We're actively shopping for a Twin Cessna, maybe a 340. One possible candidate has the Cessna 400A autopilot, as the plane is a '74. Should I run away from anything equipped with this autopilot, or expect frequent trips to Autopilots Central, or one trip with an open checkbook and have a like-new autopilot thereafter, or......??
Also, what are update options, if the 400A proves to be undependable?
Thanks
GS

I had a 400B in my 340 and it worked very well. It was hooked up to a GTN and I believe the altitude capture on a G500/600 now works with a GAD43e. Having said this, the only support in town is AP central. If you have an issue they will get it right but may cost you some change.

If you wan to upgrade, the Stec 55 is a good option. My 2 cents is that if the 400A is working, leave it. Changing the AP is a 20-30K proposition. I don't know the difference with the B, but I suspect it's minimal.

I had a 414 with the 400A AP. It's a great AP and easy to fix. Autopilots Central can help you with any issues. The 400A will work as well if not better than a STEC. It will fly an ILS perfectly. I would have zero issues buying a plane with the 400A.

Take it to AP, get an IRAN and it should be good to go with minimal maintenance for a long time. You can maintain a legacy autopilot forever for the cost to upgrade.

There are other auto pilot shops out there than autopilots central. Griffin avionics at Hyannis Mass takes care if all the box repairs we can't handle in house.

I had a 400B (not sure of the difference between a 400A and B) in my T210 and an 800B IFCS (flight director version) in my 421 and each worked well. Yes, there were minor issues, but nothing too bad and certainly nothing worth the cost to replace them.

Robert

The 400A and the 400B system only share three alpha-numeric characters................They are completely different A/P systems. With that said, the 400B is preferable over the 400A as more parts are becoming obsolete on the A. Both are excellent autopilots when working properly, and maintenance on either is straightforward. The B didn't appear until 1975 or so. If you select an aircraft with a B, the absence of the Cessna/ARC flight director is a positive. The flight director mode selector is problematic...............

An autopilot guy once told me that ARC finally got it figured out when they built the 400. (Don't remember if he specified A or B) Said it's a good A/P. Then, not a deal breaker.

Thanks for each of your comments, as it really helps to hear from those with hands on experience, both operators & maintenance. No decision yet, but this info clears the way to own a 400A without concern & let other factors drive the decision.
Gary S

When I was shopping for a 400 series Cessna, I personally avoided any airplane with the original Cessna autopilot.

The plane finally purchased has a King KFC 225, which is digital, and attitude based.

Second choice would be the STEC 55X.

I hear that the King KFC 200 is a good autopilot too.

Just recently sold a 340A with the 400B. (As others have said, I have no experience with the 400A) After an IRAN on the 400B we had around 650 relatively* trouble free hours with it paired with a GTN750 and an Aspen PFD until we decided to upgrade from the C340.

* I say relatively as we had some issues with moisture getting into the control box (outside the pressure vessel) which caused a few slight problems with the pitch control on AP but those were corrected for under 2-3 AMU's.

That being said, if I had to do it again and you plan on keeping this aircraft for the long haul, I'd try to acquire something with an STEC55X with alt capture giving you the benefit of more fluid motion, as opposed to the clunky 400B G/S intercept and slight tracking over correction like it just left the bar at closing time.

Just my opinion, hope it helps.

Mike Busch wrote some very nice "400 autopilot" comments about Bob Weber @ Mayday Avionics in Grand Rapids, MI:

"Bob Weber at Mayday Avionics is one of the best autopilot technicians in the country, and probably THE best when it comes to older autopilots. I have a Jurassic ARC 400B in my Cessna 310 chock full of mid-70s-vintage technology, and Bob’s the only person I trust to turn to when it gets cranky. I’ve never actually met Bob in person (I hope to remedy that soon), but he’s one of my maintenance heroes nonetheless. (And I’m a hard marker.)"

Doug,
I have met Bob and he's a great guy and knows autopilots. He diagnosed my A/P issue immediately and gave me excellent advice on the repairs.

Dave

Bob has worked on a 400 autopilot on a customer's 421. He knows the autopilot better than the back of his hand. He found a $35 switch was bad and repaired the autopilot after the previous owner spent thousands at another local shop trying to repair the same squawk.

However, lately, I've had a multiple quality control issues with their work (some Bobs, some other guys in the shop). Another friend had the same results with his twin Cessna. I believe they may be getting too big for their structure, concentrating on larger aircraft too much, or just getting bored after being in business so many years.

Jason