Can the G900 kit fly a “virtual ILS” to any point on the ground? I think it can (it’s a copy of the g1000). Only g3x, gtn650/750 and g430/530(w) can’t, in the Garmin world.
I think pretty much all of the uncertified efis can show jeppesen ifr charts like an ipad with JeppFD can, but I don’t think they can load an ifr approach procedure point by point for your autopilot to follow. Perhaps the 900x is an exception given is a direct derivation from a certified gps/nav/com. To be honest I’m not sure what’s the price difference between a 900x and a (used-) g1000, but if the 900x is super rare there must be a reason…
(The G900 does not have the G1000’s GFC700 digital autopilot)
What AP does it have? What is a “digital” AP? The KFC225 does it all in software too.
“(The G900 does not have the G1000’s GFC700 digital autopilot)”.
Not correct. Like the g1000 can or cannot have the gfc700 (sometimes they just come with the kap140), the 900x can or cannot have the gfc7x (see the Lancair Evolution).
Afaik, the “archaic” rate-based autopilots that are still in large use in the certified world (like kap140 or stec50), left the experimentals world long time ago for the more advanced attitude-based non-certified autopilots (e.g. Trutrak), in theory equivalent to the expensive certified gfc700 and dfc90/100.
AFAIK the G900 has no autopilot but can be connected to the typical A/Ps used in kitplanes
EDIT: Valerio is right, The G900X can be retrofit with the " GF7X"autopilot (which I did not know). Seems to be the uncertified version of the GFC700
But it looks like the "GFC7X is only available for the Lancair Evolution! (From an article in FLYING Magazine, but from 2012)
Peter,
of course you know that better – but when we speak about “digital autopilots” we mostly think about the newer highly integrated systems like the DFC90/GFC700, no? But i am aware that even a KAP 140/150 or a KFC225 work digitally.
How would you put that?
Once you get the control loop implemented in software, it’s a “digital” autopilot, IMHO.
Otherwise it’s marketing-speak, because – as any physicist will say – the universe is analog 
BTW are the KAP140/150 done in software? I don’t know. I have the MMs for the KFC225 but not the older ones. The huge problems (mostly servo burnouts) of the KFC225 are seemingly due to the computer getting itself confused and outputting an aggressive waveform on top of the correct control voltage (so the aircraft continues to fly OK while the servos are frying) while the earlier computers, whose servos have the same vulnerabilities since the 1970s, don’t have the issue.
But it looks like the "GFC7X is only available for the Lancair Evolution!
That is interesting – Garmin must have seen some volume there… unless it is purely a GFC700 re-labelling exercise (which would be logical).
I had a chance to discuss the UK permit IFR project with the project lead (Peter Penguilly) a while back and he has also written regular updates in the LAA magazine. This is my take on what he had to say (not his words verbatim).
Unlike in the US experimental system (where the builder has a lot more leeway), the LAA generally adheres to the design codes for ICAO C of A aircraft e.g. CS-23 but can adopt a lighter touch approach to the standard of proof required, commensurate with the level of risk. That evidence can come from different sources. The easy route is to insist on certified equipment or normal ICAO certified aircraft practice but that delivers no savings over fully certified aircraft. The difficult route involves gathering all the evidence through trials but that is impractically expensive. Between these two lies the possibility of tapping into the experience gained elsewhere (mostly the US).
In the US, there is a lot of experience of non-TSO’ed flight instruments, which achieve similar reliability to that of TSO’ed kit (an experimental solid state AHARS unit doesn’t have to try too hard to match the reliability of a certified vacuum pump and mechanical gyro AI). The LAA is combining that experience with a requirement for a dissimilar back-up attitude source and a 10 hour VFR-only proofing period before IMC flight to make the case that equivalent safety is maintained.
However, the situation with IFR navigation is completely different, because the FAA requires TSO’ed navigation equipment for IFR flight (ref: FAA Aeronautical Information Manual 1-1-18 d.1. and 1-1-18 e.3.). That means that all the (official) experience from the US experimental world has been gained with certified navigation kit and the LAA is going down the same route. Thus, a significantly cheaper non-certified GPS navigator is not likely anytime soon in the UK permit IFR world.
(Edit: CS-23 was CS-21)
Many thanks for that info, Raiz.
the FAA requires TSO’ed navigation equipment for IFR flight
How does that map onto the G900 being non-certified? I must be missing something. AIUI, to fly IFR in the USA you need a certified GPS but you don’t need a certified MFD/PFD/EHSI/etc and presumably the LAA will be the same.
