Remote Magnetometer - OR - Not

[gmcjetpilot]

I just received my Grand Rapids technology EFIS, Horizon 10.1 touch. Really nice quality. I didn't order a remote magnetometer. There is an optional magnetometer in the manual. When I ordered it I said give me everything I'm going to need. Apparently you don't need a remote magnetometer. Has anybody had luck with using the internal magnetometer in the unit?

 

[BH1166]

I just received my Grand Rapids technology EFIS, Horizon 10.1 touch. Really nice quality. I didn't order a remote magnetometer. There is an optional magnetometer in the manual. When I ordered it I said give me everything I'm going to need. Apparently you don't need a remote magnetometer. Has anybody had luck with using the internal magnetometer in the unit?

I did as you. I relied on gps for directional info. Some draw backs with no magnetometer is, you can’t use the wind direction, vector, speed data. Also, until you start moving, there is no data as to direction the nose is pointing. I also saw that on occasion getting an alignment at start up struggled to settle in until I started moving/taxiing. It works without magnetometer. I just recently installed one. It is an addon, and my older analog grt magnetometer will not work with new 10.1 EFIS SPORT or Horizon. So if you want magnetic data, get one. If tracking data is good for you, you don’t need one. I tried none, like it better with magnetometer/ magnetic data. There is no internal magnetometer.

 

[D Weisgerber]

I did the same as Butch, I like it better with the magnatometer. Without it I was getting heading direction from the GPS, of course that is only accurate when you're moving.

 

[Ironflight]

I did the same as Butch, I like it better with the magnatometer. Without it I was getting heading direction from the GPS, of course that is only accurate when you're moving.

Jst to be clear - you don’t get heading from GPS data, you get Track - they differ by the wind component.

 

[gmcjetpilot]

Thanks Gents: So no magnetometer at all internal to the EFIS unit itself? Hummmm. So it will work but not great. Without the magnetometer you have to have a magnetic compass as required equip.

The manual gets into a lot of detail about where to place the remote magnetometer specifically for RV's. Surprised they did not recommend it to me.

I am going to order it. GRT says DIGITAL Magnetometer now per above comment. It does not jump out on the website, not shown as an option list on Horiz 10.1 order page. I find that weird. It may not be mandatory, it now seems based on comments here (thank you) essential for good operation.

Cost $300 for GRT Magnetometer. May be they will give the airshow discount.

 

[Mel]

Thanks Gents: So no magnetometer at all internal to the EFIS unit itself? Hummmm. So it will work but not great. Without the magnetometer you have to have a magnetic compass as required equip.
The manual gets into a lot of detail about where to place the remote magnetometer specifically for RV's. Surprised they did not recommend it to me.
I am going to order it. GRT says DIGITAL Magnetometer now per above comment. It does not jump out on the website, not shown as an option list on Horiz 10.1 order page. I find that weird. It may not be mandatory, it now seems based on comments here (thank you) essential for good operation.
Cost $300 for GRT Magnetometer. May be they will give the airshow discount.

Some kind of "magnetic direction indicator" is required (for anything but daytime VFR). If you don't have the magnetometer, you will need some type of compass.

GRT's magnetometer is very nice and installation is easy. Their "older" magnetometer was pretty critical on orientation. Th new one is +/- 60° up or down.

The major problem with putting a magnetometer in the EFIS is there too much interference around the instrument panel location. It would be very difficult, if even possible, to "correct" for deviation.

 

[gmcjetpilot]

Some kind of "magnetic direction indicator" is required (for anything but daytime VFR). If you don't have the magnetometer, you will need some type of compass.

GRT's magnetometer is very nice and installation is easy. Their "older" magnetometer was pretty critical on orientation. Th new one is +/- 60° up or down.

The major problem with putting a magnetometer in the EFIS is there too much interference around the instrument panel location. It would be very difficult, if even possible, to "correct" for deviation.

CFR 91.205. That is not correct. Ever see a Piper Cub J3 instrument panel. That is day VFR. Compass was #1 Nav instruments (and your eyeballs, map, watch) from the most early days of flying before GPS was even glimmer in anyone's eyes. Even A-N "Radio Range", ADF, VOR, LOC don't work unless you know our heading.

(b) Visual-flight rules (day). For VFR flight during the day, the following instruments and equipment are required:

(1) Airspeed indicator.
(2) Altimeter.
(3) Magnetic direction indicator.
(4) Tachometer for each engine.
(5) Oil pressure gauge for each engine using pressure system.
(6) Temperature gauge for each liquid-cooled engine.
(7) Oil temperature gauge for each air-cooled engine.
(8) Manifold pressure gauge for each altitude engine.

Another 9 items not related to instrument panel for day VFR. For night VFR there are another 6 items.

You are right interference right behind the engine, electrical wiring, steel roil bar (slider). It is interesting you say the allowances for magnetometer is less critical or stringent for the digital unit. The manual must not be updated because it shows some strict orientation requirements.

Speaking of back up I have the GRT EIS separate display for engine. For airspeed, altitude mag direction in the past, early days of EFIS certified or EAB planes used mechanical, pitot/static instruments, and wet compass as back up for bare min flight instruments (day VFR). Since I only have one display I plan on a back up small EFIS. There are many non-NAV EFIS that will do the trick to get you home legally and safely. Even the jetliners have canned any mechanical gauges. The Standby instruments are glass. They run on essential DC buss, and also give standby attitude and NAV. However the primary EFIS is redundant to beat the band, and can reconfigure to restore information on both Captains and F/O's side. I don't need that for the RV-7. But if I put in a IFR GPS source I will for sure get more redundancy.

As far as accepting of EFIS magnetometer as meeting the FAR requirement, that was controversial in the past. Many designees and FAA folks balked at the idea of not having a wet compass. I believe that has been resolved and a wet compass is not needed. However I am 100% sure you will find some out there that want to see that jelly jar (or vertical mag compass) no batteries required installed, despite your dual AHAR, dual magnetometer, AHRS, GPS.... ADS-B weather or XM weather. Ha ha. They want that jelly jar compass.

Great Grandfather of Day VFR.. A simpler time. Before my day but I still make students fly by dead reckoning and pilotage, in part it's fun, and FAA still requires it.

 

[mburch]

CFR 91.205. That is not correct.

14 CFR 91.205 applies to aircraft with standard airworthiness certificates only.

Do the operating limitations for your RV with a special airworthiness certificate require any instruments for day VFR flight?

 

[gmcjetpilot]

14 CFR 91.205 applies to aircraft with standard airworthiness certificates only.

Do the operating limitations for your RV with a special airworthiness certificate require any instruments for day VFR flight?

Show me where it says that. Not to quarrel void of facts and regs.

So if you don't need magnetic compass during VFR day, what else does an "experimental" (which has to have an airworthiness certificate, albeit EAB). Do you need airspeed? Altitude?

PART 91 applies to everyone That means You, me, Commercial airplanes (Air transport Part 25), and GA planes (Standard and Normal Part 23) airplanes.

Certificated airplanes, "N" numbered, flying in national airspace needs a means to display magnetic heading, not just GPS track.

 

[Mel]

Show me where it says that. Not to quarrel void of facts and regs.
So if you don't need magnetic compass during VFR day, what else does an "experimental" (which has to have an airworthiness certificate, albeit EAB). Do you need airspeed? Altitude?
PART 91 applies to everyone That means You, me, Commercial airplanes (Air transport Part 25), and GA planes (Standard and Normal Part 23) airplanes.
Certificated airplanes, "N" numbered, flying in national airspace needs a means to display magnetic heading, not just GPS track.

How about the first sentence; §91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

Your operating limitations also contain a paragraph stating that 91.205 applies for night and/or IFR operations.

and for your other question; NO. Airspeed and Altitude instruments are not requires for daytime VFR. "Prudent" is one thing, 'legal" is quite another.

 

[gmcjetpilot]

How about the first sentence; §91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

Your operating limitations also contain a paragraph stating that 91.205 applies for night and/or IFR operations.

and for your other question; NO. Airspeed and Altitude instruments are not requires for daytime VFR. "Prudent" is one thing, 'legal" is quite another.

14 CFR 91.205 applies to aircraft with standard airworthiness certificates only.

Do the operating limitations for your RV with a special airworthiness certificate require any instruments for day VFR flight?

14 CFR 91.205 title: " Powered ivil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements." Well two things: 1) Depends on your operating limitations, but I concede you don't need a compass or any other instrument, be it flight (altimeter, airspeed) or engine (oil pressure or temp) for day VFR. See where I am going. There is a convoluted intersection of Part 91 and Part 23 planes and Part 61 which causes issues, and indirectly or directly applies to EAB aircraft. This is lawyer land, which I am not.

Not to quarrel let's do a thought experiment. To fly any Standard or EAB "N" number aircraft in national airspace (not Part 103) you need a pilots license, LSA, Recreational or Private at minimum under Part 61. How can you perform Part 61 standards, and follow Part 91 airspace rules of operation, including holding a magnetic heading and altitude without instruments? Navigate, dead reckoning? You can not perform to the standards of Part 61 or 91 with out some basic flight and navigation instruments. The most basic NAV instrument? Yep Mr. Jelly Jar Compass. ATC: "Turn to heading One Niner Zero". Pilot: "Ahaaaa Skyscooter 321 unable, negative magnetic heading indicator." ATC: "Did your compass fail Sir." Pilot: "Ahaaaa no. Never installed one, but can do track with my zippy GPS." Magnetic heading is still a thing.

How about not having engine instruments? By this line of argument or logic none of Part 91.205 applies (unless it was written into your operating limitations). What is legal and what is prudent are two different things. It is also not logical. What is not explicate in civil codes, regulations and laws, is filled in by we hope "Common Senses". However it is the Gov / Lawyers who do the filling in the blanks. These two groups and common sense sometimes can be mutually exclusive, no offense to Lawyers or Bureaucrats. The Gov/Legal system has the power and authority to settle arguments, even if they are wrong.

I am sure the FAA has much more clever ways to violate an EAB aircraft builder or operator without one or more Part 91.205 day VFR instruments and other equipment requirements than I can dream up. Don't need a seatbelt? No one is fighting to be exempt from that Part 91.205 day VFR requirement of seatbelts (and later shoulder belt), because well that would be dumb. One catch all is safe operations of an aircraft which will get you every time. I concede no instruments, none, zero, are required for day VFR. Try and get a DAR or FAA to give you the blessing.

PS FAR's are in Gov Civil Federal Register code (CFR) written by lawyers and interpreted by lawyers (aka Judges). I don't know of legal precedence. Since the late 1980's with advent of cheap portable powerful GPS navigation the lowly magnetic heading seems to have become the red headed step child of aviation in general, and specifically a NAV relic of the past, throw it out the window. I still love that little rascal. You cannot get much more simple and dependable than a compass. Yes my plane has mag compass, airspeed, altimeter and full 5 point harness not required to fly Day VFR, but it makes me feel warm and fuzzy. Ha ha.

 

[PhatRV]

I am going to sidestep the ongoing legal arguments in these posts.

I have a separate magnetometer for my Dynon system. The ADHARS is mounded next to the baggage compartment and it means if I put my tool box or anything ferrous there, it will interfere with the magnetic readings. To remedy this, I purchased a separate standalone magnetometer and it is mounted at the wingtip, well away from the magnetic interferences in the fuselage.

Had I build my panel again, I would purchase the new Dynon avionic mounting kit which mounts most of the Dynon avionic boxes at the panel. There is fewer magnetic disturbance here and I won't have to purchase a separate magnetometer .

 

[gmcjetpilot]

How about the first sentence; §91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

Your operating limitations also contain a paragraph stating that 91.205 applies for night and/or IFR operations.

and for your other question; NO. Airspeed and Altitude instruments are not requires for daytime VFR. "Prudent" is one thing, 'legal" is quite another.

I said that. I know. Did you read and understand the rest of what I wrote. Pls read it. I'm not going to repeat myself.

 

[gmcjetpilot]

I am going to sidestep the ongoing legal arguments in these posts.

I have a separate magnetometer for my Dynon system. The ADHARS is mounded next to the baggage compartment and it means if I put my tool box or anything ferrous there, it will interfere with the magnetic readings. To remedy this, I purchased a separate standalone magnetometer and it is mounted at the wingtip, well away from the magnetic interferences in the fuselage.

Had I build my panel again, I would purchase the new Dynon avionic mounting kit which mounts most of the Dynon avionic boxes at the panel. There is fewer magnetic disturbance here and I won't have to purchase a separate magnetometer .

Don't side step legality too much. Flying and FAA aggressive enforcement regulations is a thing. Dynon is different, GRT puts the AHARS in the same box as screen and just the magnetometer is separate.

The decision axiomatic hearing from fellow GRT users. Not an expensive opton. I will install the remote magnetometer. The base unit does not have an internal magnetometer, none. Reading the manual the EFIS will work work fine without the optional magnetometer, but with no wind vector (with GPS), and of course no magnetic heading.

Some EFIS like the old Dynon D10 had both internal and optional external magnetometer. I think as stated before magnetometer can't go in or behind inrltrument panel. Why GRT thinks it's optional not sure

This thread took a hard drift from does an electronic compass (magnetometer) suffice for a wet compass. I'm saying yes. Cut print.

However we got into NO magnetic heading is needed because 91.205 says standard category?. Good luck with that. Read what I wrote above. Up to you. But not having ANY magnetic heading data be it electronically or mechanically sensed is not allowed, even in experimental airplanes. GPS track is not enough. If you ever flew in 30 to 230 kt winds (jet stream) knowing your actual Mag heading vs track is a must. Accepting ATC headings is magnetic. Do as you like. Waste of time to beat that dead horse.

Thank you all who gave me the info I needed. I don't think this is worth of debate flying with no magnetic heading. I am closing thread, and buying the magnetometer to get the full capabilities from my GRT Glass.