KI-256 replacement options

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peter-h

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peter-h
Mine has gone on the blink again, and this is a unit supplied as OH from Mid-Continent ~ 200hrs ago, and it was about 2 degrees off the vertical alignment from the start. I had no choice but to install it, obviously. I would have expected something better of a US$3000 overhaul/exchange from a supposedly reputable US avionics repair shop.

A new KI-256 is about US$11000. My previous one lasted ~ 800hrs.

It erects eventually but takes ~ 10 mins.

AFAIK my options are

1) G500 with the GAD43 (~US$70000 plus here in the UK, and a truly massive job.....)

2) KVG-350 remote gyro (~US$25000 and rarely if ever used in GA, and needs 110V AC :) )

3) Aspen EFD-1000 (not certified yet as a KI-256 replacement, but they have been talking about it for years, and anyway the built-in battery doesn't last anywhere near long enough so I would need a remotely mounted battery)

4) Some other "horizon" product? I have never seen one.

5) KFD-840 perhaps (a BIG bet on Honeywell not dropping it)

The hassle with the KI-256 is that if I do an exchange on it ($3000) I will get a unit whose pitch/roll nulls will be shifted, and the KC225 computer will need re-adjusting. In the UK there is only one avionics shop which can do it, and last time I did it it was an all-day job plus a hotel stay. I now have all the manuals plus the $1400 bus extender (bought 50/50 with another pilot who is in the same "hole"
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) plus a mains powered vac pump unit so now I can get it done locally, but it is still a hassle.

Incidentally, regarding the above vacuum pump, can one simply connect its suction pipe to the OUTLET of the existing engine-driven vac pump? With the engine stationary, it should work; I can't see why the external vac pump cannot simply suck via the engine vac pump. The reason for this is that the back of the KI-256 is not easy to get to in-situ.

Any tips appreciated
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Maybe I should keep a spare. Is anybody selling a good KI-256 060-0017-01 ?
 
I fight the KI256 weekly, it's a very lousy product. Mid Continent does most of our work except most KI256 units. When you get caught in the warranty loop it's hard to get out. I just sent one from a Jetprop to Air Dallas Instruments for repair and it seems to be working well. "It's one big crap shoot" I would give MC another shot for any warranty consideration. The best fix is the Garmin 500 with GAD43. I really want this with the EDM930 engine gauges in my Malibu.

Regards, Kevin
 
One more thing. I have a good used -00 unit on the shelf. I don't know what the difference is.

Regards, Kevin
 
Duncan Aviation www.duncanaviation.aero 402-475-2611 will OH these for $1600 +parts..usually ends up being $1800. I have OH 2 of these with them now (seperate Bonanzas)and they do a great job...I actually just dropped another one off yesterday along with a roll servo

Waiting for the Aspen Evolution upgrade that is not gyro dependent for AP.


I think Duncan has a sat shop somewhere in Europe...otherwise just pull it out and send it in (with some A&P help if needed)
 
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Many thanks for the input guys. I am contacting Duncan too.

Mid Cont are hiding behind their warranty on this one, even though it was never right to start with. They want $3.8k for an OH exchange unit.

I see the service manual selling for about $200 on Ebay. That is quite a lot for a SM so there must be a lot of "field repair" going on ;) A bit like the KS27xC servos ;) - I have the maintenance manuals for those but they were awfully hard to find...

What amazes me is that nobody has introduced a LCD instrument which is a drop-in replacement for the KI-256. It would be easy to design and make. Instead, everybody is working on solutions which cost 5 digits just to install. The Aspen product will probably be the least bad solution but even that costs a lot to install if you want to get the full functionality / avionics integration.

Currently I am trying to buy one of these, because it's obvious that I need a spare. In theory, I should be able to get the mechanics fixed for under $1k here in the UK, by a small shop doing just mechanical instruments. All the Honeywell dealers charge $3k+ for an OH exchange and about $6k for an OH unit. The list price for a new one is an amazing $24k
 
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Aspen (and many others) have the technology already on the shelf, to make a KI-256 lookalike, very easily.

It's purely a marketing decision.

The funny thing is that I've just seen some schematics and they are dated 1980. Speaking of cash cows... at $11k-$24k, how many $millions and millions have Bendix/Honeywell made out of this little cash cow?
 
I emailed Aerolab last week. No reply as yet.

Am I right in that the EA-100 interfaces the EFD-1000 to a KFC225, so the backup horizon (which must be a vacuum unit, unless one gets into the separate backup battery stuff) can just be a "cheap" Sigma-Tek one?

Everybody I have spoken to speaks of bad experiences with Mid-Continent - except one company which sells a lot of their stuff. I will avoid them, however, because they should have never sent out the one I now have.
 
peter-h said:
Am I right in that the EA-100 interfaces the EFD-1000 to a KFC225, so the backup horizon (which must be a vacuum unit, unless one gets into the separate backup battery stuff) can just be a "cheap" Sigma-Tek one?
Click to expand...

That's my understanding: the EA-100 should allow for total replacement of the KI-256. I couldn't find much information on the unit, but hopefully it will be released soon. I don't like the thought of maintaining the King HSI and AI system indefinitely.
 
IMHO, seeing the price jump to $24k, Honeywell are saying to people they don't want to make it anymore, so from now on everybody will only be overhauling their old ones, which (exchange) is about $3k.
 
Just as an update: I have bought (outright) an overhauled KI-256 from Castleberry Instruments - a really good and helpful company.

This was a Mod 11 unit, with the buffered pitch/roll outputs.

It replaced another Mod 11 unit (the ex Mid Continent overhauled one which lasted only ~ 200hrs and which, I am now advised by another overhauler, has duff bearings).

It went in today. NO KFC-225 autopilot adjustments were needed (these are a major hassle, needing the $1400 bus extender, etc).

(except the trivial in-flight roll null, done from the front panel, to balance the left/right turn bank angles).

The flight test also went perfectly. I have never had a KI-256 which runs so straight.

The instrument was spot on, out of the box.

So anybody replacing a KI-256, go for Mod 11, and I can certainly recommend this company.
 
Thanks for the tout, Peter.

Looks like they shipped pretty quickly, as well.

You should come visit their operation. Then you'd be in Texas, and we could buy you a beer.
 
Aspen's EA-100 is finally released, about a week after I gave up and canceled my order. I wound up getting my KI-256 overhauled by Bob Bramble and am picking up the plane Monday.
 
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