Prop strike effect on resale value?

As others have stated, you need to follow the engine manufacturer's
instructions following a prop strike or "sudden engine stoppage".
Usually this calls for inspection of the crank runout at a minimum. Some
call for engine teardown and magnafluxing parts. Still other engines
require replacement of certain parts like counterweights, camshaft
gears/bolts and other timing gears. I believe it depends on the make and
model of the engine, although others more familiar with this can chime in.

As the fleet ages, trainers especially can be expected to have SOME
damage SOMEWHERE in their history. Proper repairs (as evidenced through
documentation and inspection) and time appear to mitigate any devaluation.

My '74 Cherokee 140 did a ground loop in 1975 at 398 hours since new.
Tore down engine, inspected/replaced all the necessary stuff, replaced
the flaps, stabilitor, and an outer wing skin. Spars checked O.K. All
replacements and skin work flawless (as inspected by several wrenches
over the years). I now have 2600 hours on it.

Will I take one penny off for a 30 year old repair that is invisible,
one whole engine ago, and has withstood the test of time. Nope. And I
will have PLENTY of other buyers who will snap it up if someone insists
on a lower price for the damage history.

Now, a recent prop strike, that is another matter. The opportunity for
hidden or latent damage is quite a bit greater. Eliminate the engine
(via overhaul or replacement), overhaul/inspect the prop, and inspect
the rest of the bird and you probably won't care as much. Don't do those
things and I would personally consider the engine and prop as trash. I
would still insist on a careful inspection of the rest of the bird.

Others may disagree, but it is your money and risk.

Good Luck,
Mike

Mike Spera wrote:
As others have stated, you need to follow the engine manufacturer's
instructions following a prop strike or "sudden engine stoppage".
Usually this calls for inspection of the crank runout at a minimum. Some
call for engine teardown

"Some" includes both Lycoming and Continental.

A recent AD forces the owners of Lycomings to take any sort of
propstrike seriously, as the bolt that holds the gear on the back end
of the crank tends to fail or loosen during a sudden RPM drop. I wonder
if Lycoming will design the next engine with some different means of
retaining that gear...
Here's the AD text. Note Lycoming's definition of "prop
strike."

Dan

2004-10-14 Lycoming Engines (formerly Textron Lycoming): Amendment
39-13644. Docket No. 89-ANE-10-AD. Supersedes AD 91-14-22, Amendment
39-6916.

Effective Date

(a) This AD becomes effective June 25, 2004.

Affected ADs

(b) This AD supersedes AD 91-14-22.

Applicability

(c) This AD applies to

Lycoming Engines (formerly Textron Lycoming),
direct-drive reciprocating engines

(except O-145, O-320H, O-360E, LO-360E, LTO-360E, TO-360-E, O-435, and
TIO-541 series engines).

Unsafe Condition

(d) This AD results from a change to the definition of a propeller
strike or sudden stoppage. The actions specified in this AD are
intended to prevent loosening or failure of the crankshaft gear
retaining bolt, which may cause sudden engine failure.

Compliance

(e) Compliance with this AD is required as indicated before further
flight if the engine experiences a propeller strike after the effective
date of this AD, as defined in paragraphs (i) and (j) of this AD.

(f) Inspect, and if necessary repair, the crankshaft counter bored
recess, the alignment dowel, the bolt hole threads, and the crankshaft
gear for wear, galling, corrosion, and fretting in accordance with
steps 1 through 5 of Lycoming Mandatory Service Bulletin (MSB) No.
475C, dated January 30, 2003.

(g) Remove the existing gear retaining bolt and lockplate from
service, and install a new bolt and lockplate, in accordance with steps
6 and 7 of Lycoming MSB No. 475C, dated January 30, 2003.

Prohibition of Retaining Bolt and Lockplate

(h) Do not install the gear retaining bolt and lockplate that were
removed in paragraph (g) of this AD, into any engine.

Definition of Propeller Strike

(i) For the purposes of this AD, a propeller strike is defined as
follows:
(1) Any incident, whether or not the engine is operating, that
requires repair to the propeller other than minor dressing of the
blades.
(2) Any incident during engine operation in which the propeller
impacts a solid object that causes a drop in revolutions per minute
(RPM) and also requires structural repair of the propeller (incidents
requiring only paint touch-up are not included). This is not restricted
to propeller strikes against the ground.
(3) A sudden RPM drop while impacting water, tall grass, or similar
yielding medium, where propeller damage is not normally incurred.

(j) The preceding definitions include situations where an aircraft
is stationary and the landing gear collapses causing one or more blades
to be substantially bent, or where a hanger door (or other object)
strikes the propeller blade. These cases should be handled as sudden
stoppages because of potentially severe side loading on the crankshaft
flange, front bearing, and seal.

Ron Natalie wrote:
Mike Spera wrote:

As others have stated, you need to follow the engine manufacturer's
instructions following a prop strike or "sudden engine stoppage".
Usually this calls for inspection of the crank runout at a minimum.
Some call for engine teardown


"Some" includes both Lycoming and Continental.

Ron,

I thought they both had that requirement somewhere, but I was not sure
whether it was binding (via some FAA reg.). Some other fellow posted the
AD for one engine make because of the crank gear. That seems to suggest
that the engine manufacturer's "recommendation" did not have regulatory
weight (or the AD would be unnecessary).

What's up?
Thanks,
Mike

On Wed, 23 Nov 2005 02:36:36 GMT, Mike Spera
wrote:

Ron Natalie wrote:
Mike Spera wrote:

As others have stated, you need to follow the engine manufacturer's
instructions following a prop strike or "sudden engine stoppage".
Usually this calls for inspection of the crank runout at a minimum.
Some call for engine teardown


"Some" includes both Lycoming and Continental.

Ron,

I thought they both had that requirement somewhere, but I was not sure
whether it was binding (via some FAA reg.). Some other fellow posted the
AD for one engine make because of the crank gear. That seems to suggest
that the engine manufacturer's "recommendation" did not have regulatory
weight (or the AD would be unnecessary).

I don't have the papers here now, but it came out as an AD. *Any*
prop strike that takes more than a *minor* dressing requires an engine
teardown for both Lycoming and Continental and the engine does not
need to be developing power, or even running when the strike happens.

As to the original question: for most planes as long as the AD had
been complied with there should be no change in price. Now if you had
a nice new Bo, fresh off the assembly line which lost a quarter (or
more) of it's value when you brought it home, that would be an animal
of a different color.

My engine is near run out. If I had to do a tear down after a strike
it'd probably increase the value considerably. :-))

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


What's up?
Thanks,
Mike

Mike Spera wrote:
Ron Natalie wrote:
Mike Spera wrote:

As others have stated, you need to follow the engine manufacturer's
instructions following a prop strike or "sudden engine stoppage".
Usually this calls for inspection of the crank runout at a minimum.
Some call for engine teardown


"Some" includes both Lycoming and Continental.

Ron,

I thought they both had that requirement somewhere, but I was not sure
whether it was binding (via some FAA reg.).

It's not an FAA requirement in most instances. It is however the
manufacturers recommendation in all cases (like TBO).