On Thu, 17 Jul 2008 11:42:20 -0700 (PDT), xyzzy
wrote:

Assuming proper maintanence and a good airframe log/book inspection,
are there any concerns about high time airframes, like insurability,
etc? My partners and I are looking at a warrior with over 11,000
AFTT.

the theoretical concern with high time aluminium aircraft is due to a
property of fatigue in aluminium.
in steel you can subject a component to stresses below a certain
threshold for as long as you like and it will not suffer fatigue.
Aluminium does not have that threshold. all loadings over the life of
the aircraft no matter how small gradually eat into the fatigue life
of the aircraft.

the rub is that 11000 hours doesnt tell you how may pieces of bad
turbulence it has encountered, how many thumper landings it has
suffered, how many times it has been flogged around overloaded, how
many high G manouvers it has enjoyed. so although you know it has done
11000 hours you have no idea how much has been eaten out of the
fatigue life of the aircraft.

our australian authorities are paranoid about this aspect of older
aircraft, however there has never been tinseled aircraft to give
weight to the fears.
the aircraft that have broken up in midair in australia have mainly
been designs like the aerocommander where it has been realised that
the stressing of the bent centre wing joint has substantially
underestimated the actual loads on the spar.

in the case of the warrior, let your eyes be the guide. fatigue leads
to cracking in thin skins and in fittings. does a close visual
inspection show deterioration in stressed areas?

the other problem you'll have is that the design life of the aircraft
was passed many years ago. some aspects of the construction work
against a long life. corrosion in the bare metal in the lap joints in
the skins can be a problem area. dissimilar metals in the wing attach
points can be a problem. areas of poor ventilation down in the flaps
can lead to intergranular corrosion. have a *good* look.

one other thing to consider is where you are going to fly it. if it
has lived 11000hours in the desert, taking it down to the coast and
parking it overnight on the grass will destroy it in quick time no
matter how good it was.

it could be a very good buy or it could be a lemon. only you can
decide this by very careful inspection of all the aircraft.

I was once interested in a warrior that was going at a good price.
I thought it not a good buy but a local LAME (A&P) obviously thought
us a bunch of mugs because he outbid us and got the aircraft.
It never actually returned to flying. in his haste he overlooked the
actual condition of the aircraft and went on the signed off logs.
the aircraft was actually totally shot in subtle ways and was
scrapped.

open your eyes. check it out carefully and have the balls to follow
through with what you decide.
remember, you dont have to buy *this* aircraft.

Stealth Pilot