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TruTrak Gemini PFD Pirep / Feedback

Not so. On the way home from OSH I discovered we have a static leak. Opening and closing avent would result in a 300 fpm climb/descent nearly instantly. Interestingly enough the Gemini will show a climb and keep showing a climb which tells me its just a VSI. As far as I'm concerned that's fine as long as one understands how the instrument operates. In a skidding turn it will flat out lie to you. 30 degrees of right bank with quite a bit of left rudder will show a left turn.

Yes it is so...hold the thing in your hand and pitch it up and down...it shows instant gyro based pitch attitude. It will then slowly transition to VS if you hold it in one position. A change in VS will give you an instant VS indication like you saw but it definitely also factors in instant Gyro data as well.

A static leak should not cause the Gemini to show a constant climb. I would have to see this one for myself to understand that statement.

You described a slipping turn not a skidding one.

The Gemini and all of TT's ADI based products have been explained many times by TT for years now. They are not intended to provide 100% accurate indications for all of the weird positions a person can get an airplane in if they try hard enough but the indications they do provide can guide you just as well as traditional instruments as long as you stay withing their pitch and roll limitations.

If an instrument rated pilot cannot keep the greasy side down with a TT ADI type display, they are not qualified to fly in IMC with any instrument.
 
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I'll video it, it does what I'm saying. It stays put showing a climb. I was surprised by it. If it transitions to the gyro rate its very slow.

Sorry used the wrong term for slipping turn.

I like this instrument and would trust it but I think the algorithms and filtering/averaging in the software is more robust in a Dynon.

What concerns me about this instrument is if one had a sudden unusual attitude in IMC there would be a period of time that even if one knew the "pecularities" of the Gemini that it might get themselves in even more trouble. It gets seriously confused immediately after a roll or loop but rights itself in a few seconds.
 
Gemini

The Vertical Speed is indicated via the horizontal lines of the attitude display.

Since the attitude display is instantaneous gyro info that transitions over time to vertical speed, once you have a vertical speed established, the attitude display is vertical speed.

2vafins.jpg


The arrow in the above pic is pointing at the 1000ft/min up indication for VS. The scale of the VS indicator changes depending on air speed.

In the video, starting at around 8:35:00, you can see me do a few ups and downs and cans see how the VS indication works when compared to the Dynon.

WoW! Is this a novel approach to displaying VS? Never run into it before, always preset markings showing degrees nose up/nose down. Would you think it would be difficult to adapt to? Probably not is my guess... I can't get over how slick a presentation this is for such a small package (and price).
I have watched your video 7 or 8 times (starting to get a bit nauseaus), very good, informative stuff. ;)
 
WoW! Is this a novel approach to displaying VS? Never run into it before, always preset markings showing degrees nose up/nose down. Would you think it would be difficult to adapt to? Probably not is my guess... I can't get over how slick a presentation this is for such a small package (and price).
I have watched your video 7 or 8 times (starting to get a bit nauseaus), very good, informative stuff. ;)

Sorry for the crappy video, its the best I could do with a handheld Iphone and keeping my eyeballs outside looking for other airplanes....the phone case I was using at the time caused that flare from the Sun....have a new case now with a much larger opening for the camera....
 
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Dimmer not so dim ?

I have my Gemini hooked up to the Van's dimmer and when turned all the way down, its still fairly bright in the garage. Definitely dims quite a bit, but compared to the Skyview and my GTN, its still bright.

Any real world experience with the Gemini at night?

Thx
 
What concerns me about this instrument is if one had a sudden unusual attitude in IMC there would be a period of time that even if one knew the "pecularities" of the Gemini that it might get themselves in even more trouble. It gets seriously confused immediately after a roll or loop but rights itself in a few seconds.

I have a Trutrak EFIS, which works the same as the Gemini, and like it very much. Its definitely different than everything else though. Most systems show attitude and leave it to the pilot to figure out what the resultant flight path will be. The Trutrak instruments shows your flight path directly, without the need for interpretation. I think the most confusing aspect of this approach is that it doesn't conform to the legacy technology that most of us trained with. If you think about it though, doesn't it seem a bit strange that all other EFIS instruments emulate a mechanical device designed in the 1920s? Would the gyroscopic attitude indicator ever have been developed if an instrument that displayed actual flight path had already been available?

Regarding unusual attitudes, I've tried this with the Trutrak and found its performance to be on par with a vacuum gyro and with "another leading brand" EFIS that I had previously installed. None were perfect but all seemed "good enough" to safely recover.
 
Watching for the 780

I have a Trutrak EFIS, which works the same as the Gemini, and like it very much. Its definitely different than everything else though. Most systems show attitude and leave it to the pilot to figure out what the resultant flight path will be. The Trutrak instruments shows your flight path directly, without the need for interpretation. I think the most confusing aspect of this approach is that it doesn't conform to the legacy technology that most of us trained with. If you think about it though, doesn't it seem a bit strange that all other EFIS instruments emulate a mechanical device designed in the 1920s? Would the gyroscopic attitude indicator ever have been developed if an instrument that displayed actual flight path had already been available?

Regarding unusual attitudes, I've tried this with the Trutrak and found its performance to be on par with a vacuum gyro and with "another leading brand" EFIS that I had previously installed. None were perfect but all seemed "good enough" to safely recover.
I have been keenly interested in the Gemini PFD as I plan to purchase the 780, if and when available.

The above perspective is bang on once you really step back and think about it. The required reprogramming may be us 20+yr pilots, not the instrument.
 
I have my Gemini hooked up to the Van's dimmer and when turned all the way down, its still fairly bright in the garage. Definitely dims quite a bit, but compared to the Skyview and my GTN, its still bright.

Any real world experience with the Gemini at night?

Thx

You should be able to dim it to a point where the backlight basically turns off. Check the voltage on the dimmer pin as you run from one end of its range to the other. Let me know what you find. Be aware that at the low end ~0-1v, the backlight will return to full intensity.
 
Feedback on the Trutrak Gemini unit

Looking for the good and bad points about the Gemini unit has anyone have anything to tell me about it??
 
The unit is compact and very light and easy to use.

The screen is high res and easy to see even in direct sunlight since it is a transflective screen.

TT is releasing a major firmware revision on 10/29.
Contact TT for more details on that.
 
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i am waiting for the updated version due out soon...

have the less-fancy PFD version in the airplane temporarily until Stein gets me the one Trutrak is perfecting. love the interim version, expect to like the Gem even better.
 
My goal in purchasing and installing a TruTrak ADI was to dump the entire vacuum system while keeping the functionality and redundancy of my existing vacuum gyro horizon and DG. Of course these days you get more with glass, even with the basic ADI. Its functionality replaces both gyros and the turn coordinator, and even adds ROC. I was also hoping to sell all my existing vacuum stuff for about what the TT cost. I came close.

IMG_0226.jpg
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All of the vacuum system components together weighed about 14 pounds, and took up considerable space behind the panel, and a little under the cowl. Much less crowded now.
Not to mention no maintenance.

IMG_0590.jpg
[/IMG]

Some things I learned: The TT ADI is very dependent on pitot ? even for roll. The much discussed pitch transitioning to a ROC indication was something I didn?t think I?d like. Turns out it?s very easy to fly. Just keep the difference in mind. A side benefit of this is there is no pitch adjustment, and panel tilt doesn?t make any difference. Very visible in direct sunlight. Most flights since this upgrade include me checking the compass, and trying to set the absent vacuum DG (several times). Tough habit to break


I did want to take advantage of the DG feature when no GPS signal is available, so I included a toggle switch to open that circuit.


Most of my install time was spent on the dimming and backup battery solutions. I did my own backup using 2, 9V duracells. I gave up testing battery life after 2 hours with plenty of life left. My existing panel dimming was of the adjustable pulse width type, which doesn?t play well with the TT. It needs a variable voltage signal, and TT recommends using a potentiometer. However, the ADI doesn?t really dim to a level where it?s hard to see at night, so I just used a simple push on/push off switch (feeding an adjustable voltage circuit) for maximum dimming whenever dimming is needed (I think max dimming occurred at a little less than a volt). I do wish it dimmed some more.

I made a little control panel to hold all these switches, which also conveniently covered up the hole where the suction gauge used to live. Sometimes it all works out!

IMG_0617.jpg
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Have mine on the bench working... Can't seem to make the touch screen respond...I'm following the instructions. Is there something I'm missing...??
Sheldon
 
Well... thought all was ok... Put it in the plane and again, the touch screen won't respond.. Flew just to make sure the gps signal to it and pitot/static, etc. all were working.. Yes.. followed the gps just fine.. Tracked the airspeed right on, etc.. but still could not set the altmeter for the touch screen did not respond.. Have a call into TT.. Will see what they want to do...
Will keep you posted..
Sheldon
 
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Well... thought all was ok... Put it in the plane and again, the touch screen won't respond.. Flew just to make sure the gps signal to it and pitot/static, etc. all were working.. Yes.. followed the gps just fine.. Tracked the airspeed right on, etc.. but still could not set the altmeter for the touch screen did not respond.. Have a call into TT.. Will see what they want to do...
Will keep you posted..
Sheldon

Hi Sheldon,

I'll go ahead and get another one on the way to you when I have one available. I'll email you with the rest of the details for the return. Thanks!
 
Thanks Lucas... really appreciate your service... Sorry I'm the trouble guy with this..
Looking forward to flying with one...
Sheldon
 
Hello Lucas.. Received the replacement Gemini PFD ok..just been too cold out in the hanger to install it... Hope to do it this weekend (16th or 17th) then will ship back the unit I remove...
Interesting note, I flew 3 different times (weekends) and the touch screen feature didn't work.. However, upon taxing in towards the hanger after my last hour flight, it started to work for about a few minutes... Oh well
Sheldon
 
Any thoughts on using this as a Day/Night VFR Primary Flight Display? Want something a little more than a turn coordinator for flying the vast expanse of west texas at night...

Rex
 
TT Gemini PFD

I see two different display formats, one showing the DG as a horizontal display and the other with the DG in a semi-circlular format like the TT EFIS. Is the second one showing the new firmware that I read about?
 
I see two different display formats, one showing the DG as a horizontal display and the other with the DG in a semi-circlular format like the TT EFIS. Is the second one showing the new firmware that I read about?

No, early out, TT dropped the circular idea and went with the ribbon at the bottom.

This is the way it looks:

GeminiPFD.jpg
 
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Gemini PFD

Thinking about buying Gemini PFD, anyone flying with one of these and if so how do you like it? Pros & Cons, easy install, etc....

Thanks,
Oly
 
We've got one in the RV-6....I flew the airplane from Texas to SnF then to Nevada, and it never missed a beat - backup to the G3X system. I had plenty of time to play with both as we cruised across the country, and their data compared well.
 
loss of gps signal?

I think that this question came up back when digital autopilots first hit the scene.

What happens to the PFD (and/or other similar backup horizon-type devices with pitot/static plus solid state 'gyros' plus gps) when gps is lost? In other words, are these devices dependent on gps for an attitude solution? Could they maintain valid display info long enough to get out of the clouds?

I know that the question implies multiple simultaneous failures, but I'm still curious about the answer.

Charlie
 
I can only answer your question for the Trutrak Gemini series products. It uses the GPS ONLY for the slaved DG and a backup to the airspeed indicator. If GPS signal is lost, the track pointer on the DG tape will turn red. The attitude, airspeed, and altitude are all still functional as the Gemini displays actual indicated airspeed and baro altitude, not GPS ground speed and GPS altitude.

If the pitot input goes dead, the Gemini airspeed tape will turn yellow to indicate it is displaying GPS ground speed and not actual IAS.

I hope this helps!
 
Gemini pressure sensor fix?

Lucas

When can we expect the issue with the PFD pressure sensor issue resolved?

Regards
Bruce
 
Back in early March while re-doing my panel to install my AFS5500, I installed a TT Gemini ADI as a backup attitude reference. I installed it between my backup altimeter and airspeed, so I did not need the PFD version.

The Gemini is everything I needed as a backup ADI and is as advertised. It is quite sensitive in pitch but serves as a good IFR platform. The small pitch lines do not present themselves until you have groundspeed and serve as a VVI in that one line up or down will deliver 500 ft/min climb/descent. It's heading reference along the bottom is actually GPS track and must have GPS input to work.


While doing aggressive maneuvering or aerobatics it lags actual attitude and takes 3-4 seconds to catch up once maneuvering stops. It is an electrical instrument so you must have a battery backup in the system in case main battery/alternator/master switch is out.[/QUOTE

I didn?t discover the attitude lag until after I purchased and installed the PFD.
I don?t think I could trust this instrument for recovery from unusual attitudes in IMC. Had I known that the instrument could not keep up during aggressive maneuvering or aerobatics I?m not sure I would?ve selected this instrument to be installed in my panel as a primary or backup PFD.

My Dynon D10A performs flawlessly for all maneuvers.

The VV for pitch control works amazingly well for maintaining 0 pitch.

Normal maneuvering seems to work just fine.
 
Back in early March while re-doing my panel to install my AFS5500, I installed a TT Gemini ADI as a backup attitude reference. I installed it between my backup altimeter and airspeed, so I did not need the PFD version.

The Gemini is everything I needed as a backup ADI and is as advertised. It is quite sensitive in pitch but serves as a good IFR platform. The small pitch lines do not present themselves until you have groundspeed and serve as a VVI in that one line up or down will deliver 500 ft/min climb/descent. It's heading reference along the bottom is actually GPS track and must have GPS input to work.


While doing aggressive maneuvering or aerobatics it lags actual attitude and takes 3-4 seconds to catch up once maneuvering stops. It is an electrical instrument so you must have a battery backup in the system in case main battery/alternator/master switch is out.[/QUOTE

I didn’t discover the attitude lag until after I purchased and installed the PFD.
I don’t think I could trust this instrument for recovery from unusual attitudes. Had I known that the instrument could not keep up during aggressive maneuvering or aerobatics I’m not sure I would’ve selected this instrument to be installed in my panel as a primary or backup PFD.

This video illustrates the lag issue. PFD has similar behavior following aerobatic maneuvers.
https://vimeo.com/74660635

My Dynon D10A performs flawlessly for all maneuvers.

The VV for pitch control works amazingly well for maintaining 0 pitch.

Normal maneuvering seems to work just fine.
 
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