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  #11  
Old 09-24-2015, 02:02 PM
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Brantel Brantel is online now
 
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Originally Posted by dave4754 View Post
So True Dan, just a little surprised. I was concerned about the idea of adjustable pitch prop from the beginning and this was a little spooky.

Dave
Big difference between a ground adjustable prop vs a constant speed prop....
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  #12  
Old 09-24-2015, 02:03 PM
David-aviator David-aviator is offline
 
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Originally Posted by aeroaddict View Post
Excuse my possible ignorance here, but what happens now?
Does Hartzell review internal processes to capture possible bad product?

Does Hartzell notify customers that possible discrepancies occurred during the manufacturing of their propeller?

And what about the 'discrepant' chemical composition (I assume of the propeller base material)?
Good questions.
Also, no mention of the over speed record in "Mayday Flight Engine Data". Does that mean it is deemed not a factor?
My guess Hartzell will have an opinion about that.
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  #13  
Old 09-24-2015, 05:06 PM
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Alan Carroll Alan Carroll is offline
 
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Originally Posted by ChiefPilot View Post
The "Mayday Flight Engine Data" shows prolonged operation above RPM redline. The owner's manual for my BA Hartzell says that more than 3 minutes above 103% RPM "requires evaluation by an appropriately licensed propellor repair facility". 103% equates to 2781 RPM and there are numerous sample points beyond this value.
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I may be looking at different version of the manual, but the graph I found indicates no time limit operation at 103%. It shows a 3 minute limit for operation at 105%.

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  #14  
Old 09-24-2015, 05:14 PM
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Originally Posted by Alan Carroll View Post
I may be looking at different version of the manual, but the graph I found indicates no time limit operation at 103%. It shows a 3 minute limit for operation at 105%.

Same graph as in mine. It would suggest that, as I stated, operation above 103% will require an a visit with the appropriate facility. 103% or below would go longer. We're saying the same thing.
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  #15  
Old 09-24-2015, 05:59 PM
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Alan Carroll Alan Carroll is offline
 
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Originally Posted by ChiefPilot View Post
Same graph as in mine. It would suggest that, as I stated, operation above 103% will require an a visit with the appropriate facility. 103% or below would go longer. We're saying the same thing.
You're right; I misread your statement.
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  #16  
Old 10-04-2015, 11:10 AM
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skylor skylor is offline
 
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Default Propellor Model

Jason,

The NTSB information has a link to "Hartzell Propeller Information" which appears to show models with the 7497 blades. You had the 7466 blades, correct?

Skylor
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  #17  
Old 10-05-2015, 10:13 PM
jrovey jrovey is offline
 
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Originally Posted by skylor View Post
Jason,

The NTSB information has a link to "Hartzell Propeller Information" which appears to show models with the 7497 blades. You had the 7466 blades, correct?

Skylor
I had the F7496 blades.
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  #18  
Old 10-06-2015, 05:40 AM
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Originally Posted by David-aviator View Post
Also, no mention of the over speed record in "Mayday Flight Engine Data". Does that mean it is deemed not a factor?
My guess Hartzell will have an opinion about that.
Overspeed equates to increased centrifugal force. Here the blade lost a pin, which has nothing to do with centripetal force.
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Last edited by Mike S : 10-06-2015 at 08:14 AM.
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  #19  
Old 10-06-2015, 11:35 AM
RVDan RVDan is offline
 
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Originally Posted by DanH View Post
Overspeed equates to increased centrifugal force. Here the blade lost a pin, which has nothing to do with centripetal force.
One of the other forces acting on a propeller is the centrifical twisting force that increases with RPM. Doesn't sound like that is the problem though given the crack origin. It is interesting to note that shot peening is typically done to increase the resistance of a metal to fatigue cracking.

Hartzell will likely have some take on this also.
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  #20  
Old 10-14-2015, 11:17 AM
lesdoud lesdoud is offline
 
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Default We're looking into it.

The RV-8 accident NTSB Probable Cause Report involving a pitch change knob failure was brought to our attention two weeks after the report was released. Hartzell did not participate in the investigation so we are looking into the facts and circumstances that went into the report conclusions. Hartzell will examine the accident propeller soon and confer with the NTSB metallurgical lab about their conclusions. At the present time Hartzell has no concerns with shot peened pitch change knobs on approved engine/propeller combinations operating within the limitations defined for the applicable engine configuration. “Approved” engine/propeller combinations include type certified combinations or Experimental Amateur Built applications specifically approved by Hartzell correspondence. If you have questions regarding propeller operating limitations for your specific engine/propeller combination, please contact Hartzell Propeller Product Support. You will be asked for your engine configuration including compression ratio, ignition systems, modified camshafts, crankshaft, pistons, induction, turbo/superchargers, exhaust, injections systems such as alcohol or nitrous oxide, or any other modification that would alter the power and torsional vibration characteristics.

Les Doud
Air Safety Investigator - Hartzell Propeller
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