Today's Message Index:
----------------------
1. 11:25 AM - Direction Indicator Needs (Owen Baker)
2. 03:14 PM - Direction Indicator Needs (Owen Baker)
3. 04:09 PM - Re: Direction Indicator Needs (Jeff Luckey)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Direction Indicator Needs |
6/10/2014
Hello Aeroelectric and Avionics Listers, I know that there are many
technically smart people on these lists and I would like to enlist your
assistance.
Picture this situation: There are hundreds (maybe thousands) of EAB
(Experimental Amateur Built) IFR capable aircraft flying around with
vacuum driven mechanical spinning mass gyroscopic attitude and
directional indicators. A large percentage of these builders and pilots
would like to (or need to) replace those indicators with something
electronic (other than expensive electrical motor driven mechanical
spinning mass gyroscopic) in nature and remove the entire vacuum system
from their EAB.
Replacing the attitude indicator does not appear to be a big problem in
meeting the requirement of 14 CFR 91.205 (d) (8) =9CGyroscopic
pitch and bank indicator (artificial horizon)=9D since there are
several offerings available. Here are some:
http://www.dynonavionics.com/docs/D6_intro.html
http://trutrakap.com/product/gemini-pfd/
http://www.grtavionics.com/mini.html
http://www.sandia.aero/?q=node/80
But there does not appear to be available an electronic directional
indicator that would meet the 14 CFR 91.205 (d) (9) criteria for a
=9CGyroscopic directional indicator (directional gyro or
equivalent)=9D if one believes that the Regulatory intended
direction to be indicated must indeed be the current aircraft magnetic
heading and not the current aircraft magnetic course (provided by GPS)
over the surface.
I feel that somewhere in the electronic magic that MEMS
<< https://www.memsnet.org/mems/what_is.html >>
and AHARS
<<
http://www.microstrain.com/inertial/3DM-GX3-25?gclid=CjgKEAjw2dqcBRC2q-
LXjpfxjnQSJAAeYF5LUC4gvWycBVg6DDW_mzzSdTyyF3q0yoQHrT6ij9VbvvD_BwE >>
represents there must be a practical, relatively inexpensive means of
creating a direction indicator that will meet the intended requirements
of 14 CFR 91.205 (d) (9). If so, I (and probably many others) would
like to buy one for my EAB airplane.
How about it experts (and entrepreneurs) are my desires hopeless and
unrealistic?
OC
'O C' Baker says "The best investment you can make is the effort to
gather and understand information."
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Direction Indicator Needs |
6/10/2014
Hello Dj Merrill, Thanks for your quick response. You wrote: ".... an
external magnetometer box which gives magnetic heading
information to the EFIS."
1) See here for information on what constitutes a magnetometer:
http://science.howstuffworks.com/magnetometer-info.htm
If the heading that appears on the display, see here:
http://www.grtavionics.com/mini.html#Features
is simply the indication of a remotely located magnetometer (which is
available for the Mini-X and Mini-AP, but not the Mini-B) then I don't think
that will meet the intended requirement of 14 CFR 91.205 (d) (9) criteria
for a Gyroscopic directional indicator (directional gyro or equivalent).
2) One other big downside of the Mini displays from GRT was GRT's failure to
package the units such that they could be readily installed in a standard
round nominally 3 inch instrument cut out hole where the old attitude
indicator resides. See here:
http://www.grtavionics.com/Mini%20Drawing%202.pdf
Needing to cut panel metal to install a Mini unit from GRT in an existing
panel raises the difficulty of a swap over significantly. Note that Sandia
recognized the significance of this issue and packaged the SAI 340 - Quattro
accordingly. See here:
http://www.sandia.aero/?q=system/files/SAI340BroR2Web.pdf
I am still searching.
OC
===================================================================
From: Dj Merrill
Sent: Tuesday, June 10, 2014 3:34 PM
Subject: Re: AeroElectric-List: Direction Indicator Needs
I am not familiar with the other brands, but the GRT EFIS units come
with an external magnetometer box which gives magnetic heading
information to the EFIS.
Is that what you are asking about?
-Dj
--
Dj Merrill - N1JOV - VP EAA Chapter 87
Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/
Glastar Flyer N866RH - http://deej.net/glastar/
================================================
On 06/10/2014 02:24 PM, Owen Baker wrote:
> But there does not appear to be available an electronic directional
> indicator that would meet the 14 CFR 91.205 (d) (9) criteria for a
> Gyroscopic directional indicator (directional gyro or equivalent) if
> one believes that the Regulatory intended direction to be indicated must
> indeed be the current aircraft magnetic heading and not the current
> aircraft magnetic course (provided by GPS) over the surface.
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Direction Indicator Needs |
...is simply the indication of a remotely located magnetometer (which is
=0Aavailable for the Mini-X and Mini-AP, but not the Mini-B) then I don't t
hink =0Athat will meet the intended requirement of 14 CFR 91.205 (d) (9) cr
iteria =0Afor a =9CGyroscopic directional indicator (directional gyro
or equivalent)=9D....=0A=0AI bet the magnetometer-driven heading ind
icator does satisfy the requirement.=C2- =0A=0A=0AThe reason the gyroscop
ic heading indicator is used is to get rid the lead/lag and dip issues asso
ciated with a magnetic compass.=C2- The modern EFIS units & their magneto
meter-based displays do not have these issues.=0A=0AThat's probably the rea
son for the "..or equivalent.." language in the reg.=0A=0A-Jeff=0A=0A=0A=0A
On Tuesday, June 10, 2014 3:26 PM, Owen Baker <bakerocb@cox.net> wrote:=0A
et>=0A=0A6/10/2014=0A=0AHello Dj Merrill, Thanks for your quick response. Y
ou wrote: "....=C2- an =0Aexternal magnetometer box which gives magnetic
heading=0Ainformation to the EFIS."=0A=0A1) See here for information on wha
t constitutes a magnetometer:=0A=0Ahttp://science.howstuffworks.com/magneto
meter-info.htm=0A=0AIf the heading that appears on the display, see here:
=0A=0Ahttp://www.grtavionics.com/mini.html#Features=0A=0Ais simply the indi
cation of a remotely located magnetometer (which is =0Aavailable for the Mi
ni-X and Mini-AP, but not the Mini-B) then I don't think =0Athat will meet
the intended requirement of 14 CFR 91.205 (d) (9) criteria =0Afor a
=9CGyroscopic directional indicator (directional gyro or equivalent)
=9D.=0A=0A2) One other big downside of the Mini displays from GRT was GRT's
failure to =0Apackage the units such that they could be readily installed
in a standard =0Around nominally 3 inch instrument cut out hole where the o
ld attitude =0Aindicator resides. See here:=0A=0Ahttp://www.grtavionics.com
/Mini%20Drawing%202.pdf=0A=0ANeeding to cut panel metal to install a Mini u
nit from GRT in an existing =0Apanel raises the difficulty of a swap over s
ignificantly. Note that Sandia =0Arecognized the significance of this issue
and packaged the SAI 340 - Quattro =0Aaccordingly. See here:=0A=0Ahttp://w
ww.sandia.aero/?q=system/files/SAI340BroR2Web.pdf=0A=0AI am still searchi
ng.=0A=0AOC=0A=0A===================
=========================0A
=0AFrom: Dj Merrill=0ASent: Tuesday, June 10, 2014 3:34 PM=0ATo: aeroelectr
ic-list@matronics.com ; bakerocb@cox.net=0ASubject: Re: AeroElectric-List:
Direction Indicator Needs=0A=0AI am not familiar with the other brands, but
the GRT EFIS units come=0Awith an external magnetometer box which gives ma
gnetic heading=0Ainformation to the EFIS.=0A=0AIs that what you are asking
about?=0A=0A-Dj=0A=0A-- =0ADj Merrill - N1JOV - VP EAA Chapter 87=0ASportsm
an 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/=0AGlastar Flyer N8
66RH - http://deej.net/glastar/=0A=0A============
=============0A=0AOn 06/10/2014 02:24 PM, Owen Bake
r wrote:=0A> But there does not appear to be available an electronic direct
ional=0A> indicator that would meet the 14 CFR 91.205 (d) (9) criteria for
a=0A> =9CGyroscopic directional indicator (directional gyro or equiva
lent)=9D if=0A> one believes that the Regulatory intended direction t
o be indicated must=0A> indeed be the current aircraft magnetic heading and
not the current=0A> aircraft magnetic course (provided by GPS) over the su
- =C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- -Matt Dralle, L
========
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|