Today's Message Index:
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1. 07:54 AM - Re: Metal Spinning (Ernie)
2. 08:05 AM - Re: Prop Strikes and tear downs (Ernie)
3. 12:01 PM - Re: Re: Prop Strikes and tear downs (Doug Sapp)
4. 12:56 PM - Re: Re: Prop Strikes and tear downs (Roger Baker)
Message 1
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| Subject: | Re: Metal Spinning |
Craig,
What do you mean by "Spinning"? If you need something turned, I have a lathe.
Ernie
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=124347#124347
Message 2
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| Subject: | Re: Prop Strikes and tear downs |
I'm not sure what kind of engine the Lancair has, but many Continental engines
have Nitrited cranks which are stong but as brittle as glass, so yes I would always
tear down any flat engine after a prop strike. My old J-58 Bonanza prop
suffered a collision with a towbar which was still attached (Dont ask) and when
I tore the engine down the crank was cracked.
That said, the overhaul manual for the Husai engine says in so many words.
"If the prop strike wasnt a "Sudden Stoppage", and the damage is located more than
3 feet (more or less, I dont remember the exact dimension), from the center
axis of the4 hub (about 6 inches in from the wing tip) then just replace the
prop. I've heard of people doing "Run Out" checks on our round engines. This
proves nothing. If the engine was idleing, and you landed on grass or sand, and
the prop kept turning, and the blades showed no signs of gross impact (missing
metal etc) and the bend occurs beyond the manual specs, then you are probably
ok to just replace the prop. Otherwise a teardown is warranted.
Ernie
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=124349#124349
Message 3
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| Subject: | Re: Prop Strikes and tear downs |
Guys,
Would you put your wife or children in a aircraft that was "probably"
OK? For that matter would you fly it your self? Next time you take a
buddy flying tell him/her that "ya it had a prop strike, but it's
probably OK", and watch the reaction. If they are smart they will run
like hell. After owning one of the major aircraft salvage companies in
the US for nearly 20 years (Aircraft Salvage and Rebuild Inc) and
salvaging over 1000 aircraft, I think I have seen nearly every type of
accident, from hand propping to wind damage, from bad external loads to
cruising full tilt into a cloud full of mountain. I have seen prop
flanges break off, mag gear shafts break, gears loose teeth, lock pins
and keepers come loose, cylinders come completely off the engine. I
have seen "homemade mods" come loose causing all sorts of havoc, exhaust
with holes which caused engine fires, the list is long but in most
instances can be traced back to something we could have prevented if we
had not put our wallets in front of our good judgment.
Recently as most of you know I had a engine failure where in all three
of the planetary gears in the nose case failed and all power was lost.
This accident was felt by all who inspected the engine to be the result
of a prop strike somewhere in the aircrafts distance past. True the
engine installed on this aircraft came from China "used" but it is no
different than me buying a stateside aircraft that had had a
undocumented prop strike in it's past. If you sell your aircraft what
is your obligation to the guy who buys it? Did you note the prop strike
in the logs so he can make an informed decision? Most owners hesitate
to do so because they feel that it lessens the resale value of the
aircraft, but that's a topic for future posts. Guy's, we have enough
problems to worry about without having to worry about rather the engine
has been damaged internally after a prop strike, so believe me when I
say that you simply rolling the dice, maybe you will and maybe you
won't, maybe it will run 5 hours maybe it will run 500 hours. If you
have had a prop strike I do not believe that you can honestly look me in
the eye and tell me that you feel good enough about your engine to load
your love ones up and go flying. It always amazes me that when we ARE
fully insured the prop strikes are always worse than when we ARE NOT
insured. Yes, some have gotten away with doing nothing but changing the
prop but folks, it simply is NOT worth the chance, and money in this
instance should not be part of the equation, if it is maybe you should
look again at rather or not you can afford to own this type of
aircraft. If you cannot afford to install a fresh engine at the minimum
send the prop struck engine out for tear down and inspection. Then put
the engine on a 5 to 10 hour oil change with oil analysis at each
change, and watch it like your life depends on it, because it just
might.
Always Yakin,
Doug
Ernie wrote:
>
>I'm not sure what kind of engine the Lancair has, but many Continental engines
have Nitrited cranks which are stong but as brittle as glass, so yes I would
always tear down any flat engine after a prop strike. My old J-58 Bonanza prop
suffered a collision with a towbar which was still attached (Dont ask) and when
I tore the engine down the crank was cracked.
>
>That said, the overhaul manual for the Husai engine says in so many words.
>
>"If the prop strike wasnt a "Sudden Stoppage", and the damage is located more
than 3 feet (more or less, I dont remember the exact dimension), from the center
axis of the4 hub (about 6 inches in from the wing tip) then just replace the
prop. I've heard of people doing "Run Out" checks on our round engines. This
proves nothing. If the engine was idleing, and you landed on grass or sand,
and the prop kept turning, and the blades showed no signs of gross impact (missing
metal etc) and the bend occurs beyond the manual specs, then you are probably
ok to just replace the prop. Otherwise a teardown is warranted.
>
>Ernie
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=124349#124349
>
>
>
>
Message 4
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| Subject: | Re: Prop Strikes and tear downs |
Doug is, as always, a voice of reason and experience...saying things
to which we should pay attention.
I recently happened to be looking directly at a CJ when the pilot had
a "brain fart" and raised the gear lever. He didn't raise the gear,
but he certainly lowered the airplane. To the point; the airplane
was parked and the engine was at idle....but when the one blade
struck the ground, the convulsion that the rest of the airplane went
through gave graphic evidence of the enormous forces that are working
inside the engine...even at idle.
Thanks Doug.
Roger_____________________________________________________________
On Jul 17, 2007, at 11:57 AM, Doug Sapp wrote:
>
> Guys,
> Would you put your wife or children in a aircraft that was
> "probably" OK? For that matter would you fly it your self? Next
> time you take a buddy flying tell him/her that "ya it had a prop
> strike, but it's probably OK", and watch the reaction. If they are
> smart they will run like hell. After owning one of the major
> aircraft salvage companies in the US for nearly 20 years (Aircraft
> Salvage and Rebuild Inc) and salvaging over 1000 aircraft, I think
> I have seen nearly every type of accident, from hand propping to
> wind damage, from bad external loads to cruising full tilt into a
> cloud full of mountain. I have seen prop flanges break off, mag
> gear shafts break, gears loose teeth, lock pins and keepers come
> loose, cylinders come completely off the engine. I have seen
> "homemade mods" come loose causing all sorts of havoc, exhaust with
> holes which caused engine fires, the list is long but in most
> instances can be traced back to something we could have prevented
> if we had not put our wallets in front of our good judgment.
> Recently as most of you know I had a engine failure where in all
> three of the planetary gears in the nose case failed and all power
> was lost. This accident was felt by all who inspected the engine
> to be the result of a prop strike somewhere in the aircrafts
> distance past. True the engine installed on this aircraft came
> from China "used" but it is no different than me buying a stateside
> aircraft that had had a undocumented prop strike in it's past. If
> you sell your aircraft what is your obligation to the guy who buys
> it? Did you note the prop strike in the logs so he can make an
> informed decision? Most owners hesitate to do so because they feel
> that it lessens the resale value of the aircraft, but that's a
> topic for future posts. Guy's, we have enough problems to worry
> about without having to worry about rather the engine has been
> damaged internally after a prop strike, so believe me when I say
> that you simply rolling the dice, maybe you will and maybe you
> won't, maybe it will run 5 hours maybe it will run 500 hours. If
> you have had a prop strike I do not believe that you can honestly
> look me in the eye and tell me that you feel good enough about your
> engine to load your love ones up and go flying. It always amazes
> me that when we ARE fully insured the prop strikes are always worse
> than when we ARE NOT insured. Yes, some have gotten away with
> doing nothing but changing the prop but folks, it simply is NOT
> worth the chance, and money in this instance should not be part of
> the equation, if it is maybe you should look again at rather or not
> you can afford to own this type of aircraft. If you cannot afford
> to install a fresh engine at the minimum send the prop struck
> engine out for tear down and inspection. Then put the engine on a
> 5 to 10 hour oil change with oil analysis at each change, and watch
> it like your life depends on it, because it just might.
> Always Yakin,
> Doug
>
> Ernie wrote:
>
>>
>> I'm not sure what kind of engine the Lancair has, but many
>> Continental engines have Nitrited cranks which are stong but as
>> brittle as glass, so yes I would always tear down any flat engine
>> after a prop strike. My old J-58 Bonanza prop suffered a collision
>> with a towbar which was still attached (Dont ask) and when I tore
>> the engine down the crank was cracked.
>>
>> That said, the overhaul manual for the Husai engine says in so
>> many words.
>>
>> "If the prop strike wasnt a "Sudden Stoppage", and the damage is
>> located more than 3 feet (more or less, I dont remember the exact
>> dimension), from the center axis of the4 hub (about 6 inches in
>> from the wing tip) then just replace the prop. I've heard of
>> people doing "Run Out" checks on our round engines. This proves
>> nothing. If the engine was idleing, and you landed on grass or
>> sand, and the prop kept turning, and the blades showed no signs of
>> gross impact (missing metal etc) and the bend occurs beyond the
>> manual specs, then you are probably ok to just replace the prop.
>> Otherwise a teardown is warranted.
>>
>> Ernie
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=124349#124349
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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