Twin engine dedicated EMS screen

[Danerazz]

Interested in a full-Dynon for my Baron. In the documentation it says a screen has to be dedicated to EMS. One spot says 100% or 50% EMS view at takeoff/landing, then elsewhere it says 100% is normal for all operation in multi-engine.

The older Baron panel does not lend itself to 3-screens due to the power lever location. Can the “dedicated” EMS screen (as in the Baron 58 example photos on the Dynon site) be split 50/50 EMS/PFD?

I’m asking because I want to know what the option is if the main screen fails. If the EMS always has to be 100% I would be stuck with the D30 and zero navigational ability (as far as flying an approach).

Follow up question: why can the bottom EMS strip not be primary EMS for twins, or just a “permanent” 20% EMS side strip on the PFD?

I’m sure this is an FAA requirement for the installation, but Big G systems can be installed for twins with the only EMS info being a primary strip on the side of the 10” display and no other screens installed.

 

[Rhino]

There is no requirement to dedicate a screen to EMS that I can find. It gives you the option, but there is no requirement for it. Are you referring to something in the STC?

 

[Danerazz]

There is no requirement to dedicate a screen to EMS that I can find. It gives you the option, but there is no requirement for it. Are you referring to something in the STC?

It says a “secondary non-PFD screen” must be dedicated to EMS display for twin-engine aircraft.

 

[Rhino]

It doesn't say it has to be 100% dedicated to EMS. 50 % is fine. So yes, you can split it between PFD and EMS. The reason they don't allow less than 50% is because the FAA feels not enough engine data would be easily seen by the pilot. Location and screen/instrument size is a factor in their decision making, and I imagine that's why the larger, front and center, Garmin display can get away with a less stringent requirement.

 

[Danerazz]

Is the 10” Garmin bigger than the Dynon? Just seems like the certification was not equally applied (FAA, not dynon’s fault) but who knows? Maybe there are differences in system architecture for implementing two engine EMSs.

 

[Rhino]

I was thinking of the 12 and 15 inch Garmins.

 

[Danerazz]

I’m comparing to the 10.7” G500

 

[Rhino]

Okay. That makes more sense then. We'd have to ask the FAA what their thinking was. I know they also factor field of view into the requirements. The closer an instrument is to front and center, the less stringent the requirements get. But how they figure all that out is a mystery to me.