Sender: <marv@lancaironline.net>
To:  lml@lancaironline.net
Date: Sat, 19 Jan 2013 18:27:23 -0500
Message-ID: <redirect-6020178@logan.com>
Received-SPF: pass
 receiver=logan.com; client-ip=216.32.181.186; envelope-from=henry@cptgroup.com
Received-SPF: pass (mail228-ch1: domain of cptgroup.com designates 157.56.240.213 as permitted sender) client-ip=157.56.240.213; envelope-from=henry@cptgroup.com; helo=BL2PRD0711HT003.namprd07.prod.outlook.com ;.outlook.com ;
From: Henry Arjad <henry@cptgroup.com>
Subject: RE: [LML] RPM on IO550N
Thread-Topic: [LML] RPM on IO550N
Thread-Index: AQHN9bcHbwT0+EJxPEqJsdswogWgSZhPr31A
Disposition-Notification-To: Henry Arjad <henry@cptgroup.com>
References: <list-6018915@logan.com>
In-Reply-To: <list-6018915@logan.com>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

Berni,

I had the same experience few months back with my Legacy.  For no reason at=
 all, I started seeing strange and erratic rpm readings on my Dynon system.=
  It was obvious that the engine was fine, i.e. no over speed or change in =
power experienced.  The problem gradually got worse as we conducted flight =
tests and tried to find the cause.  During one of my test flights, without =
any warning, the rpm stabilized and started functioning properly.  After la=
nding and visual inspection, I decided to go for another flight to see what=
 I would find out.  During the run-up, the magneto test failed.  The magnet=
o had less than 100 hours on it after the 500 hours inspection/repair.  The=
 magneto was removed and sent to the shop for further evaluation.  The repa=
ir shop called me and said that the magneto had check out ok with no proble=
ms.  I was adamant about the magneto having failed during run-up and asked =
him to heat the unit while testing.  I received a call from the shop shortl=
y that the magneto had indeed failed after having it heated up.  It was det=
ermined that the coil was the problem and it was replaced and the unit was =
installed in the airplane and has been working just fine ever since. =20

That was my experience with a similar problem.  I hope this helps.

=A0
Henry Arjad=20
N22YY  KSNA =20


-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Bern=
i Breen
Sent: Friday, January 18, 2013 12:04 PM
To: lml@lancaironline.net
Subject: [LML] RPM on IO550N

I just started experiencing widely varying RPM read outs on all 3 of the ga=
uges of my Lancair Legacy.  During run up and subsequent take off my MFD, P=
FD and EIS all show correct RPM read outs.  Not until I get into cruise and=
 set 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.  Al=
l 3 gauges are in sync and agreement on the numbers.  In other words, they =
all 3 read the same thing and the variance is very rapid up and down.  Sinc=
e I have already concluded that the prop governor is functioning properly a=
nd I do not feel or hear a prop pitch change during these occurrences, I am=
 all but 100% sure I have some sort of erroneous information being sent to =
my "glass" and therefore erroneous readings.  As such I believe I need to c=
heck all of the wiring and or "pick ups" between the engine and my MFD, PFD=
 and EIS.  My problem is that I am not familiar with any of that.  Can some=
one reading this please help me get started by suggesting where I should lo=
ok for the source of where my equipment gets the RPM information from the I=
O550 (location of pick up)?  Further, any kind of procedure to track down w=
here or what my problem 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=
 these units are displaying what they believe to be accurate information as=
 everything else is functioning flawlessly.  I removed my prop governor, se=
nt it for overhaul and it checked out perfect.

Sent from my iPad
Berni Breen
Bbreen@cableone.net
--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html