Sender: <marv@lancaironline.net>
To:  lml@lancaironline.net
Date: Fri, 18 Jan 2013 15:04:16 -0500
Message-ID: <redirect-6018917@logan.com>
Received-SPF: pass
 receiver=logan.com; client-ip=209.85.223.173; envelope-from=bbreen@cableone.net
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: quoted-printable
Subject: RPM on IO550N
From: Berni Breen <bbreen@cableone.net>
Mime-Version: 1.0 (1.0)

I just started experiencing widely varying RPM read outs on all 3 of the gau=
ges of my Lancair Legacy.  During run up and subsequent take off my MFD, PFD=
 and EIS all show correct RPM read outs.  Not until I get into cruise and se=
t the prop to 2400 do I see the problem.  I slowly begin to see all 3 of the=
 read outs start to show a 2300 to 2600 (or there abouts) variance.  All 3 g=
auges are in sync and agreement on the numbers.  In other words, they all 3 r=
ead the same thing and the variance is very rapid up and down.  Since I have=
 already concluded that the prop governor is functioning properly and I do n=
ot feel or hear a prop pitch change during these occurrences, I am all but 1=
00% sure I have some sort of erroneous information being sent to my "glass" a=
nd therefore erroneous readings.  As such I believe I need to check all of t=
he wiring and or "pick ups" between the engine and my MFD, PFD and EIS.  My p=
roblem is that I am not familiar with any of that.  Can someone reading this=
 please help me get started by suggesting where I should look for the source=
 of where my equipment gets the RPM information from the IO550 (location of p=
ick up)?  Further, any kind of procedure to track down where or what my prob=
lem might be would be most appreciated.

BTW, my read outs are on my GRT HX MFD and PFD as well as my VP200.  I know t=
hese units are displaying what they believe to be accurate information as ev=
erything else is functioning flawlessly.  I removed my prop governor, sent i=
t for overhaul and it checked out perfect.

Sent from my iPad
Berni Breen
Bbreen@cableone.net=