NAVIGATION SYSTEMS
MARK FUNCTION
Together the CDU and LASTE can create two different kinds of mark points: overhead mark points (directly below aircraft) and offset mark points (an object offset from aircraft position).
Creating Overhead Mark Points.
To create an overhead mark point:
NOTE
•
CDU cannot be displaying NI mode.•
EGI INS must be in NAV mode.•
IFFCC must be turned on and functioning to obtain valid mark point elevation data.a. LCP - RDR ALTM switch - NRM.
b. Stick Grip - Master Mode Control Button - Depress to select - GUNS, CCIP, CCRP, or NAV.
c. CDU - Verify UPDATE Page not displayed.
d. CDU - MK button - or UFC MK pushbutton Depress at flyover. The position of the point overflown is stored in the mark point portion of the waypoint database in location A, B, C,....etc. MARK A (B, C,....) will be an-nunciated on the CDU for 10 seconds or until the FA pushbutton is depressed; and, on the HUD, the steer-point identifier, number, and distance fields will flash for approximately 5 seconds, and the mark point eleva-tion (or XXXX if above 5000 feet AGL) is displayed
the MK pushbutton on the CDU will result in an over-fly mark regardless of the HUD format.
NOTE
•
There are 25 mark points available (A thru Y). The 26th mark point (Z) is reserved for LASTE weapons event mark points. The 26th mark point will overwrite the data in the A position. The 27th mark point will overwrite the B position, etc. Each succeeding LASTE weapons event mark point will overwrite the data in the Z position.•
All mark points are initially displayed using the last spheroid model selected.•
If marks are taken less than one second apart, the elevation may not be accurate and "*****"will be displayed for elevation.
Creating HUD Offset Mark Points.
To designate points as mark points without flying directly over-head, proceed as follows:
NOTE
•
Offset mark accuracy is maximized when ac-complished in a non-maneuvering state with the target or steerpoint near the Total Velocity Vector (TVV).•
When an offset mark point is to be created, the altitude of the mark point must be at least 1 foot below the LASTE system current al-titude, the mark point must be less than 14.8 NM slant range (for Hot Target elevation) and 10 NM ground range (for DTS mode) from the aircraft, and the mark point must be at least 5 mils below the horizon.•
LASTE must be turned on and functioning and the aircraft must be in the air to create off-set mark points.•
The Maverick symbol, when outside the HUD Field of View (FOV), can be used to create an offset mark. However, the mark point is only as accurate as the look-angle received by LASTE from the Maverick.b. Stick Grip - Master Mode Control Button - Depress to select - GUNS, CCIP, CCRP, or NAV.
NOTE
Although the system will create an offset mark point in the LASTE NAV mode, EGI will use the aircraft’s barometric altitude for the compu-tation. This will, in most cases, produce a mark point that is significantly less accurate than one taken from GUNS, CCIP, or CCRP mode.
c. AHCP - ALTITUDE switch - Select desired altitude source.
NOTE
When the RADAR mode (aircraft below 5000’
AGL) is selected, the system will create an accu-rate offset mark point only when the mark point elevation is the same as the terrain elevation un-derneath the aircraft.
d. Set LASTE elevation to elevation of intended mark point or select DTS.
e. Use Slew Enable Switch to move the Target Designa-tion Cue (TDC) - As required.
f. Slew TDC over the intended mark point. If the TDC is not slewed from the TVV, the TDC must be flown to the intended mark point and ground stabilized using TMS-FWD/SHORT.
g. Stick-TMS-RIGHT/SHORT to send offset markpoint position to the CDU. The position of the offset mark point is stored in the mark point portion of the way-point database in location A, B, C,.…, etc. MARK A (B, C,....) will be annunciated on the CDU.
NOTE
•
The CDU MK button or UFC MK button can-not be used for creating offset mark points. It will create an overfly mark regardless of the HUD mode.•
There are 25 mark points available (A thruweapons event mark point will overwrite the data in the Z position.
•
All mark points are initially displayed using the last spheroid model selected.Selecting Mark Points.
To select a mark point as the steerpoint:
a. AAP - STEER PT select rotary knob - MARK.
b. To change the steerpoint, either:
(1) Go to the Steerpoint Information (STRINFO) Page (Figure 1-60) and enter the letter corre-sponding to the mark point to be used, and de-press the steerpoint LSK, or
(2) Use the STEER toggle switch on the AAP to change the steerpoint to the desired mark point.
c. To display mark point coordinates, go to the Waypoint (WAYPT) Pages (Figure 1-63) and either:
(1) Enter mark point letter in scratchpad and de-press waypoint LSK.
(2) Use the ± rocker switch on the CDU or the FUNC mode of the SELECT switch on the UFC to display the desired mark point, or
(3) Use the Waypoint Search Procedure and the waypoint identifier LSK to display the desired mark point.
Offset Displacements.
The OFFSET Page (Figure 1-66) can be used to compute dis-placements between waypoints, between a waypoint and entered geographic data, and to generate a new waypoint at a specified offset from an existing waypoint.
a. To compute offset between waypoints:
(1) Select the initial waypoint using the initial way-point database and number or identifier LSK.
(2) Select the second waypoint as the offset way-point using the offset wayway-point database and
b. To compute the offset between a waypoint and entered geographic data:
(1) Select initial waypoint using the initial waypoint database and number or identifier LSK.
(2) Enter the desired geographic data using the off-set waypoint latitude and longitude LSKs, or the offset waypoint MGRS grid and spheroid and area, eastings, and northings LSKs.
(3) The offset will appear as the magnetic head-ing/distance below MH/DIS:
c. To generate a new waypoint at a specified offset from an existing waypoint:
(1) Select initial waypoint using the initial waypoint database and number or identifier LSK.
(2) Enter the offset heading and distance as HHHDDDDT and depress the magnetic head-ing/distance (MH/DIS) LSK.
NOTE
•
Entry procedure for MH/DIS is identical for L/L or MGRS coordinate format.•
Keyboard entry format for MH/DIS is HHHDDDD.T, where:HHH is magnetic heading in whole degrees, enter one leading zero if less than 100°, two if less than 10°.
DDDD is distance in nautical miles (NM), be-tween 0000 and 9999.
T is fractional NM in tenths; use the decimal point (.) to enter tenths. Tenths of a NM may always be entered, but will only be displayed when distance is less than 100 NM. Although tenths of a NM will not be displayed when entered distances are greater than 99.9 NM, the tenths will be used in the computation of the geographic data.
(3) Geographic data for the offset waypoint will ap-pear in the geographical data fields. This data can be copied into a new waypoint by depress-ing the copy (?XX) LSK where XX is the num-ber of the next available mission waypoint, or overwriting an existing mission waypoint by en-tering 1-50 or a waypoint identifier (up to 12
alphanumeric characters) on the scratchpad and pressing the Copy LSK. If an identifier is en-tered that does not match an existing identifier, the new mission point’s identifier will be as-signed the entered identifier. If the mission point does exist, the identifier will not be overwritten.
If an identifier is not entered into the scratchpad, and the mission point being copied to does not currently exist, the identifier MSNOXX (where XX is the next unused mission number) will be assigned the new waypoint when the copy LSK is depressed. The created waypoint will contain steering attributes on WAYPT Page 2/2 (Fig-ure 1-63) that are the current steering attributes (the attributes the system is using at the time the waypoint is created).
NOTE
As the waypoint identifier is entered in the scratchpad, the waypoint search function will be initiated after the first two characters are entered and after each succeeding character is entered.
For details, refer to the Waypoint Search Proce-dures paragraph.
Overhead Update.
A manual overhead update of the EGI INS can be accomplished as follows:
NOTE
•
If overhead update is accepted, only the INS-only solution is updated, the blended solution is not changed.•
If overhead update is accepted, RER and CEP will not be computed upon landing.•
LASTE must be turned on and functioning to obtain valid update point elevation data.a. LCP - RDR ALTM switch - to NRM.
b. AHCP - IFFCC Switch - to ON.
c. AAP - PAGE select rotary knob - Select OTHER.
d. CDU - Depress SYS function select key, if necessary.
Observe System (SYS) Page (Figure 1-80) is displayed.
e. CDU - SYS Page - Depress INS Page LSK. Observe INS Page (Figure 1-89) is displayed.
f. CDU - INS Page - Depress UPDATE page LSK. Ob-serve UPDATE Page (Figure 1-75) is displayed.
NOTE
The UPDATE Page can also be selected from the NAV Page (Figure 1-70).
g. CDU - UPDATE Page - Depress PROCEED LSK (if PROCEED and its target symbol are present). Observe that PROCEED and its target symbol disappear, and the system downmodes to INS-only mode (I displayed next to FOM line 1).
NOTE
If system is already in INS-only mode, PRO-CEED and its target symbol will not be present;
proceed to Step i.
h. CDU - Depress MK pushbutton when directly over selected (current) steerpoint. Observe Accept/Reject (ACC/REJ) Page (Figure 1-76) is displayed.
i. CDU - ACC/REJ Page - Accept or reject update using ACCEPT or REJECT LSK.
NOTE
•
If the update is neither accepted nor rejected within 30 seconds, or a different page is se-lected within 30 seconds, the update will be automatically rejected. Depressing REJECT LSK causes update to be rejected and UP-DATE Page to be redisplayed.•
Once the INS-only mode is entered and with the UPDATE Page displayed, any number of overhead updates can be performed. Any page other than the UPDATE Page must be dis-played to prevent overhead updates from be-ing initiated when the CDU MK button is de-pressed.j. To return to the original blended solution, proceed as follows:
(2) CDU - Depress NAV function select key. Ob-serve NAV Page (Figure 1-70) is displayed.
(3) CDU - NAV Page - Use commanded mode LSK to select BLENDED.
INS HUD Update (Offset Update).
An INS HUD update of the EGI INS can be accomplished as follows:
NOTE
•
INS HUD update accuracy is maximized when accomplished in a non-maneuvering state with the target or steerpoint near the TVV.•
If INS HUD update is accepted, only the INS-only solution is updated, the blended solution is not changed.•
If INS HUD update is accepted, RER and CEP will not be computed upon landing.•
When an INS HUD update of the EGI INS is to be performed; the altitude of the update point must be at least 1 foot below the LASTE system current altitude, the update point must be less than 14.8 NM slant range (for Hot Tar-get elevation) and 10 NM ground range (for DTS mode) from the aircraft, and the update point must be at least 5 mils below the hori-zon.•
LASTE must be turned on and functioning and the aircraft must be in the air to perform an INS HUD update.a. LCP - RDR ALTM switch - Select NRM.
b. AHCP - IFFCC Switch - to ON.
NOTE
Although the system will update the EGI INS in the LASTE NAV mode, EGI will use the air-craft’s barometric altitude for the computation.
This will, in most cases, produce an offset update
c. AHCP - ALTITUDE switch - Select desired altitude source.
NOTE
When the RADAR mode (aircraft below 5000’
AGL) is selected, the system will perform an ac-curate INS HUD update only when the steerpoint elevation is the same as the terrain elevation un-derneath the aircraft.
d. AAP - PAGE select rotary knob - Select OTHER.
e. UFC - FUNC/MK {UPDT} - Depress once and observe HUD displays HUD UPDATE, and on CDU, system downmodes to INS-only mode (I next to FOM on line 1).
f. Use Slew Enable Switch to move TDC - As required.
g. Slew TDC symbol on selected (current) steerpoint and depress UFC ENT. Observe Accept/Reject (ACC/REJ) Page (Figure 1-76) is displayed on CDU, and on HUD, HUD UPDATE message flashes for 2 seconds and then disappears, and target designation (TD) box moves to selected (current) steerpoint.
h. CDU - ACC/REJ Page - Accept or reject update using ACCEPT or REJECT LSK.
NOTE
If the update is neither accepted nor rejected or a different page selected within 30 seconds, the update will be automatically rejected. Depress-ing REJECT LSK causes update to be rejected and page that was displayed prior to ACC/REJ Page to be redisplayed.
i. To return to the original blended solution, proceed as follows:
(1) CDU - Depress NAV function select key. Ob-serve NAV Page (Figure 1-70) is displayed.
(2) CDU - NAV Page - Use commanded mode LSK to select BLENDED.
INS TGP Update.
An INS TGP update of the EGI INS can be accomplished as follows:
NOTE
•
INS will only be displayed on the TGP A-G Page (OSB 10) when the EGI is in an INS-only navigation mode.a. CDU - select update point as current steerpoint b. MFCD - TGP A-G Page - Track ground position of the
current steerpoint.
c. MFCD - Press INS (OSB 10).
d. MFCD - Press INS (OSB 10) again within 3 seconds to acknowledge the INS update and send the TGP position information to the CDU.
e. CDU - Accept/Reject page is shown with the calculated offset.
f. CDU - ACC/REJ Page - Accept or reject update using ACCEPT or REJECT LSK.
NOTE
If the update is neither accepted nor rejected or a different page selected within 30 seconds, the update will be automatically rejected. Depress-ing REJECT LSK causes update to be rejected and page that was displayed prior to ACC/REJ Page to be redisplayed.
LRU Reset.
If the CDU has determined that an LRU (EGI, LASTE, CADC, HARS, or DTS) has failed (F) or not communicating (N), the CDU will not use data from that LRU in forming the ENAV solution. Attempt to reset the failed LRU as follows:
a. Reset the CDU’s failure determination by depressing the failed LRU LSK on the RESET Page (Figure 1-87).
b. The CDU resumes monitoring the LRU indicators that it uses in determining LRU status. If the cause of the original failure no longer exists, the LRU status will continue to indicate V. If the cause of the original failure is still present, the LRU indicators will once again result in a failure (F or N) status for that LRU.
LRU Reinitialization.
Reinitialization of the INS, GPS, or LASTE can be performed by depressing the corresponding LSK on the Reinitialization (REINIT) Page (Figure 1-81).
NOTE
If the aircraft is on the ground, reinitialization is identical to the original power up initializa-tion. For GPS, in-flight reinitialization is iden-tical to the original power up initialization. If INS reinitialization is performed in the air, an IN-FLT alignment is performed instead of a normal alignment. LASTE cannot be reinitialized via the REINIT Page when airborne.
LRU and CDU Tests.
The LRU and CDU tests are selected and controlled by the LRU Test (LRUTEST) Page (Figure 1-101), EGI Test (EGIT-EST) Page (Figure 1-102), CDU Test (CDUT(EGIT-EST) Pages (Fig-ure 1-103), Bitball Control (BB CTL) Page (Fig(Fig-ure 1-104), and BITBALL Page (Figure 1-105), which are provided for refer-ence only. These pages are active only on the ground. Do not use any of these pages prior to flight; the only way to exit these pages, if a test has been selected, is to cycle CDU power. These pages contain maintenance information for use by maintenance personnel. For information pertaining to these pages, refer to Troubleshooting Avionics Integrated Systems - Navigation Sys-tems, TO 1A-10C-2-40TS-3.
Do not select any of the LRU or CDU test(s) prior to flight. Some of these tests can cause the rudder to move prior to takeoff.
CDU Bitballs.
When a failure occurs within the CDU, the CDU display could freeze, go blank, or a DISPLAY FAILURE, MBC FAIL, ADA FAIL, or HARDWARE FAIL message could appear on the screen. If this failure occurs during flight, power to the CDU can be cycled. If the CDU powers on again, a bitball (Δ) will appear in the top right-hand corner of all pages. The bitball alerts ground crew personnel that a failure occurred in the CDU. Maintenance personnel then can examine the last five BITBALLs via the Bitball Control (BB CTL) Page (Figure 1-104) and BITBALL Page (Figure 1-105).
Access To Miscellaneous EGI INS Data.
EGI INS miscellaneous data can be accessed on the INS Page (Figure 1-89). To read the data at a particular address, enter the address in the scratchpad and depress the MISC LSK. The data appears next to the bottom right LSK. To write data to a particu-lar address, first select the address using the scratchpad and the MISC LSK. Then enter the data in the scratchpad and depress the bottom right LSK. The data is written to the selected address.
This LSK is for use by maintenance personnel only.
FOM.
The FOM for the selected navigation solution is displayed on the right side of line 1 on all CDU operation display pages. The EGI Page 1/4 (Figure 1-88) displays the INS-only, GPS-only, and blended (BLD) navigation solutions FOMs. The FOM for the BLENDED and GPS-only solutions is a number that repre-sents the 3-dimensional estimated position error (spherical error probable (SEP)) as listed below:
FOM Estimated Position Error 1 Less than 85.3 feet (26m).
2 Greater than 85.3 feet (26m) to 164.1 feet (50 m).
3 Greater than 164.1 feet (50 m) to 246.1 feet (75 m).
4 Greater than 246.1 feet (75 m) to 328.1 feet (100 m).
5 Greater than 328.1 feet (100 m) to 656.2 feet (200 m).
6 Greater than 656.2 feet (200 m) to 1640.5 feet (500 m).
7 Greater than 1640.5 feet (500 m) to 3281.0 feet (1000 m).
8 Greater than 3281.0 feet (1000 m) to 16405 feet (5000 m).
9 Greater than 16405 feet (5000 m).
NOTE
The FOM for the INS-only solution is a time de-pendent number which gradually increases with time.
List Of ENAV CDU Display Pages.
Figure 1-57 illustrates the ENAV CDU display pages menu tree.
The following is a list of figures of the ENAV system CDU display pages that can be used.
FIGURE
NUMBER FIGURE NAME
PAGE NUM-BER Figure 1-58 CDU Header Line Display 1-148 Figure 1-59 Position Information
(POSINFO) Page
1-149
Figure 1-60 Steerpoint Information (STRINFO) Page
1-151
Figure 1-61 Waypoint Information (WP INFO) Page
1-155
Figure 1-62 Waypoint Menu (WP MENU) Page
1-158
Figure 1-63 Waypoint (WAYPT) Pages 1-160
Figure 1-64 ANCHOR Page 1-168
Figure 1-65 FROM Page 1-171
Figure 1-66 OFFSET Page 1-174
Figure 1-67 Flight Plan Menu (FPMENU) Page(s)
1-178
Figure 1-68 Flight Plan Build (FPBUILD) Page(s)
1-181
Figure 1-69 Waypoint Attributes (WPTATT) Page
1-185
Figure 1-70 Navigation (NAV) Page 1-190 Figure 1-71 Diversion (DIVERT) Page 1-191 Figure 1-72 Airfield Information
(FLDINFO) Page
1-193
Figure 1-73 ALIGN Page 1-195
Figure 1-74 TIME Page 1-200
Figure 1-75 UPDATE Page 1-206
Figure 1-76 Accept/Reject (ACC/REJ) Page 1-208 Figure 1-77 DTS Upload (DTSUPLD) Page 1-210 Figure 1-78 Attributes (ATTRIB) Page 1-213
Figure 1-79 OPTIONS Page 1-217
Figure 1-80 System (SYS) Pages 1-219 Figure 1-81 Reinitialization (REINIT) Page 1-222
FIGURE
NUMBER FIGURE NAME
PAGE NUM-BER
Figure 1-82 LASTE Page 1-224
Figure 1-83 Wind/Temperature Profile (WIND) Pages
1-227
Figure 1-84 Wind/Temperature Profile Edit (WNDEDIT) Pages
1-231
Figure 1-85 HARS Page 1-234
Figure 1-86 CADC Page 1-236
Figure 1-87 RESET Page 1-238
Figure 1-88 EGI Pages 1-239
Figure 1-89 INS Page 1-243
Figure 1-90 Alternate Align (ALTALGN) Page
1-245
Figure 1-91 Position (POS) Page 1-250 Figure 1-92 INS Status (INSSTAT) Page 1-252 Figure 1-93 Digital Terrain System
Application Software (DTSAS) Page
1-255
Figure 1-94 GPS Page 1-258
Figure 1-95 GPS Status (GPSSTAT) Pages 1-261 Figure 1-96 GPS BIT (GPSBIT) Pages 1-265 Figure 1-97 GPS Keys (GPSKEYS) Page 1-269
Figure 1-98 DTS Page 1-270
Figure 1-99 DTS Download (DTSDNLD)
Figure 1-99 DTS Download (DTSDNLD)