) and the roll marks
mechanically removed (reducing the OD further) at each overhaul on
many compact-hub props.

As you've indicated, this occurred typically at the third overhaul,
but technically has nothing to do with somebody randomly grinding
material off of the blades.

Blade grinding is more art than science, and a decent grinder can eval
and remove a minimal amount of material from a blade that has been
properly maintained and repaired. FOD, including repeated operations
from unimproved surfaces (or "hard" water on floatplanes), and
corrosion from improper conversion coating/painting (or not
maintaining the paint/conversion coating) can drastically reduce
blade life (by requiring more material to be removed). But that is NOT
the fault of the guy doing the grinding.

BTW, after one of my employers purchased the prop shop that had been
doing 90% of my propeller work over the years, I gained a lot more
insight into the whole overhaul procedure.

As Mr. Weir had mentioned repeatedly, an AP/IA cannot ground an
aircraft, but this alleged AP/IA could/can/does choose not to perform
an annual inspection on a constant-speed propeller that hadn't been
torn-down, corrosion-inspected, and re-sealed within a 10 year period.

BTW, that practice was in place many years before I had access to a
"company" prop shop.

Regards;

TC

snip

As Mr. Weir had mentioned repeatedly, an AP/IA cannot ground an
aircraft, but this alleged AP/IA could/can/does choose not to perform
an annual inspection on a constant-speed propeller that hadn't been
torn-down, corrosion-inspected, and re-sealed within a 10 year period.

Do you think that's the right way to go?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

On Sun, 25 Sep 2005 03:09:23 GMT, "Jay Honeck"
wrote:

As Mr. Weir had mentioned repeatedly, an AP/IA cannot ground an
aircraft, but this alleged AP/IA could/can/does choose not to perform
an annual inspection on a constant-speed propeller that hadn't been
torn-down, corrosion-inspected, and re-sealed within a 10 year period.

Do you think that's the right way to go?

Yup.

You would need to ask around to find a decent prop shop. Be warned,
there are some out there that will have a ****-fit when they see your
polished blades.

TC

You would need to ask around to find a decent prop shop. Be warned,
there are some out there that will have a ****-fit when they see your
polished blades.

I've got an acquaintance who runs a prop shop in Kissimmee, FL. He seems
like a good guy, and is already aware of my polished prop. I'm considering
sending it off to him -- but, dang, the turn-around time is a killer.

I think I'll wait till January, when the weather really sucks...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

I'm considering
sending it off to him -- but, dang, the turn-around time is a killer.

I think I'll wait till January, when the weather really sucks...

Gonna have to jack up your imagination level Jay. Schedule it in advance so
he's ready for you. Fly down to FL, drop off your plane, help him pull the
prop (for no other reason than a solid education of how it's mounted) then
spend a week hitting all the tourist traps with the family. Spend a couple
days in Winter Haven at http://www.gate.net/~seaplane/ and get your seaplane
rating from a living legend. By the time you're a PPA ASEL/ASES and sick of
Mickey and Donald, your prop will be done and ready to go!

I'd also have him dynamically balance it once installed.

Jim

Spend a couple
days in Winter Haven at http://www.gate.net/~seaplane/ and get your
seaplane
rating from a living legend. By the time you're a PPA ASEL/ASES and sick
of
Mickey and Donald, your prop will be done and ready to go!

Crikey, Jim, my prop overhaul just became a LOT more expensive!

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Gee, Toe, I only said it ONCE, but it sure as hell got repeated enough
times.

Jim


As Mr. Weir had mentioned repeatedly, an AP/IA cannot ground an
aircraft, but this alleged AP/IA could/can/does choose not to perform
an annual inspection on a constant-speed propeller that hadn't been
torn-down, corrosion-inspected, and re-sealed within a 10 year period.