KLN94 improving flight deck annunciator, and KLN94 driving a G5, and KLN94 approved for GPS approaches?

Roll steering.

It is a more accurate way of getting an autopilot to make turns, and it enables complex turns to be carried out.

I find it hard to believe that the KLN94 is not approved for IFR ( NP ) approaches. It is a slide in replacement for the KLN89b that with the correct software level is IFR approved.

Has someone not taken care to read the SB that would have been published when the software upgrade happened.

I might be wrong but why would King build an upgraded slide in replacement box with LESS capability than the old box ?

The problem with this kind of assertion (when my TB20 was new, 2002, and going on G-reg, the CAA inspector said the KLN94 is VFR-only, and demanded that the IFR modes are disabled) is that somebody needs to dig through some old manuals, find some precedent, and nobody is going to have the time to do that and then convince the installer.

The KLN94 was a standard fit in so many fully IFR certified planes of that era e.g. a C182 came with that King stack.

I’ve done some digging around on this.

Of course a KLN94 is IFR approved, except for RNAV1 SIDs and STARs.

The issue, as I suspected, is the AFMS, and the local certification authority.

This post probably summarises the situation in the properly anally retarded manner. You need an AFMS for the GPS and the AFMS needs to permit whatever mode e.g. enroute IFR or GPS approaches.

Whether the candidate GPS appears in the G5 IM is not relevant. You need some way to get that AFMS, and it needs to be approved by the certification authority.

The simplest route is via a factory TC, so if you buy a plane which was ever equipped with a KLN94 ex-factory, just get hold of a copy of somebody’s POH from that era (roughly 2000-2004) and copy the AFMS, hole-punch it, and insert it into yours. And this will work with most planes, because most certified planes are IFR approved airframes, and an awful lot of them came with a KLN94 at some point. And if done in the US, GPS approaches would have been in the AFMS!

Except Socata is not in the US and they managed to pull some wool over their customers eyes in the US. Their AFMS excluded GPS approaches. I did an AFMS for my KLN94 to make approaches legal which – being N-reg – was done as a Field Approval. But I did that only because I have a “public profile” in GA via running a forum, which picked up a lot of good people from other forums. There are even people out there who don’t like the fact I have a website with trip writeups. And if somebody wanted to stab me in the back give me hassle, they could use this – because everybody can hear on the radio what you are doing. But a Joe Nobody doesn’t need to care. You just install a KLN94, think of it as VFR-only, and fly it. Prob90, the installer never even knew the IFR features can be disabled. They can’t be disabled on any GNS, etc. They can be re-enabled in a few minutes.

How you would do with with an EASA-reg plane, which never had a KLN94 ex-factory, for which a mod was never applied for (as far as you can find), then it is an EASA Major Mod and loads of €€€. Unless it can be done under one of the concessions (CS-STAN?) about which I know nothing. You still need the AFMS though… A specimen one is in the back of the KLN94 IM.

You can get an EASA AFMS approved for RNAV 5 and NPA via a Form 32 (Minor change to AFM). A Part 21J with appropriate privileges can approve this directly with no Agency involvement.
If you want RNAV-1/PRNAV and LPV, EASA require this to be done via an STC.

Peter wrote:

I did an AFMS for my KLN94 to make approaches legal which – being N-reg – was done as a Field Approval.

Pretty much all IFR approvals prior to the GNS WAAS series were accomplished by field approvals. So the IM provides a sample AFMS which the installer needed to get submitted for approval via the field approval process. Only later with the GNS series, did the practice come along where doing a STC with an AML where the AFMS is part of the STC and merely needs to be printed out and added to the POH. Even in the STC case, one could modify the AFMS and request a field approval. The STC process was much simpler for the installer.

You can get an EASA AFMS approved for RNAV 5 and NPA via a Form 32 (Minor change to AFM). A Part 21J with appropriate privileges can approve this directly with no Agency involvement.

What would be the typical fee for this?

When I was trying to get my KLN94 approach approved, various shops were engaged to do it, within a £500 budget which they all accepted, and all failed to do it. It was NCyankee who eventually helped me to get it done.

I understand this will need a magnetometer.

You do need a fluxgate magnetometer to create a slaved compass system. The main challenge there tends to be the hacking of the hole in the wing, constructing the inspection cover for it, etc. Quite a bit of metalwork. Unless it can go in the tail.

When an avionics upgrade occurs in Europe, do the removed, working units, find their way back to the USA second hand market?

Probably… however, Americans tend to be a bit suspicious of European stuff, with many having got their fingers burnt, and there is no comeback.

I monitor a US for-sale group on FB and it astonishes me what absolute total junk people are selling on there. Or old used current-model boxes at just say 10% below the new price. Well, trying to sell. Unlike with Ebay, there is no way to view “completed listings” so you can’t tell what stuff actually sold for.