Voltage, EDM-700, trim switch follow-up

When I started Atlas yesterday I watched the voltage on the JPI and
the EI volt meters. It was pegged right at 14, which my A&P says is
nominal. It drops to 13.4 or 13.5 in cruise, which he also says is
fine.

So, the JPI EDM-700 is now enroute back to JP Instruments in
California. The tech I spoke with said that display problems (missing
LED links) were rather common, and that their turn-around time was
just 3 or 4 days. $150 plus shipping.

The unit is almost five years old, so I guess I shouldn't be too
upset.

Our trim switch, which has been inop in the aft direction for months,
turned out to be a somewhat unusual problem. My A&P took the rocker
switch apart, and found that someone in the distant past had put a
little piece of copper sheet, barely thicker than tin foil, over the
screws that are supposed to actuate the switches, apparently in an
effort to help make more consistent contact.

It may have been part of the original switch assembly, although it's
hard to imagine such a kludge. Anyway, somehow that piece of copper
had shifted, and was no longer making contact with the aft trim
switch. (The trim rocker is actually two switches; one for down, one
for up.) He experimented with various fixes, and ultimately ended up
cutting a razor blade (the only thing we found that wasn't too thick)
to size and replacing the piece of copper. He also discovered that
the aft switch itself was slightly askew in its mounting.

The combination of realigning the switch, and installing the new
"contact piece" made everything work again.

Then, he fixed something that has aggravated me for five years. The
trim switch/push-to-talk mounting plate has had a sheared mounting
screw since Day One. The previous owner had "fixed" this by attaching
the plate with a piece of strong tape. I had done him one better, and
RTV'd the mounting plate to the yoke, which worked perfectly for years
-- until I had cut it off to examine the inop switch.

This was months ago. In the interim, I went back to the "tape" method
-- which didn't hold well or last long. Thus, for the past two
months, using the push-to-talk meant holding the unit with your thumb
whilst pushing the talk button. This often failed, of course,
resulting in the switch plate moving, and us stuttering on the radio.

Yesterday my A&P drilled out the broken screw head and tapped a new
screw. Voila! For the first time since we bought Atlas in 2002, the
yoke is as designed, and everything works as intended.

Best of all, I didn't have to buy a stupid Piper trim switch, to the
tune of over $600.

Today, we're installing the JPI outside air temperature probe that I
purchased last May. We're gonna install it like Jack Allison did,
out in the left under-wing inspection panel -- an elegant install
compared to the usual "drill a big hole through the side of the plane"
method that most people use. It means removing the pilot-side
interior panels -- a giant pain -- but in the end it'll be a lot
nicer.

Of course, until we get the EDM-700 back, the probe won't be
registering much. g

Once that's installed, I'm planning to remove the ugly through-the-
windshield temperature probe. I've heard that you can simply put a
piece of masking tape over the hole (on the inside) and fill the hole
with clear RTV (removing the tape after its dry, naturally!) -- but
has anyone here actually done that?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:

Today, we're installing the JPI outside air temperature probe that I
purchased last May. We're gonna install it like Jack Allison did,

Once that's installed, I'm planning to remove the ugly through-the-
windshield temperature probe.

I could be wrong, but I don't think the JPI OAT probe is STCed as a
replacement for the factory-though-the-windshield probe.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Boise, ID

Jay Honeck wrote:
snip


Once that's installed, I'm planning to remove the ugly through-the-
windshield temperature probe. I've heard that you can simply put a
piece of masking tape over the hole (on the inside) and fill the hole
with clear RTV (removing the tape after its dry, naturally!) -- but
has anyone here actually done that?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"


Jay, the only thing I would say, is to put something like wax paper or
mylar on the inside and tape it in place. The adhesive on the duct tape
may inhibit the cure of the RTV. You may even find a clear acrylic
compound that you can put in there. Also, if you place the mylar on the
outside after you are complete you may get it to feather quite nicely to
the original material.
--

Regards, Ross
C-172F 180HP
KSWI

Frank Stutzman wrote:

Jay Honeck wrote:

Today, we're installing the JPI outside air temperature probe that I
purchased last May. We're gonna install it like Jack Allison did,


Once that's installed, I'm planning to remove the ugly through-the-
windshield temperature probe.


I could be wrong, but I don't think the JPI OAT probe is STCed as a
replacement for the factory-though-the-windshield probe.





That would be hillarious. A ****ty company to start with and then the
probe isn't a legal replacement. Reason #4650 to go with EI.

Newps wrote:
Frank Stutzman wrote:

I could be wrong, but I don't think the JPI OAT probe is STCed as a
replacement for the factory-though-the-windshield probe.


That would be hillarious. A ****ty company to start with and then the
probe isn't a legal replacement. Reason #4650 to go with EI.

I've never read the EI STC so I could be wrong, but I wouldn't be surprised
if the same situation exists with EI.

There are a lot more hoops to jump through in order to STC something as a
replacement (as opposed to being supplimental) for something specified in
the aircrafts type certificate. For something as trivial as an OAT probe,
I could understand a manufacturer not bothering.


--
Frank Stutzman
Bonanza N494B "Hula Girl"
Boise, ID

Frank Stutzman wrote:

Newps wrote:

Frank Stutzman wrote:


I could be wrong, but I don't think the JPI OAT probe is STCed as a
replacement for the factory-though-the-windshield probe.


That would be hillarious. A ****ty company to start with and then the
probe isn't a legal replacement. Reason #4650 to go with EI.


I've never read the EI STC so I could be wrong, but I wouldn't be surprised
if the same situation exists with EI.

There are a lot more hoops to jump through in order to STC something as a
replacement (as opposed to being supplimental) for something specified in
the aircrafts type certificate. For something as trivial as an OAT probe,
I could understand a manufacturer not bothering.


I had the EI US8A engine monitor in my 182 and used one of the unused
channels as the OAT, got rid of the juice can OAT. Check the TCDS,
there may be no requirements for an OAT to begin with.

Newps wrote:

I had the EI US8A engine monitor in my 182 and used one of the unused
channels as the OAT, got rid of the juice can OAT. Check the TCDS,
there may be no requirements for an OAT to begin with.

Certainly true. As one aviation sage (that I think we both know) is fond
of saying: "It depends!"

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Boise, ID

Jay, the only thing I would say, is to put something like wax paper or
mylar on the inside and tape it in place. The adhesive on the duct tape
may inhibit the cure of the RTV. You may even find a clear acrylic
compound that you can put in there. Also, if you place the mylar on the
outside after you are complete you may get it to feather quite nicely to
the original material.

Actually, I think my A&P said he was going to use a clear epoxy of
some sort, as RTV will "weather" over time and eventually fail.

I'll post how it comes out...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In article ,
Frank Stutzman wrote:

Jay Honeck wrote:

Today, we're installing the JPI outside air temperature probe that I
purchased last May. We're gonna install it like Jack Allison did,

Once that's installed, I'm planning to remove the ugly through-the-
windshield temperature probe.

I could be wrong, but I don't think the JPI OAT probe is STCed as a
replacement for the factory-though-the-windshield probe.

I went the field approval route when I replaced mine. The digital OAT probe
I used is PMA'd for a Bonanza but not Piper.

--
Bob Noel
(goodness, please trim replies!!!)

Jay Honeck wrote:
Today, we're installing the JPI outside air temperature probe that I
purchased last May. We're gonna install it like Jack Allison did,
out in the left under-wing inspection panel -- an elegant install
compared to the usual "drill a big hole through the side of the plane"
method that most people use. It means removing the pilot-side
interior panels -- a giant pain -- but in the end it'll be a lot
nicer.

I wish I could take credit...but can't as the shop at our home field did
the install. I sure like it though. I'd much rather have a hole
drilled through an inspection panel under the wing than through the side
of the fuselage.