Piper AUTOCONTROL I User manual

}
PIPER
‘
ustomer
erwces
Aurocommol.
I
&
II
AL
TIMATIC
I
&
11
Service
Manual
_
PIPER
AIRCRAFT
CORPORATION
753
79s
-

PIPER
AIRCRAFT CORPORATION
LOCK
HAVEN,
PENNSYLVANIA
THIS
SERVICE MANUAL
ISSUED
JUNE
1961
LICENSE NOTICE
A
9
These
components
manufactured under
one or
more
of
the
following
Mitchell
patents
and/or
licenses:
181,158.
321,465;
326,089;
562,
289;
554,448;
548,099;
2536749.
2039021;
2853671;
and
other
pending
patents
.
MITCHELL
INDUSTRIES
Mineral
Wells,
Texas
Printed
in
U.S
.A
.
mi-l

If
""""
PIPER
ALTIMATIC SERVICE
MANUAL
This
Service
Manual
(P/N
753
798)
has
been
compiled
to
include
the
following
publications:
Piper
Altimatic
Service
Manual
(P/N
753
616),
Electronic
Letters
(EL-Letters),
Electronics
Service
Letters
(SE-Letters),
Omni-Localizer
Coupler
Service
Manual
(P/N
753
691)
and
Piper
AutoControl
Service
Manual
(P/N
751
532).
Any
of
the
above
mentioned
publications
released
prior
to
May
1969
should
be
considered
obsolete.
fma
)
Added:
5/1/69
,
.
iii/iv

flux
,/""’“’\
PIPER
ALTIMATIC
SERVICE MANUAL
REVISIONS ISSUED
Current,
Permanent
and
Temporary
Revisions
to
this AutoControl
I
and
II
and AltiMatic
I
and
II
Service
Manual
compiled
May
1969
are as
follows:
753
798
(PR710920)
Permanent
Revision
Dated
September
20,
1971
753
798
(PR721020)
Permanent
Revision
Dated
October
20,
1972
v/vi

f“,
1
.
PIPER
ALTIMATIC SERVICE MANUAL
FOREWORD
This Service Manual
is
provided
as a
guide
for
installing,
servicing
and
maintaining
the
Piper
AltiMatic Pilot
and Omni-Localizer
Coupler
.
The
information
presented
in
this manual has
been
divided into
three
sections:
Theory
of
Operation,
Installation
and
Servicing.
An
index
is
located
in
the
front
of
the
manual
to
provide
a
quick
reference.
The
information
compiled
in
this
manual
will
be
kept
current
by
revisions
distributed
to
the
manual
owner
through
their
local
Piper
Dealer
or
Distributor
.
R
EVISI
ON
There
will
be
two
(2)
types
of
revisions
used
to
keep
this
manual
current.
The
material
compiled
in
these
revisions
will
consist
of
information
necessary
to
maintain
the
present
equipment,
therefore,
it
is
imperative
that this
material
be
inserted
in
the
service
manual
at
the
time
it
is
received.
I
.
Temporary
Revision
This
type
revision
willbe distributed
at
any
timeit is
necessary
to
forward
Technical
Servicing
Information
to
the field.
The
temporary
revision
will
usually
consist
of
one or
two,
pages
which
may
be
inserted
in
the
front
of
the
manual.
These
revisions
will
include
deletions
and
additions
of
material
pertinent
to
dif—
ferent
paragraphs
of
the
service
manual,
therefore,
when
the
temporary
revision
is
received,
review
the
manual
and
mark
the
affected
paragraph
with
the
code
date
of
the
latest
revision
for
a
ready
reference.
11
.
Permanent
Revision
This
type
revision
will
supersede
allprevious
temporary
revisions
.
These
revisions
will
be
of
complete
page
replacement
and
shall
be
inserted
in
the
ser-
vice
manual
as
per
the instructions
given
below
.
I
.
Replace
the
obsolete
pages
with
revised
pages
of
the
same
page
number.
2
.
Insert
pages
with
page
numbers
followed
by
a
small
arabic
letter
in
direct
sequence
with
the
same
common
page
numbers
.
3.
Insert
pages
with
page
numbers
followed
bya
capital
arabic
letter
in
direct
sequence
with
the
same
common
page
number but
after
any
pages
with
the
same
common
page
number
followed
by
a
small
arabic
letter
.
Added:
5/1/69
vii/viii

f )
f )

flax
II
III
IV
Added:
5/1/69
TABLE
OF
CONTENTS
I
,
PARTI
~
ALTIMATIC
seams
MANUAL
THEORY OF
OPERATION
..............
INSTALLATION
AND
ADJUSTMENTS
.........
TROUBLESHOOTING
.................
APPENDIX
|
.....................
PARTII
OMNI-LOCALIZER
COUPLER
DESCRIPTION
.
.
.
I ..................
.
SPECIFICATIONS
.
.................
MAINTENANCE
..................
ADJUSTMENT
PROCEDURE
.............
DARE
APO-I
RADIO
ADAPTER
FOR
RADIO
COUPLER
USE
................
.I-I
Z-I
3-1
A-I
.ZO
ix/x

ff)

/
fmx
PIPER
ALTIMATIC
SERVICE
MANUAL
INDEX
Section
1
THEORY
OF
OPERATION
.
l
-
1.
General
1-3.
Description
.
l
—
5.
Theory
-
General
1—6.
Theory-Ron;
1—7.
Theory—Pitch
II
INSTALLATION
AND
ADJUSTMENTS.
2—1.
General
. ..
2-2.
Removal
and
Replacement
of
Altimatic
COmponents
.
2-3.
Instruments
.
2—4.
Amplifiers
2—5.
Console
. .
2-5A.
Resetting
the
1X225
Altitude
Selector
When
System
is
in
the
Aircraft.
2-6.
Installing
Pitch
Control
Knob
2-7.
Removing
Roll
Servo
2-8.
Removing
Pitch
Servo
.
2—8a.
Removal
of
Pitch
Servo
(#1X312C)
2-8b.
Installation
of
Pitch
Servo
(#1X312C)
2-9.
Timing
Roll
Servo
Unit.
2—10.
Timing
Pitch
Servo
Unit
2—ll.
Roll Servo
Friction
Disc
Adjustment
2—12.
Pitch
Servo
Over-
Ride
Adjustment
2-13.
Backlash
Adjustment
of
RollServo
2-14.
Pitch
Servo
Chain
Adjustment
.
2—15.
Adjustments
.
. . .
.
2-16.
General
. .
2—17.
Selectivity
and
Quiescence
Current
Adjustment
2—18.
General
.
2—19.
Roll
Adjustments
.
2-20.
Bench
Checking
Pitch
Amplifier
.
2—20A.
Resetting
the
1X225
Altitude
Selector
on
the
Bench
.
2—21.
Test
Flight
.
2—22.
Altitude
Selector
Adapter
(Part
No.1A236).
REVISED:
9/20/71
Page
mI-hl-hl—II—II—n
OOO\O\O\O\O\
9a
9b
10
11
12a
12a
13
13
13
14
15
15
16
16,
16
16
18
19
19a
20
21
Xi

INDEX
(cont. )
Section
111
TROUBLESHOOTING
.
3—
1.
General
3—2.
Equipment
Required
for
Troubleshooting
.
Appendix
I
.
LIST
OF
ILLUSTRATIONS
l
I—nNI—n
Altimatic
Console
Altimatic
System
. .
Directional
Gyro
with
Amplifier.
Artificial
Horizon
with
Amplifier
Altimatic
Console
.
Pitch
Control
(Manual
Position)
Pitch
Control
(Automatic Position)
.
Roll
Servo
Pitch
Servo
PA-
24
and
PA—
24—
250
.
.
Pitch
Servo
(1X312C)
Installation,
PA—
24
and
PA-
30
Pitch
Servo
Adjustments
.
Piper
Test
Box
A
Testing
Servo
Motors
.
Wiring
Diagram
.
| | |
0 3
N
llII
\ l \ l O \ U 1
1
1
2
2
2
2-4
2
2
2
2
2.
w o a o a
}
I
I , \ | " , I ’
w w a é ' o o
LIST
OF
TABLES
Climb
and
Descent
Speeds
Troubleshooting
Chart
REVISED:
9/20/71

[fix
(“a
m“,
,,
Added:
5/1/69
PART I
ALTIMATIC
\
xiii

O
O

PIPER
ALTIMATIC SERVICE MANUAL
r“
SECTION
I
THEORY OF
OPERATION
I
-
I
.
GENERAL.
1—2.
This
manual
contains
service
and
maintenance
information
necessary
to
maintain
and
Operate
the
Piper
Altimatic
Pilot.
The
maintenance
instructions
given
for
each
system
includes
troubleshooting,
testing
and
corrective
main-
tenance.
(It
is
recommended
that
only
qualified
personnel-perform
the
operation
described
herein
.)
1_-3.
DESCRIPTION.
The
Piper
Altimatic
Pilot
is
a
high quality, light weight,
four
control AutoPilot
designed specifically
for
the
Piper
single
engine
Comanche
and the
twin
engine
Apache
and
Aztec.
The
purpose
of
the Altimatic
is
to
hold
the aircraft
on
a
selected
course
and altitude
setting.
The
Piper
Altimatic
consists
of
eight
principle
units:
The
Directional
and
Gyro
Horizon
with
transistorized
Amplifiers,
the Automatic Altitude
Selector,
Pitch
and
Roll
Servos,
and
the
Console
unit
which
houses
the
controls
for
the
Altimatic.
The
Amplifiers
are
mounted
on
the
backs
of
the
Directional
and
Horizon
Gyros,
each
amplifier
has
a
control
protruding through
the
instrument
panel
to
the
right
of
the
gyro
instrument
it
affects.
The
Roll
and
Pitch
Servo
units
are
a
motor
and
gear
device
which
are
attached
to
the
aileron
and
stabilator
controls
of
the aircraft.
On
the
Apache
and
Aztec
the
R011
Servo
unit
is
attached
to
the
control
wheel shaft
of
the
co—pilot's
wheel,
while
on
the
Comanche
the
unit
is
attached
to
the
pilot's
control.
The
Pitch
Servo
unit
on
the
Apache
and
Aztec
is
attached
to
the
right
portion
of
the
control
column
under
the
instrument
panel.
On
the
Comanche
the
Pitch
Servo
is
located
under
the
removable
portion
of
the
floorboard
to
the left
of
the
nose
wheel
housing.
F
Both
the
Directional
Gyro
and
the
Horizon
Gyro
have
internal
modifications
to
include
electronicsensing
elements
which
are
used
to
send
signals
to
the
amplifiers.
The
Console which
contains
the
controls
for
the
Altimatic
is
posi—
tioned
in
the
lower
left
corner
of
the
instrument
panel
on
the
Apache
and
Aztec,
while
on
the
Comanche
it
is-
located
below
the
radio
stack. This
Console
(See
figure
l-l)
serves
several
purposes:
(I)
It
engages
the
Servo
units to
the
con-
trols
by
meshing
a
set
of
gears
and
(2)
at
the
same
time,
operates
an
electric
switch
in
the
Servos,
energizing
the
electronic
components
of
the
Altimatic.
REVISED:
3/1/62
1

PIPER
ALTIMATIC
SERVICE
MANUAL
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Dim
Switch
No. 6. Down
Effort
Light
No.
2.
Calibration Knob
No.
4.
Pitch
Engage
Knob
No.
7
.
Altitude
Selector
Knob
No.
5.
Up
Effort
Light
Figure
1-1.
Altimatic
Console
(3)
It
also
contains
two
("up"
and
”down")
effort
lights
which
indicates
the
direc-
tion
the
pilot
will
have
to
trim
the aircraft
before
fully
engaging
the Pitch
Control
knob,
the
effort
lights
will
also indicate
an
out-of—trim condition
,
which
is
cor—
rected
by
trimming
the
aircraft
up
or
down
depending
on
which
light
is
Operating.
These
two
effort
lights
and
the
Console
dial
lights
are
connected
to
a
rheostat
on
the
Console,
so that
their
intensity
can
be
lowered
for
night
flying.
The
Console
also
contains
the
Automatic
Altitude
Control
which makes
it
possible
for
the
pilot
to
select
the
desired
Altitude
while
in
flight
or
before
the
take-off is
made
if
the
pilot
so
desires.
The
Altimatic
requires
.04
ampere
of
current
for
standby
operation
and
2
amperes
during
servo
Operation.
A
5
ampere
circuit
breaker
is
installed
to
protect
electrical
components.
No
warm—up
period
is
necessary
as
the
tran-
sistors
in
the
amplifiers
are
operational
immediately
upon
activation.
There
is
only
10
pounds
additional
weight
added
to
an
aircraft
already
equipped
with
the
Gyro
instruments.
REVISED:
3/1/62

PIPER
ALTIMATIC SERVICE MANUAL
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REVISED:
3/1/62

PIPER
ALTIMATIC SERVICE MANUAL
1—5.
THEORY-GENERAL.
To
understand the
Piper
Altimatic,
visualize
it as a
closed circuit radio
that
is tuned to
a
particular
frequency
(10
Meg)
and
whiCh
has the
ability
to
re-
tune
itself
when
displaced
from this
frequency.
In
this
case
it
is
a
radio
in
an
airplane
with a
set
of
flight
instrument
sen-
sors
in
the
radio
circuit. These sensors
are
in
tune
(on
frequency)
when the
airplane
is
in
level
flight
and
on
heading.
If
the
airplane
is
disturbed
from
this
level
flight
condition,
the
sensors
will
signal
the
amplifier,
which
will
send
voltage
to
the
appropriate
servo.
In
effect,
the
radio
circuit
re—tunes
itself
with
the
aerodynamic
effect
of
the
ailerons
or
elevator
as
the
need
may
be.
Two
components
of
any
tuned
circuit
are
INDUCTANCE
and
CAPACITANCE.
To
produce
a
desired
frequency,
the correct
relation
must
exist
between
these
two
factors.
An
increase
in
inductance
will
require
a
decrease
in
capacitance
in
order
to
maintain
a
frequency
and
of
course
the
reverse
is
true,
i.e.
a
decrease
in
inductance
will
require
an
increase
in
capacitance
in
order
to
maintain
a
desired
frequency.
This
is
the
basic
electronic
principle
used
in
the
Altimatic
for
sensing
flight
attitude
changes
.
1-6.
THEORY-ROLL
SECTION
A.
INDUCTANCE:
The
pitch
and
roll
circuits
are
two
separate
systems,
however,
they
are
identical
electrically
and
the
same
theory applies
to
both.
Figure
1-3
typifies
one
of
these
systems
in
its
simpliest
form.
INDUCTANCE CAPACITANCE
AMPLIFIER
CONTROL
SERVO
’
SURFACE
0—7
CD-
I,2
813
Figure
1—3.
4
REVISED:
3/1/62
f )

PIPER
ALTIMATIC SERVICE MANUAL
The
inductance
portion
of
the
frequency,
Shown
as a
circle
in
figure
1-3,
is
in
the
roll coil of
the artificial
horizon.
This
coil is mounted
in
the
top
rear
of
the
horizon
case.
The coil
protrudes
into
the
case
and
is
in
close
proximity
to
a set
of
vanes
(as
shown
in
Figure
1—4)
that
are
attached to the
gyro
gimbal
assembly.
ALUMINUM
VANE
INDUCTANCE
COIL
The
vanes are
made
of two
different
materials,
the
one
on
the
right
of
the
coil,
as
Viewed
from
the
rear,
is
made
of
aluminum
and
the
one
to
the
left
is
made
of
ferris
iron.
The
vanes,
being
attached
to
the
gimbal,
will
remainlevel
with
the
horizon,
while
the
roll
coil,
being
attached
to
the
case,
moves
about
the
longitudinal
axis
of
the
airplane
and
thus
changes
the relative
position
of
the
coil
to
the
Vanes.
A
change
in
the
inductance
is
accomplished
by
this
movement
as
indicated
in
Figure
1
-5
.
DECREASED
INDUCTANCE INCREASED
INDUCTANCE
.
LEFT
BANK
RIGHT
BANK
VIEWED
FROM
REAR
OF
INSTRUMENT
Figure
1-5.
REVISED:
3/1/62

PIPER
ALTIMATIC SERVICE MANUAL
One of the
outstanding
features of
the Altimatic
is
that
the
sensing
accom-
plished
by
this
method
requires
no contact
between
the
sensors
and
imposes
no
additional loads
on
the
delicately
balanced
gyro
mechanism.
This
system
also
produces
a
smooth
change
in
signal
and
because
of
the
amplification
method
and
type
of
servos
used,
will
result
in
a
desirably
smooth
control movement
of
the
proper
amount for
the
displacement.
This control movement
can
be
shOWn
on a
graph.
The horizontal
com—
ponent
being
the
bank
displacement
and
the
vertical
component
being
the
wheel
movement
in
degrees.
Figure
1-6
illustrates
these
responses.
_
5
r
m
mzo‘ummm
I — m r n z t s
rIght
response
-
left
res
onse
25
--
p
curve
‘
curve
mmm
5 0 6 3 1 1 1 0
FIGURE
4
40
3'0
ab
I5
A)
Is
2'0
30
40
'
RIGHT
\-
DEG
OF
BANK
-
LEFT
Figure
1-6.
This
curve
is
held
to
precise
limits
by factory
adjustment
of
the
coil
and
vane
relationship.
Overhaul
of
the
instrument
and
adjustment
of
this
relation—
ship
should
not
be
attempted
without
the
Mitchell
Instrument
Test
Console
and
the
knowledge
of
its
use.
B.
CAPACITANCE:
The
necessary
capacitance
of
the
roll
circuit,
shown
in
Figure
1—3,
is
found
in
a
series
Of
variable
condensers.
These
variable
con—
densers
are
in
the
DC.
heading
sensor,
the
manual
trim
control,
roll
follow—
up,
and
leveling
condenser
in
the
amplifier.
While
their
design
and
appearance
may
vary
according
to
the
location
and
the
function
performed,
they
all have
the
common
effect
of
changing
the
capaci-
5a
~
ADDED:
3/1/62