Mailing List lml@lancaironline.net Message #65353
From: Frederick Moreno <frederickmoreno@bigpond.com>
Subject: Re: Prop overspeed??? MVP 50 indications
Date: Sat, 27 Apr 2013 09:14:12 +0800
To: Lancair Mail (lml@lancaironline.net) <lml@lancaironline.net>
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Interesting MVP 50 indications. 
 
Occasionally in recent flights I get an alarm that oil pressure is high after start up, reads 100+ psi.  Do a run up and it clears even before oil temperature changes.  It comes and goes, and seems independent of RPM on the ground, so I put it down to instrument error instead of a stuck oil pressure relief valve. 
 
Possibly important note: My MVP 50 is on the essential buss along with my PFD, back up horizon and a few other things, which means the buss is hot when I turn on the master and do the start.  So the voltage sag at the start may cause the MVP 50 to lose its brains momentarily.   I have lots of voltage spike protections built into that buss, but not much one can do about voltage sags.
 
Fred
 
 
 
 
-------Original Message-------
 
Date: 27/04/2013 4:02:26 AM
Subject: Re: [LML] Re: Prop overspeed???
 
Angier,
 
Your prop did not over speed.  Note that while the pump was running the voltage was lower than during the time the pump was not running.  While 13.2 VDC is not that low, the MVP may be sensitive to that or to an unusual ground loop relative to the pump ground.  The same may be true for the fuel flow sensor.  Check it out.
 
I like the hydraulic pressure included in the data logging.
 
Scott
 
PS do not worry about 2710 rpm..  You may want to change the limit values slightly.  Then again, why did the mstr wrn go away or did you reset it.
 
In a message dated 4/26/2013 2:10:57 P.M. Central Daylight Time, N4ZQ@VERIZON.NET writes:
Today's 2hr flight was normal in all respects with the single exception that immediately after liftoff, the MVP-50 began screaming 'check RPM'. The RPM display was close to 4000 and fuel flow spiked.
Nevertheless engine sounds remained normal. Sure got my attention.
At 6:29:28 and just as the gear started to come up is when the RPM indication spiked for all of about
5 seconds. Haven't seen this before.

What would the common, everyday prop overspeed sound like?? not that I ever want to hear it....

Angier Ames
N4ZQ









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