Help with S-TEC 50 A/P

[Michael Ware]

Okay, one of the club's planes has an autopilot installled, that I have
never been able to make operate. Get up to level cruise, turn it on and
wait. All I get is a blinking 'TRIM UP' light, never get the 'READY' light.
Is it hosed, or am I missing a step?

--
Hello, my name is Mike, and I am an airplane addict...

[Dan Luke]

"Michael Ware" wrote:

> Okay, one of the club's planes has an autopilot installled, that I have
> never been able to make operate. Get up to level cruise, turn it on and
> wait. All I get is a blinking 'TRIM UP' light, never get the 'READY'
> light.
> Is it hosed, or am I missing a step?

Switch it to "Test" first. It will do its test sequence, ending with a
bunch of lights on, including the "Trim Up" light, IIRC.

Then, switch it to "On." The green "Rdy" light will illuminate. If you now
press the "On" button, the "Push Hdg/Sts"activates in wing leveler mode.
Press the "Push Hdg/Sts" button and the autopilot will steer to the course
set on the heading bug. Once the bank axis is active, the altitude hold
function is available.

--
Dan
C172RG at BFM

[john smith]

In article >,
"Dan Luke" > wrote:

> "Michael Ware" wrote:
>
> > Okay, one of the club's planes has an autopilot installled, that I have
> > never been able to make operate. Get up to level cruise, turn it on and
> > wait. All I get is a blinking 'TRIM UP' light, never get the 'READY'
> > light.
> > Is it hosed, or am I missing a step?
>
> Switch it to "Test" first. It will do its test sequence, ending with a
> bunch of lights on, including the "Trim Up" light, IIRC.
>
> Then, switch it to "On." The green "Rdy" light will illuminate. If you now
> press the "On" button, the "Push Hdg/Sts"activates in wing leveler mode.
> Press the "Push Hdg/Sts" button and the autopilot will steer to the course
> set on the heading bug. Once the bank axis is active, the altitude hold
> function is available.

There is a delay of one or two minutes before the altitude hold will
engage. Be patient.

[Michael Ware]

"Dan Luke" > wrote in message
...
>
> "Michael Ware" wrote:
>
> > Okay, one of the club's planes has an autopilot installled, that I have
> > never been able to make operate. Get up to level cruise, turn it on and
> > wait. All I get is a blinking 'TRIM UP' light, never get the 'READY'
> > light.
> > Is it hosed, or am I missing a step?
>
> Switch it to "Test" first. It will do its test sequence, ending with a
> bunch of lights on, including the "Trim Up" light, IIRC.
>
> Then, switch it to "On." The green "Rdy" light will illuminate. If you
now
> press the "On" button, the "Push Hdg/Sts"activates in wing leveler mode.
> Press the "Push Hdg/Sts" button and the autopilot will steer to the course
> set on the heading bug. Once the bank axis is active, the altitude hold
> function is available.
>
> --
> Dan
> C172RG at BFM
>
Thanks, Dan. I love the 296, BTW. Very useful.

[Michael Ware]

"john smith" > wrote in message
...
> In article >,
> "Dan Luke" > wrote:
>
> > "Michael Ware" wrote:
> >
> > > Okay, one of the club's planes has an autopilot installled, that I
have
> > > never been able to make operate. Get up to level cruise, turn it on
and
> > > wait. All I get is a blinking 'TRIM UP' light, never get the 'READY'
> > > light.
> > > Is it hosed, or am I missing a step?
> >
> > Switch it to "Test" first. It will do its test sequence, ending with a
> > bunch of lights on, including the "Trim Up" light, IIRC.
> >
> > Then, switch it to "On." The green "Rdy" light will illuminate. If you
now
> > press the "On" button, the "Push Hdg/Sts"activates in wing leveler mode.
> > Press the "Push Hdg/Sts" button and the autopilot will steer to the
course
> > set on the heading bug. Once the bank axis is active, the altitude hold
> > function is available.
>
> There is a delay of one or two minutes before the altitude hold will
> engage. Be patient.

OK thanks guys. Had it out visiting relatives last weekend. Not much fun
openening/folding sectionals with one hand.

Mike

[Ron Rosenfeld]

On Fri, 02 Jun 2006 23:33:40 GMT, "Michael Ware" >
wrote:

>Okay, one of the club's planes has an autopilot installled, that I have
>never been able to make operate. Get up to level cruise, turn it on and
>wait. All I get is a blinking 'TRIM UP' light, never get the 'READY' light.
>Is it hosed, or am I missing a step?

The a/c should have an AFM supplement explaining how to test the a/p during
PREFLIGHT. If you cannot locate it, you can always download the POH from
http://www.s-tec.com/pdf/sys4050poh.PDF

Once you have read the manual, and gone through the pre-flight test
procedure, you should be able to figure out whether the problem lies in the
autopilot, or the operator.

Under normal circumstances, the 'READY' light should have been on prior to
takeoff.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Roger]

On Fri, 2 Jun 2006 19:12:29 -0500, "Dan Luke"
> wrote:

>
>"Michael Ware" wrote:
>
>> Okay, one of the club's planes has an autopilot installled, that I have
>> never been able to make operate. Get up to level cruise, turn it on and
>> wait. All I get is a blinking 'TRIM UP' light, never get the 'READY'
>> light.
>> Is it hosed, or am I missing a step?
>
>Switch it to "Test" first. It will do its test sequence, ending with a
>bunch of lights on, including the "Trim Up" light, IIRC.
>
>Then, switch it to "On." The green "Rdy" light will illuminate. If you now
>press the "On" button, the "Push Hdg/Sts"activates in wing leveler mode.
>Press the "Push Hdg/Sts" button and the autopilot will steer to the course
>set on the heading bug. Once the bank axis is active, the altitude hold
>function is available.

Mine must be broke. I can turn on alt hold with out the heading being
active. It doesn't care which sequence I use other than it takes a
minute or so before the altitude hold works after turning the AP on.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

[Dan Luke]

"Roger" wrote:
>> Once the bank axis is active, the altitude hold
>> function is available.
>
> Mine must be broke. I can turn on alt hold with out the heading being
> active. It doesn't care which sequence I use other than it takes a
> minute or so before the altitude hold works after turning the AP on.

When you press the "On/Off" button, the roll axis is active (you can control
the turn rate by twisting the knob). The altitude hold function is then
available.

--
Dan
C172RG at BFM

[Thomas Borchert]

Michael,

the manual is available for download at S-TEC's site.

There are two on switches on this autopilot. One is on the control unit
itself, it activates basic operation in wing leveller mode, indicated
by "STB" for STABILIZE. However, there should be a 3-position AP master
switch somewhere on the panel. That switch has OFF/ON/TEST as
positions. You need to put it through test mode first, preferably on
the ground. After testing, leave that switch in ON (with the ready
light on), otherwise you'll have to do the test again. The test
includes engagement of the clutches, which can be irritating when done
in flight.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Roger,

> I can turn on alt hold with out the heading being
> active.
>

That's by design. If HDG mode is off, but you have the autopilot
switched on, STB will be showing in the display, which stands for
STABILIZE, otherwise known as wing leveling. Of course, you can hold
ALT in that mode.

--
Thomas Borchert (EDDH)

[john smith]

In article >,
Thomas Borchert > wrote:

> You need to put it through test mode first, preferably on
> the ground. After testing, leave that switch in ON (with the ready
> light on), otherwise you'll have to do the test again.

I always wondered about the logic of that, given that the POH
specifically states, "AUTOPILOT OFF FOR TAKEOFF".

[Michael Ware]

"john smith" > wrote in message
...
> In article >,
> Thomas Borchert > wrote:
>
> > You need to put it through test mode first, preferably on
> > the ground. After testing, leave that switch in ON (with the ready
> > light on), otherwise you'll have to do the test again.
>
> I always wondered about the logic of that, given that the POH
> specifically states, "AUTOPILOT OFF FOR TAKEOFF".

Yeah, that's one reason I assumed you could just turn it on, wait a few
minutes and it would be ready to go. I think they are talking about the
Sperry 'Navomatic' autopilots. Sounds like something Ronco would sell.

[Ron Rosenfeld]

On Tue, 06 Jun 2006 15:50:48 GMT, john smith > wrote:

>In article >,
> Thomas Borchert > wrote:
>
>> You need to put it through test mode first, preferably on
>> the ground. After testing, leave that switch in ON (with the ready
>> light on), otherwise you'll have to do the test again.
>
>I always wondered about the logic of that, given that the POH
>specifically states, "AUTOPILOT OFF FOR TAKEOFF".

Not sure about the POH as I don't see that in the POH for the autopilot.
Maybe it's in the AFMS for the autopilot?

In any event, the A/P Master switch can be left on, even with the A/P
switch off, as is the case when I take off.

Also, if the A/P Master is turned off in flight, then it needs to be placed
in the 'Test' position in flight and allowed to run through its self-test
until the 'Ready' light comes on, before it can again be used in flight.
This is also mentioned in the POH for the a/p.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Thomas Borchert]

John,

> I always wondered about the logic of that, given that the POH
> specifically states, "AUTOPILOT OFF FOR TAKEOFF".
>

That's referring to the other OFF switch. Also, other manufacturer's
autopilots are different in that regard.

BTW, always know all the way to switch off the autopilot in case it
goes berserk.

--
Thomas Borchert (EDDH)

[Ben Jackson]

On 2006-06-03, john smith > wrote:
>
> There is a delay of one or two minutes before the altitude hold will
> engage. Be patient.

And in my experience, you don't want to be trying to get the altitude
hold to engage as soon as it possibly will. There seems to be a small
window where it will engage but immediately command a slight nose up/down
rather than just holding altitude. Passengers don't like it!

--
Ben Jackson
>
http://www.ben.com/