All certified aircraft flying with glass panels have steam backups. That's
because those aircraft are certified with the steam as primary. The glass is a
backup instrument. I don't think a single ga ac has been certified with the
glass as primary.
This is an interesting statement. I recall a similar statement being posted in a thread sometime back and one poster sent this opinion to Garmin. As I recall Garmin replied and strongly refuted that position and stated that their glass systems are indeed certificated as "primary".
But...in spite of running numerous searches of the forum, I can't find that post. So I guess my recollection will still have to remain in the
suspect file.
You could use the EIS for airspeed if you wanted to. I'll use the AOA
instead when the EFIS goes tu. That tells me everything I need.
Sorta. Its true an AOA indicator is all you need for landing the plane (I rely on the LRI for backup airspeed when landing) but an AOA won't assist in an instrument scan enroute if you end up flying on backup instruments. As all IFR-rated pilots know, the airspeed indicator is an important part of the instrument scan when flying partial panel.
In response to the original inquiry about transitioning from steam gauges to glass, I experienced this firsthand when my RV-6 first took to the air. Even though limited to VFR, the only pitot instruments in my panel were the RMI uEncoder and a small analog airspeed indicator. It took a few hours to get accustomed to reading a digital readout of airspeed, altitude and vertical speed, but once the brain was recalibrated, analog gauges seemed
crude. The analog airspeed indicator was removed from the panel and replaced with the LRI.
Another interesting observation: Because I have used the uEncoder for all ~800hrs in the RV-6, I still primarily refer to it for airspeed and altitude even though there is a Dynon running right above it (the LCD numerals in the uEncoder are larger and bolder). But....I've found that as soon as I put on a hood for some practice IFR, my scan naturally centers on the Dynon and
all pitot info is pulled from it. This is not something I do intentionally, it just happens. Must be some human factor or ergonomic stuff (
fear???) going on that makes me concentrate only on the Dynon when I am forced to fly the attitude indicator.
So, yes, you can adjust to glass instruments, and once the adjustment is made, I don't think you will want to go back to analog. This makes me wonder if the most efficient and most easily grasped setup when in a stressful situation would be duplicate glass backup instruments so our brains wouldn't have to shift gears from glass to analog.