Today's Message Index:
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1. 06:26 AM - Encoding Altimeter ()
2. 03:06 PM - Re: Encoding Altimeter (Charles Reiche)
3. 06:54 PM - Re: Encoding Altimeter (William Gill)
Message 1
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Subject: | Encoding Altimeter |
4/22/2008
Hello Bill, Thanks for your input. You wrote:
1) "OR...you could buy a Dynon ........."
Since the Dynon units do not contain a TSO'd altitude encoder operating the
Dynon unit alone to feed a transponder in flight would presently leave one
in violation of FAR Sec 91.217 (as interpreted by FAA HQ). There are two
ways to approach this condition:
A) Purchase and install a separate TSO'd altitude encoder and use that
encoder to feed the aircraft's transponder.
B) Decide that violation of 91.217 is an acceptable risk and feed the
transponder from the non TSO'd altitude encoder contained in the Dynon unit.
2) ".....and save even more during the IFR recertification check."
My local avionics shop charges a flat fee for the FAR Sections 91.411 and
91.413 required testing. This fee has been the same no matter whether I do
the labor of removing and reinstalling the altimeter and TSO'd altitude
encoder, for bench testing and any adjustments needed prior to the airplane
side testing, or they do that labor. (By the way, four years ago that flat
fee was $150, now it is $300.)
3) "........the avionics shops actually prefer the Dynon due to their
accuracy and simplicity."
I hope that the avionics shops continue this practice without any regard for
what FAR Sec 91.217 says.
4) ".......the avionics shops actually prefer the Dynon due to their
accuracy and simplicity."
I wonder about the complexity of removing and reinstalling an EFIS from the
airplane compared to the complexity of removing and reinstalling an
altimeter and separate TSO'd altitude encoder should any bench testing and
adjusting be needed.
A) Maybe EFIS removal and reinstallation is no big deal, but I envision a
bunch of connections, particularly if it is the type of EFIS that also
includes displaying engine performance parameters.
B) Maybe the EFIS's have no means of local avionics shop adjustment.
C) Maybe the EFIS's would never need adjustment.
D) What has been the experience of EFIS operators that have actually been
through FAR 91.411 and 91.413 checks, as appropriate, after flying for at
least two years?
Would any EFIS owners and operators care to comment on these points?.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
---------------------------------------------------
Time: 09:05:34 PM PST US
From: "William Gill" <wgill10@comcast.net>
Subject: RE: Avionics-List: Encoding Altimeter
OR...you could buy a Dynon and save even more during the IFR
recertification check. In fact, the avionics shops actually prefer the
Dynon due to their accuracy and simplicity.
Bill
Message 2
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Subject: | Re: Encoding Altimeter |
I have no experience with the dynon other than I want my friend to put one
in his rv7. But I can tell you that in installations such as this and like
the G1000, its easier to certify devices in the airplane rather than
removing them so you can be using whatever its readout is to certify it. I
have run across one GDC 74A (Garmin g1000 air data computer) that failed a
test point just slightly out of spec but garmin allows us to recalibrate and
electrically slide the scale so everything is within spec all the way up.
Remember that down low the tolerance is +/- 20 feet for altimeter
certification and up over 20k its well over +/- 100 feet. Mechanical
altimeters can and do sway their actual reading all over the place up at
altitude, and generally the air data computer tpye devices are pretty darn
close.
YMMV
Charlie
----- Original Message -----
From: <bakerocb@cox.net>
<wgill10@comcast.net>
Sent: Tuesday, April 22, 2008 9:23 AM
Subject: Avionics-List: Encoding Altimeter
>
> 4/22/2008
>
> Hello Bill, Thanks for your input. You wrote:
>
> 1) "OR...you could buy a Dynon ........."
>
> Since the Dynon units do not contain a TSO'd altitude encoder operating
> the Dynon unit alone to feed a transponder in flight would presently leave
> one in violation of FAR Sec 91.217 (as interpreted by FAA HQ). There are
> two ways to approach this condition:
>
> A) Purchase and install a separate TSO'd altitude encoder and use that
> encoder to feed the aircraft's transponder.
>
> B) Decide that violation of 91.217 is an acceptable risk and feed the
> transponder from the non TSO'd altitude encoder contained in the Dynon
> unit.
>
> 2) ".....and save even more during the IFR recertification check."
>
> My local avionics shop charges a flat fee for the FAR Sections 91.411 and
> 91.413 required testing. This fee has been the same no matter whether I do
> the labor of removing and reinstalling the altimeter and TSO'd altitude
> encoder, for bench testing and any adjustments needed prior to the
> airplane side testing, or they do that labor. (By the way, four years ago
> that flat fee was $150, now it is $300.)
>
> 3) "........the avionics shops actually prefer the Dynon due to their
> accuracy and simplicity."
>
> I hope that the avionics shops continue this practice without any regard
> for what FAR Sec 91.217 says.
>
> 4) ".......the avionics shops actually prefer the Dynon due to their
> accuracy and simplicity."
>
> I wonder about the complexity of removing and reinstalling an EFIS from
> the airplane compared to the complexity of removing and reinstalling an
> altimeter and separate TSO'd altitude encoder should any bench testing and
> adjusting be needed.
>
> A) Maybe EFIS removal and reinstallation is no big deal, but I envision a
> bunch of connections, particularly if it is the type of EFIS that also
> includes displaying engine performance parameters.
>
> B) Maybe the EFIS's have no means of local avionics shop adjustment.
>
> C) Maybe the EFIS's would never need adjustment.
>
> D) What has been the experience of EFIS operators that have actually been
> through FAR 91.411 and 91.413 checks, as appropriate, after flying for at
> least two years?
>
> Would any EFIS owners and operators care to comment on these points?.
>
> 'OC' Says: "The best investment we can make is the effort to gather and
> understand knowledge."
>
> ---------------------------------------------------
>
> Time: 09:05:34 PM PST US
> From: "William Gill" <wgill10@comcast.net>
> Subject: RE: Avionics-List: Encoding Altimeter
>
>
> OR...you could buy a Dynon and save even more during the IFR
> recertification check. In fact, the avionics shops actually prefer the
> Dynon due to their accuracy and simplicity.
>
> Bill
>
>
>
Message 3
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Subject: | Encoding Altimeter |
I have the Dynon and a mechanical altimeter...both remained in the plane
for testing and both altimeters met the requirements. However, the
transponder was removed for bench testing.
Bill
-----Original Message-----
From: owner-avionics-list-server@matronics.com
[mailto:owner-avionics-list-server@matronics.com] On Behalf Of Charles
Reiche
Sent: Tuesday, April 22, 2008 5:02 PM
Subject: Re: Avionics-List: Encoding Altimeter
<reichec@verizon.net>
I have no experience with the dynon other than I want my friend to put
one
in his rv7. But I can tell you that in installations such as this and
like
the G1000, its easier to certify devices in the airplane rather than
removing them so you can be using whatever its readout is to certify it.
I
have run across one GDC 74A (Garmin g1000 air data computer) that failed
a
test point just slightly out of spec but garmin allows us to recalibrate
and
electrically slide the scale so everything is within spec all the way
up.
Remember that down low the tolerance is +/- 20 feet for altimeter
certification and up over 20k its well over +/- 100 feet. Mechanical
altimeters can and do sway their actual reading all over the place up at
altitude, and generally the air data computer tpye devices are pretty
darn
close.
YMMV
Charlie
----- Original Message -----
From: <bakerocb@cox.net>
<wgill10@comcast.net>
Sent: Tuesday, April 22, 2008 9:23 AM
Subject: Avionics-List: Encoding Altimeter
>
> 4/22/2008
>
> Hello Bill, Thanks for your input. You wrote:
>
> 1) "OR...you could buy a Dynon ........."
>
> Since the Dynon units do not contain a TSO'd altitude encoder
operating
> the Dynon unit alone to feed a transponder in flight would presently
leave
> one in violation of FAR Sec 91.217 (as interpreted by FAA HQ). There
are
> two ways to approach this condition:
>
> A) Purchase and install a separate TSO'd altitude encoder and use that
> encoder to feed the aircraft's transponder.
>
> B) Decide that violation of 91.217 is an acceptable risk and feed the
> transponder from the non TSO'd altitude encoder contained in the Dynon
> unit.
>
> 2) ".....and save even more during the IFR recertification check."
>
> My local avionics shop charges a flat fee for the FAR Sections 91.411
and
> 91.413 required testing. This fee has been the same no matter whether
I do
> the labor of removing and reinstalling the altimeter and TSO'd
altitude
> encoder, for bench testing and any adjustments needed prior to the
> airplane side testing, or they do that labor. (By the way, four years
ago
> that flat fee was $150, now it is $300.)
>
> 3) "........the avionics shops actually prefer the Dynon due to their
> accuracy and simplicity."
>
> I hope that the avionics shops continue this practice without any
regard
> for what FAR Sec 91.217 says.
>
> 4) ".......the avionics shops actually prefer the Dynon due to their
> accuracy and simplicity."
>
> I wonder about the complexity of removing and reinstalling an EFIS
from
> the airplane compared to the complexity of removing and reinstalling
an
> altimeter and separate TSO'd altitude encoder should any bench testing
and
> adjusting be needed.
>
> A) Maybe EFIS removal and reinstallation is no big deal, but I
envision a
> bunch of connections, particularly if it is the type of EFIS that also
> includes displaying engine performance parameters.
>
> B) Maybe the EFIS's have no means of local avionics shop adjustment.
>
> C) Maybe the EFIS's would never need adjustment.
>
> D) What has been the experience of EFIS operators that have actually
been
> through FAR 91.411 and 91.413 checks, as appropriate, after flying for
at
> least two years?
>
> Would any EFIS owners and operators care to comment on these points?.
>
> 'OC' Says: "The best investment we can make is the effort to gather
and
> understand knowledge."
>
> ---------------------------------------------------
>
> Time: 09:05:34 PM PST US
> From: "William Gill" <wgill10@comcast.net>
> Subject: RE: Avionics-List: Encoding Altimeter
>
>
> OR...you could buy a Dynon and save even more during the IFR
> recertification check. In fact, the avionics shops actually prefer the
> Dynon due to their accuracy and simplicity.
>
> Bill
>
>
>
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