2*G5 will have “2*GPS aiding” 
Ibra wrote:
2*G5 will have “2*GPS aiding”
No, that is for the track! :)
arj1 wrote:
No, that is for the track! :)
Have a read at one of G5 manuals? a proper install should feed GPS position & altitude from Transponder or Navigator, there is an internal antenna and position but the reception quality is weak
http://static.garmin.com/pumac/190-01112-11_03.pdf
The G5 receives a GPS input for attitude aiding via one of the following methods:
• GPS antenna
• GTN 6XX/7XX series navigator
• GNS 4XX(W)/5XX(W) series navigator
• GNS 480 series navigator
• GTX 3×5 transponder
The following functions are provided by the GPS input:
• Ground Track
• Ground Speed (GS)
Maybe here on Post#7 for a serious description “The G5 primary mode attitude solution uses GPS aiding to correct for attitude sensor drift. The G5 has a strong preference for using GPS aiding for the primary mode of operation to be immune from an iced/blocked pitot/static affecting the attitude solution. Some say they can detect a blocked pitot/static affecting the attitude solution, but in reality, this is very difficult, if not impossible, to detect.”
I would not say that I would never rely on an all-electric setup. But I don’t trust actual electronics in a sufficient way.
It’s just a personal feeling, and devices from pre-GPS era may have their defects, but they are primarily designed to improve survival rates. Nowadays electronics seem to have the primary intention to generate happy feelings. I don’t need big monitors. I need to know that I’ll be safe. And although I like my PFD, I am very happy that I have several totally independent means to verify that the data is correct.
I actually don’t feel bad with one electric Garmin AI (actually two with redundant AHRS) and one MidContinent SAM.
Yes, electronic AIs do also fail once in a while – but they fail less often and even more importantly in most situations they indicate that they have failed. Most dangerous feature of mechanical gyros is that they have many failure modes there you realize very late that they actually did fail…
Last time the vacuum pump failed on me I did. Was just descending out of IMC and transiting a military TMA. Interesting.
strange, don’t remember where those vacuum pumps were installed on the Airbus…
Stupid me, it was for the toilet flush system
Dan wrote:
Stupid me, it was for the toilet flush system
Hahaha, excatly that’s what a vacuum system is for!
Seriously – yes ! Give me a red X over the screen any day over a slowly dying vac AI. Red X – go on stb instruments and carry on. Annoying, for sure, but not the end of the world. Especially if you have a secondary AHRS source, such as a Stratus. If you you have dual G5 installation (or a G1000) hit the reversion mode button and off you go.
FWIW we are about to get rid of the vacuum system in our entire club fleet and replacing it with dual G5s. It’s a slow(ish0 process due to budgetary constraints, but I think in two years there won’t be a single vac pump left in the fleet. Good riddance.
172driver wrote:
Seriously – yes ! Give me a red X over the screen any day over a slowly dying vac AI.
I’ll second that. A few years ago, on the first minute of an IR revalidation flight, my vacuum AI suddenly started showing ~10° left bank in straight and level flight. Everything else was OK – that is, it did indicate pitch and bank changes, but with that 10° error. I told the examiner I could just continue in partial panel mode, but he balked at that and made me return visually.
The maintenance company that repaired the AI told me there was nothing wrong with it except some dirt in the bearings.
In my case with an Stec 60-2 and Stec 901 GPSS, I can turn off both the G5 and pull the CB on the G500Txi and still fly a GPS route and approach, but not the vertical.
