400a autopilot to Century Non-slaved HSI
 

I'm getting a bunch of avionics finally swapped out
- Century non-slaved HSI
- dual KX155 w/GS one to a KI-209 and the other to the new (to me) Century HSI
- KLN 90B w/annunciator
- King DME

taking out old nav/comms and Loran, but keeping the ADF (still works:)

Here's the set-up....the guy doing the work says he is having problems figuring out the 400a to the HSI. Apparently it gets its info from the old DG (then there is a little know on the control unit where you set the heading you want it to fly). So he tells me today that he wants to put the DG back into the plane just to have it hooked up to the autopilot. My main concerns: 1) I would like to have it hooked up to the HSI like the other new stuff, 2) would like to have that empty hole avail for when I can finally afford to add an engine monitor, and 3) if I am going to have something redundant, it would not be dg (already have a magnetic compass for that redundancy...would put another gauge there, like electric AI).

Here's the question....
- anyway to hook-up the 400a to the Century HSI so it will get it's heading info from there, or even better to get the direction from the heading bug on the HSI ??
- anyway to just replace the 400a control unit (with that little heading knob) with a newer 400 (or something compatible with all the other stuff like servos, etc) ??
- any other good alternatives ??

-Robert
rmorris@agsi.us
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Medical marijuana

Robert
Let me know the Skymaster you have, if the a/p IS a 400A. and what is the p/n of the HSI installed. Then I can help you.

Cheers
Pete

inventory
 

1968 T337C 337-0775, N2475S
a/p is a Navomatic 400, not sure now about the 'a'. Thought it was until you questioned it :) ...it's the one with the little heading knob on the a/p control unit itself, so you control what heading you want it to fly by turning that little knob, and supposedly it then correlates to the heading on the DG...attached is a pic of the control unit
The Century HSI is:
NSD-360 HSI S#1191E
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JUSTIN BIEBER FAN

Robert
Your Avionics Guy is correct. The heading information comes from the DG on the Navomatic 400 system and you cannot hook up a external DG to this system.
The control unit is part of the 400 Navomatic system.

Pete

OK, you need to work on how you deliver bad news :)

Seriously, any thoughts (Pete or others) on any other options. Go out and upgrading to an STEC 50 is not really an option for me (just had to pay to replace the rear engine, and now for getting all this avioics work done, not to mention a TON of other items, all since last September).
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Avandia Heart Attack

Robert
There is no way around this, I went thru the same thing and could not find an answer, the DG has to go back into the system, so we installed it in the right panel and piped it up to the vac.
At least you have a spare DI and you will still have to remember to reset it.

Cheers
Pete

Hmmmm. I have a slaved HSI. My autopilot is the 400, not A. It has a switch, for heading or approach. Approach works off the HSI, and heading works off the old DG. I remember flying it, tracking a VOR, and it will track a VOR. We were several miles away, so it wandered a bit, but we definitely can track a VOR, off the HSI. I think it will also fly the glidescope.

Yes Larry you can do it that way, however the heading referance will still have to come from the old DG as this is the only compatible unit for this autopilot.
Nav can be coupled up normally with VOR/ILS coupling but but the heading reference will be from the DG.

Pete

yes, forgot that part. The heading DG is still in place, the old vacuum one, and when the autopilot is in "heading" mode, it is driven by the old DG.
Incidentally, I fly it in heading mode 99% of the time.

Larry, if you are in Heading or Nav mode the DG still provides Heading as this is required for crosswind correction whilst on a radial or a Loc approach.
Unfortunately this is one of the older autopilots that require the whole system to be there to make it work correctly, and with upgrading the autopilot there is no way around this problem.

Cheers
Pete

servo or upgrade
 

UPDATE:
He went ahead and put in the old DG, so it's still wired to the Navomatic 400...but since he tells me there is a bad servo, he didn't hook-up the KLN90B or KX155 to the ap (ie nav inputs).

So I'm looking at two options:
1) Source a servo for the Navomatic 400 and ask him to complete the install - which still means that I have to have my old DG for heading input, not my newly installed Century HSI
2) Find a cost effective upgrade to the Navomatic 400 instead of just replacing the servo on thois one.

All comments welcome (either here or email me at rmorris@agsi.us)

Specifically -- sources for #1? suggestions (and please keep the 'go buy a new STEC 60' to yourself, looking for other alternatives that come from experienced owners/pilots/mechanics)...maybe a way to upgrade to a newer Navomatic with minimal part changes and labor? Of course, sources for any parts suggested for #2 as well.

Thanks,
Robert
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Airsoft pellet gun

Robert
Try Jason King at Airwich Avionics www.airwich.com he will be able to help you with the parts you need 316 942 88721

Pete

Pete.
How come my autopilot works with the KCS 55 then. Is this only a problem with Century hsi's ?
Sunnysky

Yours is a 400A and there is a adapter (KA51/57) which allows this system to be used.
The old 400 uses a different heading signal and AC system and of course HSI systems were very few in the Nav-O-Matic 400 days.

Pete

Just testing Pete. Thought you would know !!
Sunnysky.