The Warrior is getting some avionics work where the KLN94 will connect to a CDI display and the S-Tec 20. The KLN94 replaced an old Apollo GPS.
This YouTube has a good briefing on a set up for the Garmin 155/300xl where the annunciator panel plays an important situational awareness role when the panel has an old style DG and CDI with no auto slew or PFD fly-by message alerts, or GPS mode displays.
Looking for annunciator candidates I found
https://avionicssource.com/product-category/avionics/annunciators/
For those flying non glass DG without auto slew, messaging, etc, and with, what are in effect early generation, GNSS set ups, have you invested in an annunciator or just have the old NAV source GPS/VOR switch?
With GPS approaches you live or die by the FMA’s but…… oooooo that cost !
I had A KLN89B and like the KLN94 the unit drops the light to ground when active. I had some annunciation lights fitted and supplied the power from the aircraft lighting bus.
The light units I used are EAO series 41 ( also used on SOCATA aircraft ).
These light units also have light/ switch opinions that I used for the NAV / GPS switching and APP arm.
Well apparently I will need a KI209A or KI208A to speak to the KLN94, which can be found for around 1 AMU, $2.5k new. Presumably the old KI208 might be worth a few hundred bucks.
Looking somewhat painful for a unit which won’t be used in anger.
I don’t think you need a KI208 for a legal KLN94 installation. What you do need is a CDI/HSI presentation in the primary field of view, but you want that anyway for normal flying, I would think.
Usually one doesn’t look at it, however, if one has an MFD.
The type of annunciator lamps is not specified. You can use all kinds. TSO is not needed; the Socata (EAO/Swisstac) ones are not TSOd.
…or at the risk of another G5 vs GI275 thread replacing the DG with one of these units might be the best upgrade.
Then figure out whether the GNC255 NAV COM, the KLN94 and the S-tec20 can all speak to it.
I don’t think the G5 would give any compatibility issues but G5 installation is not quite as simple as it might seem.
That having been said from a pilot perspective I think it is an excellent unit.
@A_and_C thank you
I think this may give the GI275 an advantage as it fits the normal legacy panel, but then may require a database to be maintained.
The KLN94 should work with any CDI/HSI with a resolver. The annunciator, switch panel, and relay can be via an integrated system or built with lamps and switches. A relay will be needed if you are going to share an existing CDI with a Nav receiver, although with a newer Nav unit that supports the ARINC 429 a G5 or GI275 are reasonable options. Peter and I collaborated on KLN94 AFMS FAA approval where we added the ability to use an out of date database.
@NCYankee thank you, apparently it can’t work with a plain KI209, it needs a KI209A. RGV told me why, but it went over my head, something about how the KI209 processes the signals.
It also apparently can’t work with a GI275, but yes it works with a G5, so some surgery on the plastic trim of the panel. The G5 HSI is a couple of AMUs cheaper than a GI275, and has a built in annunciator. The GI275 needs a WAAS GPS apparently.
Forgot to ask about roll steering, but as the Warrior is on a budget am guessing you manually make the track change as you approach the waypoint using the OBS?
Not sure if the KLN94 auto-slews on the G5 but will investigate. @Peter can advise if his Sandel auto slews with the KLN94. On a KI209A you have to update the CDI for each track.
The KI209 will have to be blanked off and the indicator seems to be worth around one AMU second hand.
An important milestone in the life of the Warrior occurred today: the wing spar passed the eddy current NDT inspection!! On the factored FAA formula it is a very low time Warrior (around 1,000 factored hours), but good news that this AD, even though not applicable at the moment, is behind it.
As discussed here roll steering is not possible with a KLN94 (because all current roll steering converters, whether standalone or integral to something, require the ARINC429 roll angle commands, which the KLN94 doesn’t output), but as that thread shows you don’t really need roll steering for most “normal” flight.
If you have an EHSI (compared to a mechanical HSI) then the course pointer will flip around to the next track and the aircraft will turn by itself. Yes the SN3500 does this perfectly with the KLN94. If the G5 doesn’t turn its course pointer like that, that would be pretty useless.
I did some digging. The KI209 has a internal converter and is for used mainly with VOR type radios, like the KX155, that have composite nav output. The KI209A has an internal relay that bypasses the converter and connects the Left+ Right+ output of the GPS directly to the needle coil. This allows it to be used with most GPSs. So basically the KI209 is just for VOR/LOC indication; no good for a GPS track deviation bar.
