miyu1975

miyu1975

Well Known Member
I have seen many debates between dynon and grt glass panels but not many discussing blue mtn glass. Does anyone have any feedback on blue mtn in general? They seem to be a little more pricey than the others. I was considering the Sport Blue Mtn, but I am sure that all function virtually the same..
 
BMA EFIS

I purchased the BMA EFIS/Lite Plus 18 months ago and my RV7 is about a month away from the first flight. I bought both the EFIS and the two axis auto pilot system from BMA and they seem to be OK to deal with. I had to wait several months for the G4 version of the product but it was not a problem due to the RV not being close to flying. With the options available at the time, I am OK with my decision along with the choice of the VMS 1000c engine monitor.

If I were to do it today my decision would be quite different. Go on the BMA web site and scan through the message board to get a feel for what is going on in the field with their products. Some people have had problems.....most created by questionable installations. Several people have had EMI problems with the COM and NAV receivers due to RF being emitted from the EFIS. In testing my systems, I do not appear to have this issue.

I believe I rushed the decision process too eairly in the build and I can only explain how I would do it differently in the future.
1: I would use a modular instrument panel and terminate as many connections as possible in molex and DB-XX panel connectors near the sub panel.
2: Defer the purchase of the Avionics, EFIS, and EMS as long possible.

These are just MY thoughts on what I would do next time and is not an attempt to convince anyone else that this is the best and only way to go.

Lots of luck in your project.
Richard
 
Check out TruTrak

I am also monitoring this situation but it will be ~ another year before I make a final decision. I am currently leaning towards a Trutrak EFIS and and the Dynon 180 as the EMS with an EFIS backup, combined with an SD30 and an SD40. GPS to be determined. Also watching the Dynon synthetic vision with interest. Looked at Blue Mountain but something about it doesn't feel right.

Currently installing a Dynon EMS in my RV4 and as I seeing how that plays out will influence my decision for the Rocket.
 
I did an extensive web search and the GRT came out tops at the time. Dynon was also excellent but not as feature full.
I got scared by Bm as a lot of people seemed to have all sorts of problems with them and the company
Maybe things have changed now. It does look like a nice product .

The best advise is to wait as long as possible before choosing.
My GRT is only 2 years old but outdated already.
But it still does all I need it for.
 
I have 2 BMA EFIS and the AP.

The EFIS units (G3 Lite and G2 Sport) have work for the most part as I thought they would. Keep in mind that a EFIS is just a dedicated PC and we all know how often PC can make us mad.
I have had a major problem with the AP. Some of the operation it does very well most of the time, but some of the operation that it was supposed to do it has never done correctly. For the last two years BMA has been intending to fix the software to correct the AP problems. They have not succeeded yet.
At this point I think that it is not a good system design to have the EFIS unit in control of the AP. There have been a few time that the EFIS has crashed and that caused the AP to go funky on me. One time it tried to do a roll.:eek:
If I were doing my panel again today I would buy the Trutrak AP. That way if the EFIS failed or even needed to have new software loaded, my AP would still be stable.

Kent
 
Opinion about integrated autopilot

The Dynon certainly represents a good bang-for-the-buck with the integrated autopilot and for strictly VFR it may be a good choice.

For me, though, I would stick with an independent autopilot - TruTrak in my case - and let either the GPS or the EFIS give it guidance - switchable. In an extreme case I can even disconnect from the autopilot and use its internal magnetic guidance.

I've had the Garmin 496 lock up on me twice, both times during XC flights. Both times I was able to fix it by removing the battery and re-booting it. Meanwhile, the autopilot just reverted to HDG intstead of TRK. No drama. And the AP took care of flying straight and level while I fiddled with the Garmin.

It's more money and more wiring to do it as I have it with my GRT, but I would not want the EFIS to be in total control of the autopilot.

Just my two cents.
 
A Dynon EFIS + two servos is less than TT's cheapest AP. So if you're looking for a "redundant" AP, why not just buy a second Dynon EFIS and get a whole lot more functions for less money? Ask anyone- nobody has our EFIS units lock up.

We'll revert to internal magnetic data if we lose the GPS feed too. Not sure why having an EFIS "control" the AP is any different than having the TT control head control it. They both have internal magnetic sensors and can use external data to navigate, so in terms of external reliance, they're the same. They both require internal gyros and accelerometers, and a lot of software. The main difference is that we have a LCD screen to show you attitude and a few more gyros to calculate it.
 
Positive BMA experience

I can't speak to the autopilot wholly, yet, because I'm still a few weeks from first flight. Nor can I comment on the other systems. But my EFIS One has been pretty flawless so far. Any problems I've had have usually been a result of the nut behind the screwdriver, if you acquire my drift. I had some difficulty with the AP installation until I finally noticed that the control cable is a Cat5 crossover, then again when I didn't read the ground check procedures carefully. I'll now approach in-flight testing a lot more carefully. The EFIS itself was a breeze to connect sensors to and the engine pod is awesome. I did run into a software problem setting the red range for the fuel, which I am told is fixed in the beta software. On the other hand, I just had the IFR altimeter and transponder checks and we re-calibrated the altimeter settings to the avionics tech's equipment. It was dead easy and then we proceeded to do the check and the tech was amazed that even interpolated numbers were right on. We also checked the airspeed and it was consistently about 4 knots low. Considering that the backup airspeed matched that, it's probably an error in my pitot system and not the instruments.

Customer service-wise, the support has been immediate for answering questions and correcting my mistakes. There was a slight bit of confusion when ordering my engine sensors but they paid to take the wrong ones back and sent me the right ones right away. I, too, am concerned about some of the software issues but as a long time computer and network tech I know that no software is perfect and most faults can be worked around. Consider, for example, the documents that Word is capable of creating and yet you should see the issues on their support site. Moral: 1) Buggy is not necessarily dangerous or unusable and 2) even the best systems have quirks and require the use of the human brain to ensure correct results.

Would I go with them again? Absolutely, unless I could afford a synthetic vision system with integrated TCAS and weather on a single display. I kinda agree with the remark about keeping the AP separate, but the BMA autopilot was so easy to install I couldn't resist. And the hardware is awesome. I've seen the earlier systems with the separate head and those are nice. The G4 systems are just beautiful.
 
Sorry Dynon, but I don't agree.

dynonsupport said:
A Dynon EFIS + two servos is less than TT's cheapest AP. So if you're looking for a "redundant" AP, why not just buy a second Dynon EFIS and get a whole lot more functions for less money? Ask anyone- nobody has our EFIS units lock up.

We'll revert to internal magnetic data if we lose the GPS feed too. Not sure why having an EFIS "control" the AP is any different than having the TT control head control it. They both have internal magnetic sensors and can use external data to navigate, so in terms of external reliance, they're the same. They both require internal gyros and accelerometers, and a lot of software. The main difference is that we have a LCD screen to show you attitude and a few more gyros to calculate it.
Click to expand...

I don't have your product, so can't make claims about it, but just some general statements. I have work with PC/Computers (writing software and working on hardware) for more the 40 years and have the BMA EFIS unit.
The BMA EFIS is a Intel processor running a version of DOS. DOS can crash! The more function that you put into a product/application the more time it takes to run. I have seen time when I was making adjustments that the AP update/guidance got behind.
Also while the EFIS was guiding the AP and I was starting to make a change to the bearing, I hit a bump and my hand jammed into the control knob. This is when the EFIS when on the FRITZS. I saw a number of divide by zero error messages scroll across my EFIS screen, and then the AP commanded a right roll. I didn't have my hand far from the stick and stopped it before going passed 45 degrees of bank. I was thankfully VFR at the time.

The EFIS by definition does a lot of stuff. After all it replaces more than 6 instruments. I would just feel more comfortable with simpler processing going on with the device that flies the plane. Also I don't want to upset the AP with updated software that goes onto the EFIS for bug fixes and enhancement.

Not to say that Dynon doesn't have good support (I think that you guys do a good job), but I guess that you don't remember the early "ROLL" problem with the D10 units. A friend of mine needed Dynon replace parts in the EFIS three time before the "ROLL" went away. The last couple of years he has not had a repeat of the problem. I know that the "ROLL" problem was a problem for a lot of the D10 buyers.

Kent
 
The "roll" issue you describe was not a software problem. It was vibration in the plane causing issues with our gyros. The same gyros the AP guys use. The advantage of our system is that it is field updateable, unlike most of the AP's out there, and we were able to fix this problem in SW.

Company philosophy has a lot more to do with the stability of a system than the processor and/or OS used. It is possible to make a computer that never crashes. They are all around you, in cars (modern cars run an OS), your TiVo, and your cell phone. It just requires careful coding and lots of testing. Saying you once had an EFIS from brand X that wasn't very stable doesn't mean all EFIS units are unstable. Testing is the reason Dynon only does updates about once every 6 months, not every few weeks.

A modern digital AP needs airspeed, altitude, turn rate, vertical speed, pitch rate, magnetic heading stabilized by a gyro, a display, buttons, serial connections to a GPS....

Sounds a lot like a 6 pack, and then some. They aren't really much simpler than an EFIS from a hardware standpoint.
 
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Rumor and K.I.S.S.

Since I only have Dynon I can only speak to that. I like it and support is good. However reading, BMA seems to generate more complaints than most EFIS? This could be old news, long fixed early bugs? I do know early BMA production and wait times generated lots of unhappy campers. Again that me be a thing of the past. BMA does have nice "FORM, FIT, FUNTION" from their ads.

Personally I want a good solid basic EFIS, reliable attitude (Dynon is GPS independent), good flight data (Altitude, Airspeed, VSI, Heading, Rate of Turn).....and good support. All the other bells and whistles are nice but not critical. Superimposing NAV or Map data is nice, but personally I like keeping my GPS nav map display separate and the EFIS doing flight instrument duties only. I think it makes it more reliable and of course cheaper.

GRT is a well respect brand and company. I have their engine monitor gear. GRT I think is best in integration of functions, in that it will accept standard data bus with "real" avionics. I don't have one but have not heard anything bad about the GRT EFIS. Dealing with them for 8 years or more with my engine monitor I find they listen to their customers and make improvements. If I go for a step-up from the Dynon, I would put the GRT at the top of the list.

The folks that design and sell all these EFIS for a few grand to $10K are all to be applauded, very clever folks. Look at the price of "real" EFIS, 10 to 30 times the cost. What's a Garmin 1000 go for now today? The Garmin is better no doubt, but what do they cost? $80k? That is more than my whole plane. Will it make it more fun to fly? Don't get enamored with flashing lights. Are you really going to fly IFR? Day VFR is your prime mission? You can always retro fit/upgrade the panel.

To me, my recreational fun flying is about doing Acro, going into remote strips, formation, travel and practicing pilot skills. I don't really need to stare at a fancy panel in my personal plane. I like looking out the canopy too much. I have lots if IFR time in single engine planes to last me a lifetime. I really don't have the desire to do single pilot IFR, just because I don't need to. If I decide I want IFR capability I will supplement the Dynon with a backup attitude instrument. May be go old school and put a Vac sucker on and an old fashion Vac ATT gyro. Its totally independent for the electrical system, right.

Frankly the older I get the more appealing a J3 is to me, which I have some time in. There is something about flying with out all the electronics that appeals to me. However EFIS is a wounderful thing for our experimental planes. It was only found in airliners 20 years ago. It was less than 8 years ago that BMA and Dynon came out?

The early EFIS in the B757/B767 I fly is pretty basic compared to some of the most fancy new commercial EFIS and "experimental" EFIS on the market. The Honeywell in the Boeing is built like a brick, all business. How much digital display do you need. They did studies of pilots and displays. After so much information, it becomes a burden to the pilot, info overload. Simple displays showing the important stuff that is critical works. A lot of the ergonomics and "human factor" design knowledge has been learned at great cost. Much of that knowlege of displays is incorporated into the experimental EFIS, basically because they copy the displays of commercial EFIS. Than it comes to preference. Try and view different displays in planes if possible. Some are sharper or brighter. Size? I went from a Boeing B737-300 to a -700 with larger screens. Ho humm. I have good eyes and could see both equally well. The larger screens where nice for compacting and combining info, but again the data overload. I turned all the display switches off I did not need and left just what I needed on.

I like the Dynon because it does the job, reliable, low cost and they have good customer service.

Last comment, integration with all Flight, Nav and Autopilot functions in one box seems desirable but redundancy is lower. Having separate FLT INST, NAV and AUTOPILOT has advantage. Of course all these things are electric. So your electrical system takes on new importance if you rely on your EFIS to stay level in IMC/IFR conditions.
 
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Blue Mountain's stuff is attractive. That's why I installed a Lite G3 two years ago in my -7A. I knew very little about the company other than at Oshkosh or on the web. I didn't get the benefit of other's experiences prior to my purchase.

The unit's performance is adequate. Backup instruments are a good idea for EFIS units and mine needs them. The unit's performance led me away from an integrated Blue Mountain autopilot and toward a TruTrak ADI Pilot I, which provides a good attitude backup.

Some promised functionality on the Lite G3 units, such as a second input through the Serial B port, does not and will never work according to Richter, a hardware issue. Purchasers of G3 and earlier units have been given no upgrade path other that to pay up for a later model unit. Software updates have been slow to come to attempt to correct deficiencies, some of which remain uncorrected.

This has been my experience with their earlier units. I don't have experience with their current production. Perhaps you can benefit from developments that I helped finance. It seems that current customers would be a natural market for tradeup sales. The company apparently has a different business model.

You're doing the right thing by mining for information. I suggest that you discount the pretty website and trade show exhibits. Better that you go visit their operation in person and get a feel for their customer orientation. Had I done so prior to my purchase, I would have made a different choice.

Mike
 
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gmcjetpilot said:
I like the Dynon because it does the job, reliable, low cost and they have good customer service.
Click to expand...

Bingo!

There have been many problems with BMA, some warranted, some not. The problem is having a BMA in your plane is a definate disadvantage when it comes time to sell the plane. (Please don't start a war about; "It's my plane and I'm never gonna sell it." You might not sell it but your heirs will have to...someday.) I've seen many planes with BMA's and they just bring a lot lower prices than ones with Dynons. Dynons have had issues also, but their response has been nothing short of fantastic. BMA on the other hand leaves a lot to be desired.

You won't go wrong with Dynon.
 
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BMA works for me...

I've got a BMA efis1 (an old gen 2) in my -6 and it works quite well. Now, admittedly, I only have ~150 hours on it (and the rest of the airplane), but so far, it's a great unit. Engine instruments are flawless, I have no noise on my radio or intercom as others have reported, the airspeed and altimeter at least coincide with my backups, and the autopilot is a marvel to behold, especially in turbulence.

It wasn't always this way, as I had a few teething issues. In the first 5 hours, the horizon would occasionally roll inverted during level flight and then it would sometimes shut down in the middle of a flight. I traced it to a bad power supply that suffered infant mortality. After the power supply got replaced, the flight instruments behaved beautifully but every now and then I'd have issues with the GPS being "off" a bit from where I actually was (like once every 10 hours or so). At 80 hours TTAF, I installed an old used Garmin 196 as a backup and since then, the BMA has worked absolutely flawlessly. The Garmin must have scared it straight!

Support-wise, I haven't had any problems. There has always been someone there that could answer tech questions for me.

Heinrich Gerhardt
RV-6, happily flying
 
I applaud the real experimental guys out there trying things like geared reduction engines and BM even after all the negative coments on the web. [and positive of course]
If you are however like me and dont like "experimenting" too much I suggest you stick to the tried and tested products out there.
I took the safe route by watching the brave who went before me and have had nothing but pleasure from my rv and its systems, efis etc.
 
dynonsupport said:
The "roll" issue you describe was not a software problem. It was vibration in the plane causing issues with our gyros. .
Click to expand...

I would like to second Dynons statement on these gyros - we use them in our SP-4 as well and they don't like vibration too much. It comes down to the quality and location of your installation. Perhaps not surprising, even very expensive systems will demand good attention to issues like this if you want them to perform to their designed specifications.

We use gyros designed by British Aerospace for our SP-5 product (the same you will find in the Crossbow systems) but these are a little more expensive. They are pretty good though and nearly immune to vibration - despite this we still recommend that you pay very thorough attention to your installation.

Just imagine what would happen to a system if it would be allowed to move freely with respect to the aircraft frame (parhaps due to a sloppy mounting) and you fly thorough turbulence - the movement of the AHRS could very easily exceed its maximum rate of roll measurement even if the aircraft is not.
Now, vibration is no different here - it has the same effects but may have additional effects if the vibration contains frequency components that interfere with the operating frequency of the gyro itself (usualy in the range of 10 to 20Khz). This tends to lead to a false roll measurement around the axis in question - and to a horizon image that will be out of whack on your EFIS.
So, bottom line: You need a firm platform, yet isolated against vibration. If you have this, chances are that you will be happy with your AHRS.

Rainier
CEO MGL Avionics
 
Thanks, Dynon

I just want to thank Dynon for engaging us here, it really adds to info available, and wish other vendors would do the same. It no doubt takes time away from other important stuff, but very beneficial to your audience/customers.

Jerry

PS, Just saw you, Rainier, so thanx to MGL as well, your input is very much appreciated.
 
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I have the privilege of being exposed to a whole gambit of EFIS's, that being said... I'd buy just about any of them except the Blue Mountain.



I'll be honest and tell you that I have NOT flown the G4, all of my experience has been with a G3 Lite w/ autopilot. unfortunately my experience has been anything but positive. I have a 2 page write up of gripes that has yet to be even acknowledged by BMA, let alone resolutions forthcoming.



Dynon has for years proven to have a quality product and i don't expect any less from them in thier new offerings.



GRT: same as dynon, great unit. More money, but more options.



Advanced Flight systems: seems to be an outstanding unit. I have not got to fly one yet.



TrueTrak: Everyone (including me) just has to wait and see. They build a great autopilot, will that carry over to the EFIS?



Chelton: Wonderful unit. Way to expensive. ouch.
 
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