On Sun, 18 Apr 2004 18:17:24 -0700, Jim Weir wrote:

snipped for length, not for content.

On the other hand, they have to pull it apart anyway, so why not just do the
overhaul for the price of a couple of hours of labor and some dollar parts?

Was lucky to have a prop shop next door for a few years, will only add
a few thoughts.

On the older McCauley's, at overhaul, the blades have to be unscrewed
from the ferrules (sp?) and inspected. The longer it has been since
this has been done, the more difficult it is, and the more likely you
are to find problems. The newer McCauley hub designs are stone-simple
and relatively easy to o-haul. The only real down side would be blade
rework/inspection (material removed working toward min specs). I would
agree that on a McCauley in most cases overhaul would be the way to
go.

If you've got a common compact hub Hartzell (not applicable in this
particular case), "overhaul" means they have to roll the blade shanks
near the butt and then polish to remove the roll "marks". There is
also a min. diameter for the blade shanks. As above, there are also
requirements for blade rework (accompanied by another set of min
specs). For 91 operators, I've always recommended a 5 year (max)
tear-down, hub corrosion inspection, and re-seal.

FWIW, there were always a lot fewer scrapped parts coming out of the
McCauley end of the shop than the Hartzell end. Corrosion from
infrequent inspection/improper lubrication being the primary issue.

Never saw a corrosion problem inside the Hartzell props on "working"
airplanes (greased every 100 hrs/2-3 months, o-hauled every 3-4
years). Always thought that a grease job every 100 hrs/6 months
(regardless of hours in the air) would be a good idea for relatively
in-frequent flyers.

TC

snip