Autopilot use during approach

I've moved up to a new plane that includes an S-Tec 50 autopilot. It has
several very capable modes ranging from Wings Leveler, Track a Heading bug,
Follow NAV input, Hold a set Altitude, and approach mode which tracks NAV
input more closely.

What do the regs say about the permissible use of an autopilot after the
enroute portion of a flight that is being conducted under instrument flight
rules? To what extent is it permissible to use the autopilot during an
approach? For example, after the controller says "radar vectors for..."
through DH?

Thanks!

Every airplane flight manual/POH has an autopilot supplement
that answers those questions. The autopilot must be
configured to begin and complete the approach early in the
sequence so that it can arm and capture the loc and gs
properly.
Typically you can stay coupled to 50-100 feet AGL on a GS
and to 50 feet below MDA on a non-precision approach.


"Ron Gordon" wrote in message
t...
| I've moved up to a new plane that includes an S-Tec 50
autopilot. It has
| several very capable modes ranging from Wings Leveler,
Track a Heading bug,
| Follow NAV input, Hold a set Altitude, and approach mode
which tracks NAV
| input more closely.
|
| What do the regs say about the permissible use of an
autopilot after the
| enroute portion of a flight that is being conducted under
instrument flight
| rules? To what extent is it permissible to use the
autopilot during an
| approach? For example, after the controller says "radar
vectors for..."
| through DH?
|
| Thanks!
|
|

"Ron Gordon" wrote:

I've moved up to a new plane that includes an S-Tec 50 autopilot. It has
several very capable modes ranging from Wings Leveler, Track a Heading bug,
Follow NAV input, Hold a set Altitude, and approach mode which tracks NAV
input more closely.

What do the regs say about the permissible use of an autopilot after the
enroute portion of a flight that is being conducted under instrument flight
rules?

Nothing, at least for Part 91 operations; might be different for 35 or 121, I
don't know.

To what extent is it permissible to use the autopilot during an approach?
For example, after the controller says "radar vectors for..." through DH?


I use my S-Tec 50 in approaches all the time, but usually not in the final
segment of an ILS. The 50 is not a top-of-the-line autopilot; I flatter
myself that I can do it better.

--
Dan
C172RG at BFM

Ron Gordon writes:

I've moved up to a new plane that includes an S-Tec 50 autopilot. It has
several very capable modes ranging from Wings Leveler, Track a Heading bug,
Follow NAV input, Hold a set Altitude, and approach mode which tracks NAV
input more closely.

What do the regs say about the permissible use of an autopilot after the
enroute portion of a flight that is being conducted under instrument flight
rules? To what extent is it permissible to use the autopilot during an
approach? For example, after the controller says "radar vectors for..."
through DH?

Anything you can legally fly by hand can also be flown by the autopilot, since
you remain in command and can take over at any time; using autopilot is like
using trim in that case. However, you can't use the autopilot to fly
something you could not legally fly by hand unless both you and the aircraft
are certificated to do so. As long as you are flying an approach that you can
legally fly by hand, whether or not you actually use the autopilot to fly it
is purely your choice.

In contrast, there are situations in which flying by hand is not allowed and
only flying by autopilot is permitted (or only flying by hand with special
assistance, such as EFVS, is permitted), such as landings that are below the
minimums for any type of hand-flown instrument approach (Cat IIIc autolands).
These require that both pilot and aircraft (and instruments) be approved for
the automation in question.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Ron,

As Jim says, there's advice on that in the POH. Keep in mind that the
S-TEC 50 does not intercept/capture radials or localizers. You have to
get the plane onto the localizer (which can of course be done with the
AP in heading mode). Only after that you can engage the approach mode.
Main difference between approach and nav is the sensitivity. With the
S-TEC 50, you will still have to manage the altitude profile yourself.

I have seen vastly different accuracy on different installations in
different aircraft with the S-TEC 50. On our Tobago, it can be used
well on approaches down to 200 feet.

--
Thomas Borchert (EDDH)

Jim,

so that it can arm and capture the loc and gs
properly.


The S-TEC 50 doesn't do that.

--
Thomas Borchert (EDDH)

On Fri, 13 Apr 2007 13:01:32 +0200, Thomas Borchert
wrote:

Ron,


I have seen vastly different accuracy on different installations in
different aircraft with the S-TEC 50. On our Tobago, it can be used
well on approaches down to 200 feet.

In my Mooney, I will occasionally allow my STEC50 to fly an approach, if
there is absolutely no turbulence and little change in the winds during
descent. Sometimes it even gets to DH/MDA still on the centerline! But
it's not unusual for it to get 1/2 to 3/4 scale off course.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On Fri, 13 Apr 2007 04:08:29 +0200, Mxsmanic
wrote:


Anything you can legally fly by hand can also be flown by the autopilot, since
you remain in command and can take over at any time; using autopilot is like
using trim in that case. However, you can't use the autopilot to fly
something you could not legally fly by hand unless both you and the aircraft
are certificated to do so. As long as you are flying an approach that you can
legally fly by hand, whether or not you actually use the autopilot to fly it
is purely your choice.

In the Cirrus the autopilot manual (STEC 55X) did not permit operation
below 200 feet or when full flaps were deployed. Clearly a case where
you could legally fly by hand but not with the autopilot.

Ron,

But
it's not unusual for it to get 1/2 to 3/4 scale off course.


I know. A friend of mine has similar issues in a BN-2.

--
Thomas Borchert (EDDH)

Mxsmanic wrote:

Anything you can legally fly by hand can also be flown by the autopilot, since
SNIP

That is a patently false and dangerous statement.