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GRT EFIS Survival Tips

Trim calibration

I don't have photos, but I calibrated my trim properly today. It took about 5 mins. It's one of the buried menus, and somehow I had missed it. The defaults had my elevator trim indications reversed. Here are the instructions from GRT:

EFIS Setup:

1. Go to SET MENU> General Setup > ANALOG 1-8 (whichever is wired) and choose appropriate item. Selections are: FLAPS, AILERON TRIM, ELEVATOR TRIM, OR RUDDER TRIM.

2. Turn Pull-Up Resistor ON.

3. Scroll to SET MENU > General Setup > Set Elevator Trim Orientation: Choose DOWN trim at TOP or UP trim at TOP (pilot preference)

4. Scroll to Flap and Trim Calibration. Follow the on-screen instructions to calibrate the indicator on the PFD.

There is also a cool feature that allows you to have "shaded" range in the trim indication on the PFD - I guess this is used to indicate an acceptable band, for example for takeoff trim. I'll try to remember to get pictures next time I'm at the hangar.
 
I don't have photos, but I calibrated my trim properly today. It took about 5 mins. It's one of the buried menus, and somehow I had missed it. The defaults had my elevator trim indications reversed. Here are the instructions from GRT:

EFIS Setup:

1. Go to SET MENU> General Setup > ANALOG 1-8 (whichever is wired) and choose appropriate item. Selections are: FLAPS, AILERON TRIM, ELEVATOR TRIM, OR RUDDER TRIM.

2. Turn Pull-Up Resistor ON.

3. Scroll to SET MENU > General Setup > Set Elevator Trim Orientation: Choose DOWN trim at TOP or UP trim at TOP (pilot preference)

4. Scroll to Flap and Trim Calibration. Follow the on-screen instructions to calibrate the indicator on the PFD.

There is also a cool feature that allows you to have "shaded" range in the trim indication on the PFD - I guess this is used to indicate an acceptable band, for example for takeoff trim. I'll try to remember to get pictures next time I'm at the hangar.

If using trim as one of the aux inputs to an EIS, the beauty is that any EFIS screen that's attached to the EIS via serial link always has a trim position displayed on the screen. Initially I thought only the screen showing engine instruments would show trim - this is not the case. I am really liking how trim shows up on all three of my GRT EFIS screens, irrespective of their mode of operation..

Also note that trim movement, as indicated on the EFIS screen, is heavily damped to ensure it doesn't jump around with electrical noise. This results in the pilot running the trim, releasing the trim button, then seeing the trim indicator is still moving for a short period of time. It takes a little bit to get used to the fact that the trim indicator on the screen "catches up" to the actual trim position.
 
I’m guessing this only works with electric trim, so I’m SOOL with my manual trim RV4. My new GRT equipment has capabilities that may take years to discover (it’s not real intuitive). GRT EFIS equipment that are upgradable to fit with future new standards, and with outside vender equipment, is why I chose GRT, but discovering these capabilities takes a little effort.
 
I'll maybe refine Bob's statement a little bit. If one has the Ray Allen trim motor with built-in position sensing then trim position sensing is part of the trim motor (5 wires... two for motor power, three for position sensing - it's just a slide potentiometer potted into the trim motor assembly). Any other external trim sensor can also be used (can be used to sense position of just about anything from cowl flaps to wing flaps to trim).

It's quite simple to implement - the EFIS is looking for voltage between 0VDC & 5VDC. If you wish to power the trim sensor from aircraft 12VDC then you'll need to make the connection to aircraft 12V, then go through a dropping resistor (suggest that resistor be twice as big as the total resistance value of the potentiometer used in the position sensor - this will ensure the EFIS never sees more than 5VDC) then to the top end of the potentiometer. The bottom end of the potentiometer goes to a good clean aircraft ground (same ground as the EFIS if possible) and the wiper of the potentiometer becomes an analog input to the EFIS.
 
Not sure if this has already been discussed but it is worth repeating.

The EIS alarms can not be muted by pushing buttons on the EFIS. Communication is a one way street from the EIs to the EFIS.

If you do not have easy access to the EIS set up your alarms in the EFIS.

Exception might be oil pressure as it will self clear when the engine starts and if it is set in the EIS, it will then activate the red warning light.
 
Not sure if this has already been discussed but it is worth repeating.

The EIS alarms can not be muted by pushing buttons on the EFIS. Communication is a one way street from the EIs to the EFIS.

If you do not have easy access to the EIS set up your alarms in the EFIS.

Exception might be oil pressure as it will self clear when the engine starts and if it is set in the EIS, it will then activate the red warning light.

Mike,
The exception is the GRT R66 EIS. This remote mounted EIS is controlled completely by the EFIS.
 
Mike,
The exception is the GRT R66 EIS. This remote mounted EIS is controlled completely by the EFIS.

Good to know, wasnt aware of it.

If I ever build another RV10..................

Would be nice if they did that with a 4 cylinder model.

Would be even better if they did/could make a simple software change to allow two way communication with any EIS. Might have to run one wire to make a serial pair for it to work.
 
Good to know, wasnt aware of it.

If I ever build another RV10..................

Would be nice if they did that with a 4 cylinder model.

Would be even better if they did/could make a simple software change to allow two way communication with any EIS. Might have to run one wire to make a serial pair for it to work.

I replaced my EIS 4000 with the R66, works fine with my IO-360. I simply plugged the existing connectors into the R66. I took screen shots of each screen on the EIS4000 before removing it. I then had to input all the settings in the GRT Sport SX EFIS, it was quite easy to do. See the attached picture for an example of the settings.
 

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Winds Aloft Calibration

I have a Horizon 10.1 unit and everything works great except the winds aloft speed is way higher than it actually is. The direction seems to be accurate, but when there is a 15ish kt wind at altitude, sometimes it's reading around 45 kts. I remember in the setup that magnetometer calibration could affect this, but I went through the whole calibration process by the book and had very little error.

Is there anything else I should be looking at??

Marty
 
I have a Horizon 10.1 unit and everything works great except the winds aloft speed is way higher than it actually is. The direction seems to be accurate, but when there is a 15ish kt wind at altitude, sometimes it's reading around 45 kts. I remember in the setup that magnetometer calibration could affect this, but I went through the whole calibration process by the book and had very little error.

Is there anything else I should be looking at??

Marty

Took me a while to find, but look at section 9-3, page 9-5 speaks to the other component to getting winds correct….airspeed. This info is not EFIS specific, hard to find.
http://grtavionics.com/media/Sport-Users-Rev-F.pdf

wind calculation is based on the difference between GPS groundspeed, and true airspeed, it is quite sensitive to true airspeed errors, and for some airplanes a significant improvement in the accuracy of the winds can be achieved by performing this calibration.
 
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