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-   -   Single ADAHARS, Single big Screen and IFR (https://vansairforce.net/community/showthread.php?t=145091)

BobTurner 12-28-2016 12:16 PM

You guys can rationalize all you want, but the actual experiment has been done, and reported here on VAF: light icing, airspeed fell off but did not go to zero, Dynon did not auto-switch, display showed false horizon. Since I bought my panel when there was no GPS backup, and loss of pitot data was a known problem with Dynon, it was an easy choice for me to buy GRT. The choice now is harder. But everyone should be aware of the compromises involved.

GalinHdz 12-28-2016 01:35 PM

Quote:

Originally Posted by BobTurner (Post 1137309)
You guys can rationalize all you want, but the actual experiment has been done, and reported here on VAF: light icing, airspeed fell off but did not go to zero, Dynon did not auto-switch, display showed false horizon. Since I bought my panel when there was no GPS backup, and loss of pitot data was a known problem with Dynon, it was an easy choice for me to buy GRT. The choice now is harder. But everyone should be aware of the compromises involved.

I think we may be talking the same thing but from a different point. I had a similar issue back in 2012 with my D6 with no GPS connected. Rolling down the runway, airspeed accelerated slowly to 35Kts then stopped even though I knew we were still accelerating. I aborted the takeoff, taxied back and parked the airplane with the airspeed still indicating 35Kts. At the time I did not notice if the attitude was correct or not.

I disassembled the Pitot system and when I blew into the tube connected to the Pitot, a small dead ant flew out. Apparently the ant crawled in, partially clogged the pitot tube making the airspeed accelerate slowly. Once the ant was fully jammed in, the clog was complete and the airspeed stayed at 35Kts until I released the built up pressure by opening the system.

Needless to say I immediately connected the GPS to minimize this happening again. I was very lucky to be rolling down a 7,000ft runway which gave me time to realize something wasn't right and abort.

:cool:

fangohang 12-29-2016 02:45 AM

Quote:

Originally Posted by N804RV (Post 1136185)
Seriously thinking about foregoing the double redundancy for PFD.

My thinking is, I'd have a single large screen (with a single ADAHARS and an EMS), a GTN650, and a small, inexpensive, self contained basic EFIS as a backup and maybe save a few dollars and some panel space.

Is anyone else doing this?

I'm new to the RV world nbut like your solution. How much are you budgeting for your avionics? Are you planning to be ADSB 2020 compliant and IFR? You thinking D6 for the Independant system?

Thanks in advance for your patience.

rleffler 12-29-2016 05:47 AM

Quote:

Originally Posted by fangohang (Post 1137455)
I'm new to the RV world nbut like your solution. How much are you budgeting for your avionics? Are you planning to be ADSB 2020 compliant and IFR? You thinking D6 for the Independant system?

Thanks in advance for your patience.

I've found that a good rule of thumb is 30% for the kit, 30% for the engine, and 30% for the panel seems to work. At least for the RV-10s.

Your mileage may vary depending on your mission, requirements, and if you buy used or get exceptional deals.

Yes on the ADSB and IFR. There are other options available today than just the D6, such as the Dynon D2, Garmin G5, and the Trutrak Gemini PFD. I'm sure that there are others.

N804RV 12-29-2016 04:10 PM

Quote:

Originally Posted by fangohang (Post 1137455)
I'm new to the RV world nbut like your solution. How much are you budgeting for your avionics? Are you planning to be ADSB 2020 compliant and IFR? You thinking D6 for the Independant system?
Thanks in advance for your patience.

Hey Steve.

I'm still thinking it over. But, like rleffler said, 1/3 airframe, 1/3 FWFWD, 1/3 Avionics/instrument is a good rule of thumb to start with, I think. And, that's probably only if you paint it yourself.

I'm planning on being ADSB 2020 compliant and IFR capable. So, I'm real close to just biting the bullet and getting a home equity loan in order to install all the bells & whistles.

Got a ways to go yet. So, still haven't decided on avionics yet. Maybe by this time next year.

If you really want a $ number, I'm thinking its gonna cost me at least $18K for avionics/instruments. But, that's not a hard number right now.

Kyle Boatright 12-29-2016 05:10 PM

Quote:

Originally Posted by N804RV (Post 1137630)

If you really want a $ number, I'm thinking its gonna cost me at least $18K for avionics/instruments. But, that's not a hard number right now.

18K will get you a single screen G3X touch with autopilot servos and engine sensors. It will also get you a remote mounted Garmin com (GTR20), audio panel (GMA245), remote ADSB in/out/transponder unit (GTX45), an autopilot controller, and Garmin's WAAS GPS for the ADSB out. It'll also buy you the mounts and harnesses for all of that equipment. This is first cut (i.e. non-negotiated) pricing from the likes of Stein, Stark Avionics, etc.

To that, you need switches, annunciators, fuses, breakers, etc. plus any upgrades like backup batteries.

You won't be IFR at that price unless you find an IFR navigator on the cheap. And you won't have any backup capability. Figure another $5k (at least) to add that capability with a GTN625 and a G5X.

Don't forget an ELT.

Wiley 05-15-2018 04:27 PM

skyview failure mode
 
I thought this would be a good addition to this thread.

I have a Classic Skyview 7" display with a single ADAHRS. I have 300 hours on the installation and plane. Fly VFR only. Flying at 10500 over water last weekend, the AP dropped out and I got an overspeed warning for 511mph. The AI was erratic. GPS ground speed and navigation, as well as altitude remained functional and matched my G396 backup.

At the time, I did not want to reboot the system as I was stable and currently over water.

After landing, Dynon tech support felt it was the ADAHRS that went TU and overnighted a replacement. All is well.

I would have assumed the unit would have realized the failure and used GPS as a backup and flagged it as such. Instead, I listened to "overspeed" every 3 seconds for an hour until landing with airspeed showing around 511mph.

flightlogic 05-15-2018 05:41 PM

A Grand Rapids mini is low cost insurance. Or even TWO. That might be what I saw on Widgets panel.
And the self contained autopilots like Trio just keep on flying.... don't need no stinking gyro. (or ADAHRS as the case may be)

MConner 05-15-2018 08:02 PM

Back up attitude
 
I just bought a -10 that has a 3 screen G3X with one ADAHARS and fly IFR a lot. My choice was to add a G5 with backup battery. The G5 will back feed the G3 displays with data if the ADAHRS 1 fails and will provide over 3 hours of attitude even if the alternator fails and the ships battery has been depleted.

That?s enough to offer a 24,000 hour pro a comfortable redundancy, your mileage may vary.

Mark


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