Prop Strikes

On Thu, 27 Jan 2005 00:12:02 -0500, "Sam O'Nella"
wrote:

Someone please remind me again why a complete engine teardown is always
necessary afterwards?

I have always been told there are several reasons. One is the
possibility of twisting the crankshaft and having it fracture. So when
they tear it down, it gets magna fluxed to make sure there are no
fractures in it. Second reason is more for the insurance. Because of
issues with the engine possibly being harmed, the insurance company
would rather try and place the blame on someone else if something were
to happen later on. So they require a mechanic to do a complete
inspection, so if something does happen to the aircraft after that,
then they possibly have somewhere else to go; like to the mechanics
insurance saying that the mechanic did not do his job properly. This
will ease the pain from the aircrafts insurance.



Scott D

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Someone please remind me again why a complete engine teardown is
always necessary afterwards?

During a prop strike, the engine is producing power, yet an external
force is suddenly counteracting it. That leads to conflicting
internal forces that can damage crankshafts, retaining bolts (see a
recent Lycoming AD), probably all sorts of moving things.

- FChE

wrote in message
oups.com...
Anyone else here ever experience one? How did yours happen?

Mooney 201 main gear slipped down into a hidden drain while taxying on
grass. The aircraft tipped forward and the prop tip touched the turf. I
still remember the sound. It's a horrible sound... :-(

Julian

wrote in message
oups.com...
Anyone else here ever experience one?

I had one while returning to Boulder City about 3 years
ago. It was early in the afternoon in late May & the winds
were out of the south at about 15 knots. The ride was smooth,
so I didn't expect gusts (big mistake). Landing on the 3 degree
downhill runway 15 with a 7 knot right crosswind was pretty standard,
but during the roll-out while braking hard the wind shifted and
lifted up the left wing. I thought at first I must have scraped the
right wing, but what actually happened is that the plane (182) rotated
about the right main/nose wheel axis sufficiently for the prop tip
to touch the tarmac. Clearing the runway, the automated unicom
was reporting winds as 090@20 with wind shear. The insurance
company (USAIG) were very nice about it & handled the tear-down
& new prop to the tune of about $15K, and without increasing my
premium subsequent years. During the tear-down, discovered
problems with the crank shaft (which may have been caused by
the strike) and some AD's which hadn't been complied with on
the counterweights.

Here's what I learned from that.

1) If it's hot in the desert southwest, always expect wind shear.
Be prepared to adjust the ailerons as necessary & don't just
throw the yoke over to whatever side you think the crosswind
is coming from.

2) Maintain back pressure when on the roll-out especially when
braking hard.

3) Bring up the flaps (they were at 40 degrees) during the
roll-out to make yourself a smaller target for the wind.

On Fri, 28 Jan 2005 02:37:48 GMT, "Tony Cox" wrote in
. net::


Here's what I learned from that.

1) If it's hot in the desert southwest, always expect wind shear.
Be prepared to adjust the ailerons as necessary & don't just
throw the yoke over to whatever side you think the crosswind
is coming from.

Actually, it is more appropriate to "steer" with the wind rather than
into it to minimize its effect. That is, if the aircraft is for
example experiencing wind from the right rear, one would push the
yoke/stick forward and to the left. This lowers the elevator and
right aileron, so that the wind can't get under them as easily.

2) Maintain back pressure when on the roll-out especially when
braking hard.

That's what the POH recommend, IINM.

3) Bring up the flaps (they were at 40 degrees) during the
roll-out to make yourself a smaller target for the wind.

It also puts more weight on the main gear tires to increase brake
effectiveness.

"Larry Dighera" wrote in message
...
On Fri, 28 Jan 2005 02:37:48 GMT, "Tony Cox" wrote in
. net::


Here's what I learned from that.

1) If it's hot in the desert southwest, always expect wind shear.
Be prepared to adjust the ailerons as necessary & don't just
throw the yoke over to whatever side you think the crosswind
is coming from.

Actually, it is more appropriate to "steer" with the wind rather than
into it to minimize its effect. That is, if the aircraft is for
example experiencing wind from the right rear, one would push the
yoke/stick forward and to the left. This lowers the elevator and
right aileron, so that the wind can't get under them as easily.

The problem, of course, is how do you *know* the wind is
coming from the right rear? I was taught to throw the yoke
over when on the ground, but that presupposes that the
wind is still coming from the same direction as when you
were coming down final. I certainly didn't expect the wind
to go from a 30 degree right x-wind to a 90 degree left
x-wind in the time it takes me to roll out! Live and learn,
eh?


2) Maintain back pressure when on the roll-out especially when
braking hard.

That's what the POH recommend, IINM.

Indeed. And I've replaced my previous limp-wristed gentle
tug with something more akin to reigning in a panicked horse!
As I say, live and learn.


3) Bring up the flaps (they were at 40 degrees) during the
roll-out to make yourself a smaller target for the wind.

It also puts more weight on the main gear tires to increase brake
effectiveness.

I've always been nervous touching the flaps on landing. Mainly
because of flight instructors who have cautioned against
unnecessary distractions until clear of the runway and others
who think it establishes a bad habit which may come back to
bite if landing in a retractable (confusing flaps with gear). Not
so nervous now...