---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Tue 06/10/14: 3 ---------------------------------------------------------- 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 _____________________________________ Time: 11:25:09 AM PST US From: "Owen Baker " Subject: Avionics-List: 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 _____________________________________ Time: 03:14:47 PM PST US From: "Owen Baker " Subject: Avionics-List: 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 _____________________________________ Time: 04:09:04 PM PST US From: Jeff Luckey Subject: Re: Avionics-List: 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 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 ------------------------------------------------------------------------------------- Post A New Message avionics-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Avionics-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/avionics-list Browse Digests http://www.matronics.com/digest/avionics-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.