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Best EFIS system

Denok

Active Member
Patron
Well, what had to happen, happened. My Blue mountain lite G4 Efis went dead on me this week having suffered from a toasted CPU Board. I can have it fixed for approximatly 1000$ but is it really worth it? Will I have a few years of trouble free operation? From what I have seen so far with the unit, it's reliability is somewhat shaky so I've been wondering, would it be better to start thinking about a whole new panel with reliable avionics?
Many systems are out there and none are more tempting that Garmin's dual screen G3X system but as with any systems Garmin makes, it is also the most expensive so I'm asking all you avionics techno wizards: What would be the best Efis system (excluding G3X), having engine monitoring capabilities, synthetic vision, compatibility with a GNS 430W and can interface properly with an autopilot (to be bought since my BMA autopilot would also have to be removed..:mad::mad::mad::mad::mad:) would you choose? Dynon, GRT, Advanced, Trutrack? Any feedbacks on past experiance with any of these systems. What Autopilot would you add to it? Is Garmin the only way to go regardless of price:cool:considering I will fly IFR with my new avionics.
Thanks For your help.
Denis
RV-7
C-GUED
 
EFIS

Two summary articles in Kitplanes by Stein Bruch might be helpful. Have you read these? Sorry about your Blue Mountain and agree the best course might be a new panel. Best of luck to you.
 
Your questions is not something that is easy to answer.

Everyone has personal likes and dislikes that will filter into any recommendation.

Also, what may be recommended today may be obsolete tomorrow, at least that is what the state-of-the-art in EFIS seems to be doing.

I notice you did not include MGL in your list, you might take a look at them. The owner is a member here, and seems to be absolutely straight forward with his advice and info, he will even recommends other competitors products if they fit the bill better than his do. Hard to get more honest than that.

I have GRT, older units that came with the project, and I am having a real love/hate relationship with them.

The units have an incredible amount of versatility, and ability, but it is very frustrating to understand/learning how to use them.:confused:---but as I said they are older units, so hopefully the newer stuff is more user friendly.

On the other hand, the support at GRT is absolutely top notch.:D
 
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What would be the best Efis system (excluding G3X), having engine monitoring capabilities, synthetic vision, compatibility with a GNS 430W and can interface properly with an autopilot (to be bought since my BMA autopilot would also have to be removed..:mad::mad::mad::mad::mad:) would you choose? Dynon, GRT, Advanced, Trutrack? Any feedbacks on past experiance with any of these systems. What Autopilot would you add to it? Is Garmin the only way to go regardless of price:cool:considering I will fly IFR with my new avionics.

The answer is the one that meets all your mission requirements. :D

You'll get many biased opinions and everyone on VAF has one.

Since you mentioned IFR, I would go with a independent auto pilot, such as Trutrak. I would personally avoid integrated APs, but then that is a risk decision that you'll need to decide for yourself.

With all kidding aside, any of the vendors you mentioned will work, but there are differences between the vendors. Only you can determine what's important to you. What's important to me or anyone else doesn't count.
 
I have the GRT dual screen, dual AHAR and have been extremely happy with them, both in regards to functionality, reliability and customer services has been next to none. I believe much user friendlier then the standard six pack in IFR.
 
It does very much depend for what you use your airplane. For IFR I would stick with AFS or GRT - or Garmin if you have deep pockets - and I would steer clear of boxes that come with an on-board autopilot. My current favorite is Advanced Flight Systems - a huge amount of functionality all in one box with an autopilot provided by Trutrak if you require it.

Pete
 
I love my Advanced Flight Systems but it is a hard decision. The competition and quality of most of the units out there are really good. AFS, GRT, MGL, Dynon, and of course Garmin are all fine equipment, so take your time and make sure of what you need and what you want, and have fun doing it!
 
Yeah it would be terrible to purchase an EFIS that gives you the AP controller for free...terrible.

How many attitude backups does a person need to fly IMC?

Who in their right mind would fly an aircraft in IMC with one EFIS and one stand alone AP and no other backups?

Put together the right panel with an integrated AP can save you money and also be just as redundant. It is about the total package not the individual components!

Also, nothing says you have to use the integrated AP. There is not an EFIS out there that will not work side by side with a third party stand alone AP. The typical third party AP does not have to be controlled by an EFIS or even connected to one to work.....

Are there advantages to using an EFIS in between the NAV sources and the less expensive AP's to gain features that are not in the AP natively? Sure there are but if that EFIS dies, you just lost all those advantages and I hope you put in an EFIS/GPS switch so you can drive your stand alone AP directly from the NAV sources.

How long will a stand alone AP stay sunny side up if it loses its NAV source?

GRT, MGL and Dynon seem to think there is value in integrated AP's...are they wrong?
 
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Hi Denis,

I can see that you are fairly new to VAF (based on your post count), so you may not be aware that this question gets asked over and over again, and there are literally hundreds of threads in the archives that will help you to understand the choices available to. I moved your post from the "General" area to the "Glass Cockpit" forum. Sit yourself down with a tall beverage of your choice and lots of time - there is plenty to keep you reading for hours...make that days!

In the end, no one is going to make that choice for you - you'll have to collect all the data you can, then make an informed decision based on your actual needs. There are not that many people who have a lot of time behind more than one of the popular EFIS choices, so it is hard to get valid comparisons - you can add to your "filter" as you read.

I helped Stein Bruch with a forum at OSH this year on EFIS choices. We are most proud of the fact that we talked and answered questions for an hour and a half and never once recommended a particular brand! ;) One size does not fit all....

Paul (three airplanes, three different EFIS's - for different reasons and different jobs!)
 
I would personally avoid integrated APs

What kind of logic is that
scratchhead.gif


If your Tru Trak falls over....what ya gunna do then? Still down an AP!

Facts boys FACTS!!!

If you have an aircraft you want to use IFR have a back up attitude system, have a back up radio and a back up NAV. On that topic I think two VOR's is a waste, even in the USA where there are VORs everywhere. a G396/496 is a perfect backup that is the perfect tool to save your bacon even if not a TSO'd NAV.

So here is my panel
m_IMG_2208.jpg


So having the D100 as the master if it fails, one button and the D180 page flips to being the D100 again, so all I have to do is hand fly the plane for a change.....which you should keep your hand in at. Ohhh and the CDI is gone too! OK will have to use the one on the GNS530 :eek:

I must apologise for the sacrastic tone but I am forever seeing far too much **** about systems and failure modes that is not justified at all.

Think it through very carefully.

If I was to build another IFR panel it would be a dual Skyview system, but if space and $$ were an issue another D100/D180 system.

AFS looks lovely too........
 
Several comments here have centered around failure modes/integration of the autopilot.

I've always been concerned about too much integration into a so-called 'god-box', where a single point failure can make you deaf, dumb and blind.

An autopilot can make an excellent backup system if the EFIS fails, as long as it is independent. However, the new autopilots emerging from the EFIS vendors are all integrated. Add to that the trend for the EFIS to become a virtual front panel for Transponders, Comms, Electrical Load Controllers and so on and we are all well beyond simple failure scenarios.

At first look, one would think that a dual EFIS system would mitigate these problems, but there has always been a reversion problem: if the autopilot/transponder/comm/electrical is physically connected to only one EFIS, then the second EFIS can't take over these instruments in a primary failure.

Dynon seems to have thought a lot about this. The SkyView network allows multiple components to share a redundant physical bus so that there is a reasonable reversion scenario. The problem of having non-SkyView instruments that use RS232 serial ports connected to a single EFIS was fixed in a recent software revision. This change allows two EFIS system to 'wire-or' their serial ports together. In this case a failing EFIS will go off-line while the standby EFIS will automatically take over the control of the serial ports.

Of course, this requires using two EFIS systems from the same manufacturer, rather than an alternate technology device. It's also possible to implement this serial port cut-over with a multi-pole switch, but that's a bit of a wiring mess and may need a lot of in-flight mode reconfiguration.

I think we are finally reaching what I call "complex simplicity", where once a device becomes sufficiently complex, it becomes easy to use. The best example of this is the automotive automatic transmission. In aircraft, EFIS systems have a way to go still, but the high levels of integration and some really clever hardware and software design are starting to make these systems compelling.

Vern
 
BM doesn't count

Not fair to base assumptions using BM equipment. Realistically they had serious reliability problems due to heat and a less than stellar AHARS. The other thing is that technology has changed a lot in the last 3 yrs so comparing a system designed and built 5 yrs ago to what is offered today is apples and oranges. Curious that no one is considering the Aspen solution.
 
C'mon guys

Bob was NOT attacking any of your decisions or infering that somehow your own personal opinions were based on any lack of intelligence when he said;

"I would personally avoid integrated APs, but then that is a risk decision that you'll need to decide for yourself".

He was just giving HIS opinion.

Sometimes the attacks here make me want to stop reading this stuff.:(
 
Hi Denis,

As you can tell, on this subject passions run high and so do opinions. It's sometimes hard to sort out objectivity and obviously people are passionate about their choices. It's human nature for people to defend their position on the equipment they purchased as the best choice....but that's the best choice for them, not necessarily everyone else. Add to the mix that all of the products are so darned good that it truly is hard to make a decision and it's a very accurate statement to say that there really is no "BEST EFIS" for every person. Some may lead you to believe so, but that is a dubious position to take. For example, in some countries equipment has to be TSO'd to fly IFR so those builders choices are very limited. Luckily most of us are blessed with the ability to choose from multiple providers of very good equipment. The best thing I can tell you is to either visit with someone who has experience with multiple brands of equipment, and also go fly behind it. It's of little value to base a selection opinion solely on the recommendation of a person who only has experience flying behind one system. In the end I could (and have) write many pages on this subjecct, but again the reality is that whichever system you choose you'll be happy with. All of the aformentioned mfgrs (AFS, Dynon, Garmin, GRT, MGL) offer equipment at various levels of price points, various functionality and all offer excellent support. All of them have things that make them attractive to various people and their needs. Depending on your budget, type of flying, experience, etc.. there would be differing products to match your requirements. Some people also have differing backgrounds when it comes to actually understanding bits/bytes and electronics behind the scenes. I'm not that technical, but some people are.

Anyway, this may turn into yet another heated debate as I've already seen some comments here that probably just aren't adding any value to the discussion at all. Like Paul said - the two of us talked about 90 minutes on this subject at OSH and couldn't recommend a single product for everyone. No need for anyone to get personally defensive....it isn't productive. EFISes are much like cars...it's neat that there are alternatives. Can you imagine if we were all forced to buy the Trabant in one of 2 variants for a car and didn't have a choice (like many of our friends in the DDR had it for years)!?!? Fine for some, but not all.

Just my 2 cents as usual!

Cheers,
Stein
 
Speaking from a professional pilot stand point that gets to play with the some of the greatest pointy jets in the military, I'll tell you that I'm completely facinated by the Dynon Skyview setup. I'm mind boggled by the capability they keep coming out with vs. the cost. I'm no where close to building the panel yet, but I can't stop planning it out in my head.

From researching this board, GRT seems to be universally loved by everyone that uses it.

YMMV
 
I have the sky view auto pilot (which is integrated) as my back- up. My primary auto pilot for IFR is ME .... For hard IFR (whatever that is) i'd like to add a second engine, prop, two extra batteries, anti icing, two hand held gps (with a set of extra batteries for each) an extra transponder, ballistic parachute, and extended range fuel tanks cause flying without this stuff is really scary! Oh yeah dual weather, storm scope, radar and a qualified and current NFO in my rear seat.

Dynon sky view is working out very well and has great customer support and will fly IMC as long as I have take off enroute and terminal weather required to complete the flight - auto pilot will remain off until I need to eat my sandwich.
 
Well...food for thought. Thanks for you insights on this matter. I understand that there really is no clear winner in this category so more research is needed. In any case, replacing my BMA Efises, engine pod and autopilot WILL happen this winter. Boy, what a waste of money!
RV8R999, If all these gizmos are needed, I recommend your fly IFR in days of CVU weather ONLY......;):p and yes Dynon is a strong contender along with a good autopilot on the left seat.
 
Redundancy?

It seems to me that two EFIS with integrated AP offers far more capable redundancy than one EFIS plus a stand-alone AP - at approximately the same or lower cost.

Bearing in mind Vern's comments, this is only useful if there is 'fail-over' capability, for the AP and any other 'headless' avionics, between the two EFIS. However that kind of capability is now common enough. I know that the MGL range (which is the only range I am familiar with) can do it.

But how far are we going to take this requirement for redundancy? We do have dual servos on both axes don't we? No? Then, my friends, our redundancy scheme is only half baked. What makes us think that the instrument head is the only part of the system that is going to fail?

Me? I'm flying for sport, so if an EFIS or a servo (or anything else) goes while I am up there, the first line on my plan is to hand-fly the thing safely onto the ground, asap, until I understand what is going on. That is regardless of any redundancy I may have.
 
Denok; I understand that there really is no clear winner in this category so more research is needed. In any case, replacing my BMA Efises, engine pod and autopilot WILL happen this winter


I am currently going through the same scenario. I have the plane down for other reasons so I pulled the BMA units and am in the process of replacing them.

Some other factors to consider in your search for a replacement.

I first looked at what would come close to the functionality and bells and whistles the BMA units had and found no single unit that made me happy.

Second was what unit/units could I put in my panel without rebuilding and rewiring the whole **** panel. Third was cost.

I really like the looks and features of the skyview and it's autopilot and the fact they are giving a nice credit for BMA cores but none of their units would fit in my existing panel without major modification. Pricewise this would probably be the best option for me as well as provide acceptable functionality.

I finally settled on the G3X/GX autopilot and a Tru Trak ADI. The G3x and a Garmin 420 I have fit nicely where my BMA sport was and the Tru Trak ADI bolted right into the hole where the BMA Lite was. I removed a small analog altimeter and the GX AP bolted right into it' hole. The servos will fit nicely where the BMA servos were. While I really couldn't afford this route it was what was best for me and would get me back in the air the quickest so I raided a fund I had built up to rebuild an old 8 series BMW I have in the barn and bit the bullet. The BMW will just have to wait a couple more years.

Same goes for Grand Rapids except no trade in for BMA with them. If you are considering the skyview better talk to them soon as I do not know how much longer they will take the BMA units in trade.

Another option is to just watch e bay and buy up a couple of Blue Mountain units at good prices and put them on the shelf as plug and play replacements. I suspect there will be many for sale in the coming year.
 
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I
Same goes for Grand Rapids except no trade in for BMA with them. If you are considering the skyview better talk to them soon as I do not know how much longer they will take the BMA units in trade.

GRT is currently offering $1k off a HX with a BMA trade in.
 
I see a post back there thinking I and or others are taking a shot a Bob and his opinion.

For my last post I must explain it was not an offensive attack at Bob, we exchange pleasantries and emails off the boards and it is not at all what my post was about.

I was and still am questioning the logic behind his comment or anyone else that makes similar statements.

Just because its integrated does not mean a failure should kill you. Heck if you are VFR only.....who cares, you do not need an AP or an EFIS, but they make mighty good ASI's VSI's and Altimeters.

Now back to redundency, you are not likely to install two sets of servo's and AP's, although you could. So if you lose your AP...so what. If you are VFR and lose your EFIS and hence AP....so what.

Now if you are in IMC and lose your AP....so what, hand fly and land ASAP in my opinion or get out of IMC as soon as you can safelly do so.

If you are in IMC and you lose your EFIS/AP......well you revert to your standby EFIS or A/H etc and hand fly, refer last paragraph.

So for the folks who are a bit offended by other folk like me being blunt.....IFR flight is a serious business, time to harden up or get out!

As Paul has mentioned already there are countless threads on all sorts of angles on this topic, what scares me the most is the though process people use to determine their systems.

I am sure Stein has a long list of war stories he could tell.

DB :cool:
 
... I would personally avoid integrated APs, but then that is a risk decision that you'll need to decide for yourself...
There are a LOT of advantages to having an integrated AP. Enough so that I think I like the idea of my AP knowing if I'm upside-down, in an unusual attitude, etc.

Imagine if you would, you get the plane upside down and then try to engage the AP. As the plane starts to loose altitude, a standard AP MIGHT just pull back on the elevator, causing a split-S. However, an AP that knows you are upside down MIGHT not do that. It MIGHT roll you right-side up before recapturing the proper altitude.

I'm not saying that any particular EFIS/AP combo will do this but just imagine if you designed an integrated EFIS/AP, how would you code it?

As Bob said, ?you?ll need to decide for yourself.?
 
I went with AFS because it offers "ME" the best of both worlds. The EFIS integrates very nicely with my Tru-Trak, adding AP features that others don't, while also allowing me to utilize my AP independently from the EFIS in case of a EFIS failure. Wow, no dual screen needed!

I personally don't care for having all my apples in one box like Garmin 1000/900 units. I've heard/read stories of this units going black. I guess that's why they still install steam gages and carry hand-held radios for backup.

I would suggest doing your own research and talk with each vendor directly. Just make sure the features they claim actually exist and their demo pictures aren't just clever mockups.
 
I was and still am questioning the logic behind his comment or anyone else that makes similar statements.

My comment was more related to risk management with everything running as a single platform in which code in the EFIS is controlling everything.

While the risk may be small due to current hardware and software practices, I choose to mitigate that risk by having the EFIS and AP independent and by different vendors. I choose not to have a software bug or hardware failure take out all the systems. Independent systems will still function in a known state.

Everyone needs to determine all potential failure modes, determine what risk each failure will generate, then determine if that risk requires mitigation for their desired mission. There isn't going to be a one size fit all to risk management.

Paul Dye wrote a great article on Equipment Redundacy - What is Enough? It was originally published in the RVator and later re-published by EAA 9 with Paul's permission. The link is to EAA 9's newletter. It's a good place to start for those designing a panel.
 
Me too.

My comment was more related to risk management with everything running as a single platform in which code in the EFIS is controlling everything.

While the risk may be small due to current hardware and software practices, I choose to mitigate that risk by having the EFIS and AP independent and by different vendors. I choose not to have a software bug or hardware failure take out all the systems. Independent systems will still function in a known state.

Everyone needs to determine all potential failure modes, determine what risk each failure will generate, then determine if that risk requires mitigation for their desired mission. There isn't going to be a one size fit all to risk management.

Paul Dye wrote a great article on Equipment Redundacy - What is Enough? It was originally published in the RVator and later re-published by EAA 9 with Paul's permission. The link is to EAA 9's newletter. It's a good place to start for those designing a panel.

I took that approach as well, but it wasn't a primary concern - cost was. It was cheaper with my panel to use another vendor for my backup platform, in my case AFS 3500 is the primary and Dynon D60 does backup duty. But is reassuring to know a single weak link in a given EFIS doesn't have the potential of wrecking my whole day...

FP08052010A0003C.jpg
 
I choose not to have a software bug or hardware failure take out all the systems. Independent systems will still function in a known state.

This gets in to an area I work with quite a bit, safety-critical software. I'll spare you all the definitions of what constitutes a "hazard", etc., or even what we mean by "safety-critical" (versus "mission-critical", and so on).

This probably doesn't really mean much for what are pretty simple systems (EFISes) by comparison, but there have been considerable studies done on the idea of "different software done by different teams". What was found was that the teams made the same sorts of design "errors", or more properly, failed to deal with unsafe conditions *in the same way*.

Here is noted expert on software safety Nancy Leveson from MIT:

To cope with software design errors, “diversity” has been suggested in the form of independent groups writing multiple versions of software with majority voting on the outputs (like modular redundancy in hardware). This approach is based on the assumption that such versions will fail in a statistically independent manner, but this assumption has been shown to be false in practice and to be ineffective in both carefully controlled experiments and mathematical analysis [14,15,16]. Common-cause (but usually different) logic errors tend to lead to incorrect results when the various software versions attempt to handle the same unusual or difficult-to-handle inputs. The lack of independence in the multiple versions should not be surprising as human designers do not make random mistakes; software engineers are not just monkeys typing on typewriters. As a result, versions of the same software (derived from the same requirements) developed by different people or groups are very likely to have common failure modes—in this case, common design errors.
In addition, such redundancy schemes usually involve adding to system complexity, which can result in failures itself. A NASA study of an experimental aircraft with two versions of the control system found that all the software problems occurring during flight testing resulted from errors in the redundancy management system (which was necessarily much more complex than the original control software). The control software versions worked perfectly [17].​

Software Challenges in Achieving Space Safety by Nancy Leveson. Journal of the British Interplanetary Society, Vol. 62, 2009

Do not think that if you have some sort of non-internal fault as your "hazard" that *both* systems will not fail to handle the condition in a safe manner.

Now, a problem with an OS, or a circuitry problem, or something like that, yes...but then, that alone wouldn't require independent vendors, would it?

Further, safety is an *emergent property* of the system as a whole, and cannot be evaluated on a component-by-component basis. And that system includes your vehicle, you, the ground components, etc.
 
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Steve, you bring up an issue I've been looking at for some time and still don't have the correct words to verbalize it succinctly.

Here is what I?m thinking:

Which is safer, airplane A or airplane B?

Airplane A:
Primary and backup flight instruments, electrical system, etc.
Either two EFIS units or an EFIS unit with steam gauge backups and multiple electrical power sources, including dual batteries and generators. This includes the required wiring designed to limit back feeding/battery draining situations and the necessary switches to control it.

Airplane B:
One set of flight instruments, either steam gauges or an EFIS. Simple electrical system with no ?E-Buss? or backup battery.

When Airplane A has a problem, how much time does the pilot spend resolving the conflict and getting on with the business of flying vs. Airplane B?

Could the complexity of Aircraft A when something goes Tango Uniform actually make for a less safe aircraft when compared to the simple Aircraft B? When something goes wrong with Aircraft B, the pilot has to get on with flying whereas the pilot of Aircraft A may spend more time trying to debug a situation, which could be fatal.

Thoughts?
 
Shouldn't these last couple of posts be a new thread?

I agree - of course, there are NUMEROUS threads on the topic of redundancy that they could have been tacked on to....I don't remember how to split threads, or I'd do it for you guys. Not trying to stop discussion, just pointing out that you're not really addressing the question of the OP on THIS thread.

"Play Ball":D
 
There are a LOT of advantages to having an integrated AP. Enough so that I think I like the idea of my AP knowing if I'm upside-down, in an unusual attitude, etc.

Imagine if you would, you get the plane upside down and then try to engage the AP. As the plane starts to loose altitude, a standard AP MIGHT just pull back on the elevator, causing a split-S. However, an AP that knows you are upside down MIGHT not do that. It MIGHT roll you right-side up before recapturing the proper altitude.

I'm not saying that any particular EFIS/AP combo will do this but just imagine if you designed an integrated EFIS/AP, how would you code it?

As Bob said, ?you?ll need to decide for yourself.?

Bill,

With respect, I wonder if you are the same issue? Any autopilot must know the attitude of the airplane to properly perform its task. The best gyros to do that are those specifically designed for the task - eg those fitted to a standalone (but linked up) autopilot. The gyros in an EFIS are designed to provide you with information to control the airplane. The two tasks are different. They might sound very similar, but are not, and require the gyros to be optimised in different ways (or probably the software that interprets the outputs from thegyro pack to be optimised in different ways). To be very useful the AP needs to be hooked up to the EFIS to receive nav requests - so linked to the EFIS yes, integrated with (and using the same gyros as), no.

Pete
 
An autopilot need not know the attitude of the plane at all. It's totally possible to make an autopilot with just a turn rate gyro and an altimeter. It would have no idea if you were upside down or doing a flat turn with the rudder.

The goal of an autopilot is to hit a heading (track) and an altitude. All it needs to know if you are left or right of your heading and above or below your altitude. It doesn't need to care how you get there as long as the error is zero.

Of course, if it doesn't have EFIS data, it can't limit pitch or roll angles, and if it's upside down, it will do the "wrong" thing. But in normal conditions it should be able to fly the plane just fine.

None of this is meant to be an argument for or against an EFIS integrated AP, but call up Trio or TruTrak and ask them if their autopilot ever has any idea if your plane is upside down, and they'll tell you no, the AP doesn't need to know attitude to fly an airplane. Clearly you can make an excellent AP without knowing attitude since they both do it.

What is interesting to consider is what your "standalone" AP really needs to keep working. How long can it hold a heading and altitude with NO external connections? Does it need GPS to work? If it needs external data like a GPS to perform, and your EFIS is a GPS and PFD in one box, then do you consider yourself to have redundancy? Can it be power cycled in flight and still perform? Does it know when a servo has failed?
 
An autopilot need not know the attitude of the plane at all. It's totally possible to make an autopilot with just a turn rate gyro and an altimeter. It would have no idea if you were upside down or doing a flat turn with the rudder.

The goal of an autopilot is to hit a heading (track) and an altitude. All it needs to know if you are left or right of your heading and above or below your altitude. It doesn't need to care how you get there as long as the error is zero.

Of course, if it doesn't have EFIS data, it can't limit pitch or roll angles, and if it's upside down, it will do the "wrong" thing. But in normal conditions it should be able to fly the plane just fine.

None of this is meant to be an argument for or against an EFIS integrated AP, but call up Trio or TruTrak and ask them if their autopilot ever has any idea if your plane is upside down, and they'll tell you no, the AP doesn't need to know attitude to fly an airplane. Clearly you can make an excellent AP without knowing attitude since they both do it.

Of course you are correct that a rate gyro based autopilot is possible and will work adequately (S-Tec did it for years), but why would you not want to know? It will provide much better performance in both axes.

Pete
 
Denok. I will try to get this thread back on track..
Sorry about your BM. I too had a G4 lite plus with AP. I loved the design and UI. I looked at GRT and Advanced but settled on Trutrack EFIS with the AP4.
I liked the simple but Very powerful user interface over the fore mentioned.
Coming from BM you can understand.
While the TT EFIS does not have synthetic vision I found I really did not have much of a need for it and I really had no need for the complex interface the others have to offer.
I defined my mission as needing a Rock Solid AP, A EFIS that displayed the necessary information required for safe and reliable IFR flight, And a system that did not need a book to operate especially when **** hits the fan in IMC.
Every command on the TT is just one button press. One button for ILS coupling. One button press for GPSS approach, One button for simple wings level and alt hold. No sub menus to get lost in.
All the procedure approaches that it does are silky smooth even in the rough stuff.
The screen is uncluttered and easy to read with just a glance and has everything you need for IFR. Integration with the 430W is flawless.
My system with the AP4 is in every way the same as the sorcerer with a EFIS as its control head.
This is just a suggestion as you might have different missions from me.
I just did not want a display that had more bling bling than my mind could wrap around.
Also I trust the TT EFIS in IMC more than I trust myself.....


PS I will extend an offer to fly my RV7 if you are ever in iowa. "KIKV" You should try b4 you buy. Where are you located?
 
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Just another comment on AP if I may (since it has been mentioned).
Yes, it is possible to make an AP with a single axis rate gyro (usualy mounted at a 45 degree angle so it measures both yaw and bank rates - but can't tell the difference) and a pressure sensor for the altitude.

But it can go further as well. An AP that has the "full picture" so to speak would be able to level your aircraft from any attitude provided the algorithms are written to recognise the attitude and know how to correct.

Those that our flying our AP can engage at any attitude and the AP will try to get you straight and level. This works slightly better with the MGL servos than the Trio servos (when connected to our AP) as they can respond faster.

You can see the effect without trying it on a real aircraft if you fire up our EFIS simulator and connect it to Microsoft Flightsim. Once you have everything setup and the AP dailed in (select the Trio servos for this, they are "faked" for the Flightsim interface), simply place the aircraft (I like the Baron, it seems to work fairly realistically) in any attitude you can think of and engage the AP - then sit back and watch...

I'm not saying this has realistic value - this is not the function of a traditional autopilot system which is more a flight path stabilization system than anything else. But it's fun anyway and why not ?

Rainier
CEO MGL Avionics
 
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