Century 1 AP driven from the CDI?

[Sundancer]

Does the Century 1 autopilot with "VOR tracker" take it's direction from the CDI?

I ask because I'm shopping older airplanes (Grummans, Pipers) and seeing a LOT of Century 1 APs installed. I understand (I think) the Century 1 won't track the heading bug, and the course has to be "captured" pretty close before it will track, but I can live with that.

Tracking a GPS course via the CDI is good enough for now.

 

[asicer]

Does the Century 1 autopilot with "VOR tracker" take it's direction from the CDI?

Pretty much. As I recall, the input is just left/right deviation. I suppose theoretically it can come straight from the NAV source without going through a CDI.

 

[Duke3478]

It's Really more of a wing-leveler and an aileron trim than an AP, but once you get good at using it, it's handy.

I don't fly VORs but I can put it on course, trim out the speed and altitude, and fly hands/feet free with a little tweaking. You get used to little adjustments on the trim knob, and you can even dial in turns.

It's definitely better than nothing, but you won't be using it to fly approaches. It will level the wings, but in sustained turbulence it gets a little chasy.

 

[Sundancer]

It's Really more of a wing-leveler and an aileron trim than an AP, but once you get good at using it, it's handy.

I don't fly VORs but I can put it on course, trim out the speed and altitude, and fly hands/feet free with a little tweaking. You get used to little adjustments on the trim knob, and you can even dial in turns.

It's definitely better than nothing, but you won't be using it to fly approaches. It will level the wings, but in sustained turbulence it gets a little chasy.

Really looking to confirm it'll follow the CDI needle - the dcumenttion in the VOR Tracker enabled version indicates it will, once you get it closely aligned. If it's tracking the CDI, then I can use it when the GPS is driving the CDI, whicj is what I want. What I'm reading is that's probably the case. Would like to know for sure, or if a mod is necessary to get that function.'

 

[SixPapaCharlie]

Yes, It follows the CDI needle but only about as well as a 5 hour student pilot.
Its primary function is to hold the wings level for about 30 seconds while you put salsa on your burrito.

I had one in my Grumman for 4 years and maybe turned it on 5 times mostly just to show people that it wasn't all that great.

 

[pburger]

Does the Century 1 autopilot with "VOR tracker" take it's direction from the CDI?

I ask because I'm shopping older airplanes (Grummans, Pipers) and seeing a LOT of Century 1 APs installed. I understand (I think) the Century 1 won't track the heading bug, and the course has to be "captured" pretty close before it will track, but I can live with that.

Tracking a GPS course via the CDI is good enough for now.

I had a Century I (Piper Autoflite II) in my Arrow when I bought it in 1995. It had the NavTracker option. It tracked VOR courses very well once established. I used the chit out of it. I would always file airways so that I could use it to track the VORs. When I had my first IFR GPS installed (Garmin GNC-300XL) back in 2005, they installed a switch to select which CDI the A/P would be coupled to -- NAV1 or GPS. It accepts the left/right signals that get sent to the CDI. It will track a localizer, too. It won't do GPSS, and there's no vertical component (it's a single-axis autopilot). If you turn off the Nav tracking, it's a wing leveler -- sometimes that's all you want or need. I loved my Century I. It served me well until 2018 when I updated to the TruTrak. Good luck to you!

 

[farangutan]

We labeled our Century I AP inop in our Grumman in case an examiner asks us to use it. About 1/3 of the time it tracks perfectly. All the other times I can't get it to work.

 

[Rex Kwan Do]

I have a century I and it works well. The manual spells out it is approved for use to the FAF although since it is looking at left/right deviation it doesn’t make procedure turns or anything like that very well. I have it configured to accept either signal from the KI-209 CDI (VOR/ILS) or the GNX 375 navigator.

it also has a “heading hold” mode (right knob pulled out) where it’ll try and keep the heading or you can twist that knob right or left and it will bank in that direction with a full throw twist to the limit commanding a standard rate turn.

i find that the easiest way to make a significant heading change.

It’s rate based and basic tech so you can’t compare to a modern auto-pilot but it absolutely will reduce pilot work load. I notice it will drift from time to time about 1/3 of a NM along the route but the left hand knob is a “trim” that you can use to aid in wind correction.
I find mine is absolutely fine for cruise use in IFR/VFR and even on a straight in if you’re looking to lighten your workload.

keep in mind there are only a couple places that work on them and an overhaul can run around $3k on the head unit.

 

[Sundancer]

I have a century I and it works well. The manual spells out it is approved for use to the FAF although since it is looking at left/right deviation it doesn’t make procedure turns or anything like that very well. I have it configured to accept either signal from the KI-209 CDI (VOR/ILS) or the GNX 375 navigator.

it also has a “heading hold” mode (right knob pulled out) where it’ll try and keep the heading or you can twist that knob right or left and it will bank in that direction with a full throw twist to the limit commanding a standard rate turn.

i find that the easiest way to make a significant heading change.

It’s rate based and basic tech so you can’t compare to a modern auto-pilot but it absolutely will reduce pilot work load. I notice it will drift from time to time about 1/3 of a NM along the route but the left hand knob is a “trim” that you can use to aid in wind correction.
I find mine is absolutely fine for cruise use in IFR/VFR and even on a straight in if you’re looking to lighten your workload.

keep in mind there are only a couple places that work on them and an overhaul can run around $3k on the head unit.

Thank you, good info - it supports what I've been reading; so many older Grummans and Pipers have a version of the old Century APs - usually the advertisements say "Century AP" - or just "AP". A panel picture can sometimes narrow it down to the model, depending on picture quality. I can now discern between a Century 1 "tracker" and wing leveler from a panel photo - sometimes. You can, I believe, still buy a new Century 1, something like $9K.

 

[asicer]

it also has a “heading hold” mode (right knob pulled out) where it’ll try and keep the heading

That's not "heading hold". That's "wings level" mode. Only if you are lucky will wings-level coincide with a kept heading.

 

[Rex Kwan Do]

That's not "heading hold". That's "wings level" mode. Only if you are lucky will wings-level coincide with a kept heading.

Lol, I know it seems that way sometimes but page 7 of the manual says:

“The Autopilot, when properly trimmed, will seek to hold a constant heading (no turning). If the aircraft consistently flies wing low, it indicates that the rudder is not properly trimmed and rudder trim is needed in the direction of the low wing.”

The auto pilot is referencing the gyro (it’s also your turn coordinator) to maintain heading. It is definitely far from perfect.

 

[asicer]

Lol, I know it seems that way sometimes but page 7 of the manual says:

“The Autopilot, when properly trimmed, will seek to hold a constant heading (no turning). If the aircraft consistently flies wing low, it indicates that the rudder is not properly trimmed and rudder trim is needed in the direction of the low wing.”

Yeesh! Can it be any more obvious that the marketing department wrote the manual?