Automatic Navigation Computer ASN-7
i
f
suromane MEKEOWN, P, J.’
COMPUTER |
jf FORD INSTRUMENT COMPANY
/ DIVISION OF SPERRY RAND CORPORATION
fopyeiaht 1960 by ford destiument Company | 4
FORD INSTRUMENT
presents
The ASN-7 is « self-contaiics t
by Ford Instrument Compsis
of flight. This brochure is aise
what-it is, how it operates. oou. |
pilot, but to management tnd desig
facturéés, ground control zenters. ond the ‘So ais Som
Experts in the field of aerial mudution have si
approaches the yilot’s idzu! hh aid
Contenis
THE NEW ASN-7 iN ERIEF
AND ITS ADVANTAGES.
COMPONENTS iN. THE COCKEH
REMOTELY LOCATED COM
FLYING THE ASN-7Z....
STORING AN ALTERNATE PESTINATIC
THE ASN-7 IN FLIGHT
INPUTS AND OUTPUTS... I
SIZES, WEIGHTS .AND RANGES
ACCURACY... eee
US ABILITY, VERSATILITY, RELIABILITY
CHECKABIIT? AND: SERVICEABILITY
AGCESSORIES..........
tHE ASN-T- COMPARED
KBOUT FORD. LUNSTRUMENT
The ASN‘7, in brief
A dead reckoning computer
that continuously displays
course and distance
and present position
>>
Va
=e o
in the pilof’s cockpit are the
ASN-7 Indicator, (Course and Distance,}
and the ASN-7 Control,
The ASN-7 Automatic Navigation Computer is an outgrowth of Ford
Instrument’s ASN-6, a widely used present position computer. The
ASN-7 is a miniaturized computer which not only provides present
position, but also shows the pilot the direction he should fly, the ground
track he is flying, and the distance to his destination—_no matter how his
heading may change while in flight. This computer can be adapted to
telemetering equipment and used in many special applications (such as
traffic control). It has an auto-pilot output available as standard
equipment. The ASN-7 is operational and is being used extensively by
the U. S. Air Force in a wide variety of aircraft.
and its advantages for pilots and navigators
There are no pre-flight requirements.
Primary inputs are automatic and settings are simple.
An alternate destination can be stored within the system for
immediate use as desired.
No monitoring of the equipment is required.
No mental computation or manipulation of maps is necessary.
ASN-7 provides continuous information during flight.
* Accuracy of ASN-7 is guaranteed.
e The ASN-7 is completely fail-safe.
»
_
~¥
~V
-_
=
\y
"ODA Ocd
The pilot and the ASN:-7
—
COMPONENTS IN THE COCKPIT
INDICATOR =
7 ; Course, Ground Tra
MULTIPLE DISPLAYS. As Distance
many as three indicators can be
paralleled in the aircraft for mul- Heading Error
tiple displays—without any ad- to Avfopilos ““
ditional power requirements or
degradation in accuracy. Present Position
oufpul as needed
CONTROL Destination
coordinates
True Heading “6.
display as needed
Wind ond
Variation
information
COMPUTER CONTROL feeds wind, variation,
and destination data into the system. It displays
present position, wind speed and direction, variation,
and destination coordinates.
FLIGHT INDICATOR displays ground track, re-
quired course, heading error and distance to the
and destination coordinates. It is console mounted.
REQUIRED PANEL SPACE is only 5%” wide
x 4%” high for the computer control, and 314”
square for the indicator (actually a dodecagon).
This schematic shows the direction of flow of information
in the ASN-7. No special power system is required,
as the ASN-7 uses standard 28 v de and 115 v 400 cycle regulated ac.
Typical power consumption is 25 w de and 219 va ac in the normal run mode;
and 36 w and 236 va during insertion of information.
REMOTELY LOCATED COMPONENTS
COURSE AND
DISTANCE COMPUTES
COURSE AND DISTANCE
AMPLIFIER
Present
Position
5
Present & =
Position @ |= Bly ! aon
Ble 3 ( BS
) |g “MAGNETIC
| | VARIATION
COMPUTER
i Control
Signals *
PRESENT
POSITION
A Automatic AMPLIFIER
Variation
PRESENT
POSITION
COMPUTER
Flying the ASN-7Z
one N2 & \5.9-
mint ES ee
oF
OEST
N
- ”
. )
Me aTONE
Kps ¢ ,
WING APD wig olf
- t+
a he
SET MODE SELECTOR AT STANDBY. For this ftighi,
let us assume takeoff from Mitchell Air Force Base.
SET DISPLAY SELECTOR SWITCH FOR PRESENT
POSITION. Now we are ready to insert information.
.
STOSE
POOnj26 S|" ts
wikt SFO wad oe VAR *. Con
; —~3e WTe
SET DESTINATION POSITION WITH SLEW
SWITCHES. Assume destination is Wright-Patterson
Air Force Base, 39° 47’ North Latitude and 84° 04’
Longitude. La and Lo flags appear.
Let us suppose you are ready to take off in
an airplane equipped with the ASN-7 computer se
In the cockpit, all you will see will be the
Indicator and the Control shown in these pictures
All other units are remotely located. You
artae
5 Of) 2 4 lw z
0 7 OT) 2 e OW §35
wid BPO wis oe walt #ucor
—— tf + . : Welk app
",
SET PRESENT POSITION WITH SLEW SWITCHES.
Mitchell AFB's position is 40° 44’ North Latitude and
73° 36’ West Longitude.
INDICATOR shows a difference between present
position and destination of the previous flight.
ins: —sTdee
POOR? & §
WIN. SPO WIND. OIF
-— f+ - F +
SET STORAGE SWITCH TO INSERT POSITION.
This inserts destination information into computer.
RHUMB LINE COURSE AND DISTANCE FROM
MITCHELL AFB TO W-P AFB ARE AUTOMATI-
CALLY COMPUTED AND DISPLAYED, Pointer in-
dicates course; counter indicates distance ta be flown.
The LA and LO flags disappear.
know your present position and you know your
destination, so you are now ready to navigate with
the ASN-7. See how easy it becomes, by
operating the controls which are marked in
red on the illustrations on this page.
?
a dis sone
s —— i =— * .-
anfhet NED & GR Ww 7S a6
fuk? - => oF i=
a Fics Pos Presta
wnt SFO | WIND OIA var h200=
ne dg inek ae w Tf vy,
as
SET METEOROLOGICAL WIND DATA. In this case,
let us assume wind speed is 100 knots and wind is
from 245°.
SET SWITCH TO AUTOMATIC VARIATION. Unit
calculates magnetic variation for the computer and
automatically displays it,
FLYING WITH DOPPLER
THE ASN-7 1S COMPATIBLE with several currently
available Doppler radars. Use of radar of this type
brings ground speed and drift angle directly into the
ASN-7 system.
The same steps described in 1-6 are followed, except
that meteorological data need not be set in (see 3).
Instead, the wind speed counter is slewed back be-
low 0, and a flag reading GND. SPD. appears, in-
dicating that the system is in its GROUND SPEED
MODE—for operation with Doppler inputs. The wind
direction reading becomes irrelevant, The variation
switch is set to AUTOMATIC, as before.
“
Brtae
wiht a0 avip be VAR . IFeCOR
~ ft © = F : w Ee sv)
i, -
CHANGE DISPLAY SELECTOR SWITCH TO
DESTINATION. Now we are ready to insert destina-
tion information.
a ur LOnD
" RAES POS PRES POS
STORE
GARSPD nl 2 & 5 mW
wine Sho wes DR
o pe'y at ae
From the foregoing descriptions of the operation of the ASN-7, it is
evident that at no time is the pilot required to make any computation.
It merely is necessary for him to insert his present position and destina-
tion and wind information (unless he is flying with Doppler; then the
wind requirement is obviated). At any time during the flight, the dis-
play selector switch can be turned either to show present position or
destination.
On the following two pages, the insertion of an alternate destination is
described.
Storing an alternate destination
The ASN-7 computer has the capability of storing
an alternate destination, which simplifies navigation
when the primary destination is weathered in, or when
flights of more than 1000 miles are planned. Operation
of the storage feature is very simple, as shown above.
19
DEST
- ut Lous
nua?
pest NSD G7 |W 84 O6-
pest ES
*
STORE
Ta Fon
( OOn2 & 5 |W
and srg wo Be
Hers Doi matin
After the original destination has been inserted,
following the procedure on pages 8 and 9, the al-
ternate destination may be stored.
THROW STORAGE SWITCH TO STORAGE
POSITION. This is to prepare for insertion of the
alternate destination.
STORE
ic ee ee
wind. oP WIND tee wer
=*3.% - wit
SET ALTERNATE DESTINATION WITH SLEW
SWITCHES. We may have to fly on to Lockbourne
Air Force Base, 39° 50’ N. Lat., 82° 59 W. Long,
Storage flags appear in windows at left to indicate
Lat. and Long. display is not original destination.
These flags continue to show until the alternate des-
fination is inserted into the computer during a flight.
Of,
aa
ire
Fe
* aay iene
“
.
Rak FOG
gE oiy i:
wren od wan *. moe
| fan Wr
wine fo
t+
RETURN DISPLAY SELECTOR SWITCH TO
PRESENT POSITION. We are now ready for takeoff.
TURN MODE SELECTOR SWITCH FROM. STANDBY
TO RUN. This can be done at takeoff. It can alse be
done as we fly over departure checkpoint, which may
be noted either visually or by radio aids.
poumek siya 5
wieD 6PD WROD Os Was P. COR
= $9 - _ Ww 2-¢ Ue
oy
FLY THE AIRCRAFT TO LINE UP POINTER WITH
FIDUCIAL MARKER. This will put you on the required
ground track to destination. If at any time the pilot
desires to fly to the alternate destination, he can
insert this information by setting the storage switch to
INSERT position, At that time, the LA and LO flags
will disappear.
>»
Once a plane is airborne, the ASN-7 cam handle
navigation for any flight. On the next pages, a variety of
actual flight situations involving the ASN-7
are described,
1]
Any flight under 1000 miles will require only one setting, as in flight plan A, from
Mitchell AFB to Wright Patterson AFB. If the computed distance exceeds 1000
miles, a mask will cover the counter, indicating’ that the destination should be reset
to an intermediate point on the course.
If we are using meteorological wind data, it will be desirable to check our present
position when a fix becomes available. Let us assume that there has been a break
in the clouds, as in flight plan B, and we have been able to visually identify the
terrain below us. We throw the mode selector switch from RUN to P.P. RESET.
At this point, the display of PRESENT POSITION stops changing and. all changes
in present position will go into storage in the computer mechanism. The latitude
and longitude of the visual fix is inserted into the computer by slewing present position
with these switches. Once he has set in this fix, the pilot then returns the control to
the RUN position, and all changes in present position which have accumulated during
the interval required to insert the fix are now automatically inserted into the com-
puter. The present position counter of the display indicates a corrected present
position, and the course and distance indicator has been corrected accordingly.
Because of the STORAGE feature inherent in the ASN-7 computer, there is no
urgency about making the fix correction. The pilot may do this later at any reasonable
time, but until he does correct this position he will not get a correction of his course
and distance.
At any time, the pilot may deviate from the course indicated by the ASN-7. Let us
assume, for instance, that he wishes to deviate to avoid a storm, as in flight C.
The present position portion of the ASN-7 will continue to compute his present
position regardless of maneuver. When he has successfully flown around the storm,
he merely once again turns the aircraft in such a manner that the pointer is aligned
with the fiducial marker, and once again he is on a rhumb line course to his des-
tination, although this is obviously net the same course that he would have been on
had he not made the maneuver.
i
;
|
ovrwne
Peters Sire ee
eerie ieti is yi
00 em beseeriee
566 e4RAe eet et s+ 4 beers
+.
ceeneet®
Se ccovewnoerennt hn” :
edaeeeaeeorrrere® corer
Sait TRACK
CORRECHED a
FOSMION
DESFINATION. |
- a7. ANE
PASSES OVER (1
POINT X BY. PUSHING
INTERMEDIATE BOSHIC
CORRECTION: Ed 719
AY
‘x
!
1
\
ne bd
~~’
100 MILE
\ RADIUS
TAKE ©
DESTINATION K
OESTINA STRONGER WAND
THAN AT TAKE OFF
TAKE. OFF
4 . “
NEV? WIND DATA: ~~ ne DESTINATION
INStRTED
Alternate -
DESTINATION :
TAKE OFF =
SEF DESTINAWON
STORE
DESTINATION
ORIGINAL
DESTINATION
WEATHERED IN
BETERNA
CESRINATION. ¥
tNSEREED AS
DESTINAMEON Z
1S-STORED
When extreme terminal accuracy is desired, as on tactical missions, the INTER-
MEDIATE POSITION CORRECTION pushbutton on the ASN-7 control can be
used. This feature takes advantage of any known check point within 100 miles
of the actual target. The pilot inserts the check point as a “preliminary” destination
and stores the actual target as an “alternate” or secondary destination. After
take-off, the indicator guides the pilot toward the check point. As the plane nears
it, he arms the IP COR button by turning its knob counterclockwise. As the plane
passes over the check point the pilot pushes the button. The ASN-7 then corrects
the display of present position to that of the actual coordinates of the check point.
In sequence, the alternate destination (actual target) is automatically brought out
of storage and entered into the system; the course and distance to this destination
appear on the indicator. The change in present position accrued during this
cycling operation is automatically compensated for by the system. This entire
operation is in essence an automatic fix correction.
In flight plan E, let us assume that the pilot has received information of a change
in meteorological conditions, and has changed the wind information from its
previous value. This action results in a change in the computed ground track which
requires the pilot to turn the aircraft so the pointer is once again aligned with the
fiducial marker. The computer corrects for drift angle in such a way that, after
Present Position is corrected, the aircraft accomplishes its desired ground track to
destination.
In flight F, let us suppose that the plane has been told to land at its alternate des-
tination because its original destination is weathered in. In order to do this, the
pilot merely switches the storage switch from STORAGE to INSERT. The new
destination is automatically inserted into the computer which computes a new course
and distance to destination. Once the stored destination has been inserted into the
computer, it is possible to set another alternate destination into STORAGE. The
availability of the computer to accept a new destination is indicated by the disap-
pearance of the LA and LO flags. Therefore, the pilot may, at all times, have the
ASN-7 computing to one destination, with an alternate destination in STORAGE.
The pilot may easily navigate on flights longer than 1000 miles by’setting new alter-
nate destinations into the computer. Note in flight G that the procedures described
previously for alternate destinations are carried on over again until the final des-
tination has been reached.
CrSTINATIC
INSERTED
ASNT satisfies modern flight needs
Cockpit panel space is at a premium in modern aircraft. The pilot is confronted
with a vast array of dials, pointers, needles, markings, knobs, levers, buttons
and switches. This complex environment makes the pilot’s task very difficult.
Ford Instrument Company has designed the ASN-7 Navigation Computer to
make the pilot’s job easier and more foolproof, to eliminate mental and
physical tasks which have heretofore complicated flight, and to provide more
useful information with less effort and in less space.
On the following pages, you may see how the ASN-7 has satisfied these needs
in terms of current requirements.
INPUTS
HEADING
From Gyro Compass, such as types J-2, J-4, N-1
VELOCITY
From True Air Speed and Mach Number Computer
such as types A-1, A-2, C-1 and C-2
From Central Air Data Computer such as MG-1
From radar derived ground speed
MAGNETIC VARIATION
From Automatic Variation Computer
From manual setting
WIND SPEED AND WIND DIRECTION
From Doppler Radar
’ From other special equipment
From manual setting
PRESENT POSITION
From initial manual setting of latitude and longitude
From fixing information sources
DESTINATIONS
From manual sefting of latitude and longitude
FIX CORRECTION
From manual setting
From Tacan
From Omni DME
From celestial Data Computer
From radar devices
16
WIND. SPD WIND DIR
* e
- 5 - 5 +
\
MOT AS
ASNT satisfies modern flight needs
TOTAL wetter. Ft. 5- 410s WLIGHT EACLUDING SHOCK MOUNTS 46-7)'0 12s
~~ DIMENSIONS SWAY SPACE |
UNIT NUMBER | WEIGHT (TO NEAREST 64th) (PLUGS CONNECTED)
(LBS.) L w H L w H
a PRESENT POSITION COMPUTER CP-221 16.75 10-31/32 | 8-7/16 5 12-5/16 9-5/8 6-9/16
SHOCK MOUNT MT-1318 1.2 9-15/32 9-7/16 1-3/4 ; .
b | COURSE & DISTANCE COMPUTER CP-289A 18 10 5-27/32 | 5-21/32 12-3/16 7-1/16 7-1/8
SHOCK MOUNT MT-1736 1.0 9-3/4 6-7/8 1-1/2
c« | MAGNETIC VARIATION COMPUTER CP-290 445 7-3/32 411/32 3-7/16 a 5-5/16 415/15
SHOCK MOUNT MT-1744 0.65 §.25/432 4-7/8 1-1/2
d PRESENT POSITION AMPLIFIER AM-1069 8.75 8-1/64 8-55/64 5-7/64 9 9-57/64 6-1/4
SHOCK MOUNT MT-1909 1.0 8.35/64 6-1/8 1-3/4 :
e | COURSE AND DISTANCE AMPLIFIER AM-SIZA 8.0 9-11/32 | 8-55/64 5-7/64 10-9/16 | 9-57/64 | 6-27/64
SHOCK MOUNT MT-2012 og 8-17/32 7-3/8 1-1/2
£ | COMPUTER CONTROL UNIT * C-1317A 8.25 7-11/16 §-1/32 4-25/32 6-1/2 5-1/32 4-25/32
(CLEARANCE REQUIRED IN
REAR OF PANEL)
g INDICATOR * ID-390 2,63 6-27/64 3-1/8 DIAMETER 6-61/64 3-1/8 DIAMETER
(CLEARANCE REQUIRED IN
REAR OF PANEL)
“Dimensions of somtrot mad incicete: ds ear iehuce paral
moonting fengas tieegnege & fo- fecuired sane! spces?
ACCURACY
The ASN-7 is guaranteed to meet very high stand-
ards of accuracy. It far surpasses that delineated
in specification MIL-C-25528.
In operation, system accuracy can be increased
considerably by reducing wind errors. The pilot
can, on the basis of successive visual or radio fixes,
determine the “effective wind” and adjust the
wind inputs accordingly. And it is further possible
to incorporate devices whereby accurate wind in-
formation is derived by equipment completely self-
contained in the aircraft: for example, the Auto-
matic Fix Corrector (see page 22), or Doppler
radar, inertial components, etc.
COMPARISON OF GREAT CIRCLE AND RHUMB LINE DISTANCES
The shortest distance between two points on the
earth’s surface is, of course, a great circle arc passing
between those two points. A rhumb line course be-
tween the same two points is necessarily longer,
although it is more convenient to fly since a con-
stant heading is maintained. The decision as to
whether or not to use a rhumb line course depends
on whether the increase in distance is justified.
Under certain conditions, the rhumb line dis-
tance is very nearly equal to the great circle dis-
tance.’ These conditions may be summarized as
follows: First: Differences between the two is a
function of distance involved. For short distances,
such as the 1000 mile legs navigated by ASN-7, the
two paths are nearly coincident. Second: All merid-
ians are both great circles and rhumb lines. There-
fore, any rhumb line between points near the same
meridian is very nearly a great circle arc. Third: The
equator is both a great circle and a rhumb line.
Hence, in low latitudes, rhumb lines and great cir-
cles are very nearly coincident.
A more quantitative comparison of rhumb line
and great circle distances has been made by actual
computation of the difference in distance between
the two paths for various possible flights, as shown
on the graphs.
DISTANCE =~ Hone"
2.0
DIFFERENCE >
(NAUT. Mi) 1.0 os =
———————— | area"
0 160 200 300 400 500 600 700 800
RHUMG LINE DISTANCE (NAUT.MI.}
FIGURE A is a plot of the differences between rhumb line
and great circle distancés, versus the rhumb line distance
for various rhumb line headings. Curves are for flights with
an initial latitude of 50°N., and represents “average” flights
at “average” latitudes.
40 .
3.0 en
DISTANCE
DIFFERENCE 2.0
(NALT. Mi peer ete
60 100 io 120 130 140 150 160 170 180
RHUMB LINE HEADING (DEGREES)
FIGURE B is a plot of the distance difference versus rhumb
line heading for a 500 mile flight with an initial latitude
of 70°N. Distance difference increases with increasing lati-
tude, and is also a function of heading. At low latitudes
the distance difference is a maximum for some heading
intermediate between 0° and 90° since at these latitudes
Considering that most flights are made well below
70° and that fiights along rhumb line paths need not
exceed 500 miles in length, indications are that -a
rhumb line computer solution is an extremely good
the parallels of latitude approach rhumb lines, and the
meridians (Hgr—0*) are both great circles and rhumb lines.
At higher latitudes however, only the meridians are both
thumb line and great circles, so the distance difference is a
maximum for headings near 90°.
approximation of the shortest distance. Also, the
Polar Heading Adapter, (page 22) extends these
same considerations to the terrestrial polar areas.
19
“ASN‘7 satisfies modern flight needs
HUMAN ENGINEERED—OPTIMUM
OPERATIONAL ENVIRONMENT
An integrated control and display panel provides the operational environment that
permits the pilot to concentrate on the most vital mission aspects.
This means data should be presented in a form that is readable, unambiguous,
non-redundant, in order to shorten the link between observation and control; related
functions are combined in a single display; most-often-used controls and displays are
given priority. The ASN-7 has many ‘human-engineered’ features:
Knobs and switches have different “feel”,
Provision for fast or slow slewing.
Warning flags are safety feature.
Numerals are extra large for better visibility.
Pilot has right control “feel” even when wearing heavy gloves.
One indicator presents all vital navigation information.
Counters synchronize instantaneously, upon switchover from
Present Position to Destination (or vice versa).
VERSATILITY
Fly over all terrain, all weather, under all environmental conditions, without inter-
mediate fixes.
Variation information can be inserted automatically or manually.
Unlimited range through enroute insertion of destinations.
Accessories are available for polar navigation, automatic fix correction, and
extraction of drift angle and ground speed from general purpose radar.
RELIABILITY
COMPONENTS
Completely transistorized.
No heaters.
No blowers.
Five of the seven boxes are hermetically sealed.
Guaranteed life over 1000 hours.
Shelf life of seals—--over five years.
Operational reliability has been demonstrated.
ENVIRONMENTAL TESTS
ASN-7 operates between —65° F and 160° F.
Designed for operation at altitudes up to 50,000 ft.
Equipment withstands vibration of 5 to 500 cps.
Withstands shock of 10 G's.
Non-magnetic.
No radio noise problems.
It is built to withstand dust, sand, fungus and humidity and
other factors required by mil spec MIL-E-5272A.
20
“Switch-on-check” takes
only 30 seconds.
System uses “Go-no-go” checker for
line maintenance.
Test unit for Depot repair and
maintenance is portable and fly - away,
and completely self-contained.
Maintenance is easy.
Amplifier modules simplify maintenance.
Fuses are easily replaced and spares
are contained in units. ,
Troubles can be easily pin-pointed.
Test set indicates not just trouble,
but source of trouble.
ACCESSORIES
UNDER DEVELOPMENT
POLAR HEADING ADAPTER
The Polar Heading Adapter supplies true heading
under a variety of operating conditions. Automatic
navigation equipment operation in Polar regions
is restricted by two things: First, magnetic storms
and the small horizontal component of the earth’s
field make compass indications erratic and inaccu-
rate, and second, the rapid convergence of longitu-
dinal meridians requires excessive rates of those
portions of the equipment concerned with longitude.
Polar Heading Adapter facilitates automatic naviga-
tion in the polar regions by computing necessary
corrections to directional gyro or magnetic heading
information and supplying a suitably corrected, accu-
rate heading output at all latitudes for use in a navi-
gational computer. The necessary electrical and
mechanical components are contained in a single
hermetically sealed remotely located unit. A modi-
AUTOMATIC FIX CORRECTOR
The recently evolved concept of ground correcting
the airborne navigation computers permits the use
of the Automatic Fix Corrector in the terminal area,
where errors have accumulated during flight. When
the position error and the time within which it is
accumulated are employed to correct the manually
set-in wind, the computer may be used on the out-
going leg of a mission with reasonable assurance
that the last set-in wind information is correct. This
is the function for which the Automatic Fix Cor-
rector was designed.
Position information is received from a digital data
link, which in turn is fed into the AFC. This data
is compared with the computed position, and in con-
junction with a time interval, is used to compute
ADAPTER, GROUND SPEED AND DRIF
This instrument works in conjunction with any
search radar already installed in the aircraft, or with
a fire control radar whose antenna system may be
tilted for ground coverage. As a result, no extensive
structural modifications to the airframe normally
associated with a new radar installation are called
for.
The Adapter can supply ground speed and drift
Kk
fied compass control panel located in the cockpit
contains necessary mode switching and controls.
The Polar Heading Adapter operating in conjunction
with an ASN-7 will do the following:
1) Accept heading inputs from slaved magnetic
compass or directional gyro.
2) Calculate true aircraft heading with high accu-
racy in either true or transverse coordinate sys-
tems and thus enable all latitude navigation with
greater accuracy.
3) Coordinate-convert from transverse coordinate
inputs to true coordinate (lat & long) outputs
which are available to other equipments (e.g.
astro tracker). :
4) Calculate Pe (polar correction angle—the angle
of transverse north pole from true north pole as
a function of position).
an effective wind. The position correction and the
suitably weighted effective wind are then inserted
into the ASN-7.
Should the winds shift during a given interval of
time, a new position and wind correction factor are
made upon receipt of the next position fix. Manually
inserted fixes can also be used to compute a weighted
effective wind. These fixes would be achieved by
flying over two separate check points. This versa-
tility allows for computation of winds in areas where
no data link equipment is available.
Ford estimates that production models of the Auto-
matic Fix Corrector will weigh approximately 12.5
pounds and occupy 175 cubic inches,
ANGLE
angle information as dial indication, as a voltage
suitably scaled for use in associated navigation
equipment, or as a combination of these two
methods. The information is supplied completely
automatically, either continuously or upon demand.
Except for the display device, if any, the equipment
can be remotely located, It requires no in-flight
or pre-flight alignment. It does not call for human
supervision at any time.
In this able; Fovd ostrmoment's. ASN27
designed for airorme application
_ THE ASN-7 COMPARED
(Az of Naver bey
94
ts compare? te “four athe ccuirse and dithnée cSmiputers
COMPUTER | COMPUTER | COMPUTER | COMPUTER
FEATURES ASN-7 A B c ; D
Continuous Display of Yes Yes Yes Yes. - Yes
Course and Distance
Continuous Display of Yes Yes Yes
Present Position
Fully Transistorized Yes Yes Yes Yes ‘Yes
Compatible with Doppler Radar Yes Yes
Weight Under 70 Pounds Yes Yes Yes Yes
Course and Distance Accurccy Yes Yes
Better than 6 Mile Circle
in 1000 Miles
Present Position Accuracy Yes Yes Yes
Better than 1-1/2% of
Distance Traveled 4
+
in Full Production Yes
Operational Type Ground Yes
Suppert Equipment Available |
Now in Operational Aircraft Yes |
\)
‘
7
Ford Instrument Company is a division of Sperry Rand
Corporation. It is organized primarily to develop, design,
and produce high precision control and computer systems
for military and commercial applications, Ford has an
extremely diversified background in automatic weapons
control. The techniques it has developed have had a great
influence on the nature of modern warfare.
Ford abilities range from development and production
of naval, missile, land based and airborne controls and
computers to data processing systems, nuclear reactors and
ever-increasing automatic control applications.
Four decades of experience, and large manufacturing facilities,
enable the company to handle complex research, development and
production contracts with smooth coordination.
FORD INSTRUMENT COMPANY
DIVISION OF SPERRY-RAND CORPORATION
BIAS Thoemsaw AgGenne *€ USirg fstand City 4. Newtcyesire