DCS F-18 - Navigation Systems

[VBF-12 Gosling]

Gents

I will cover the basics of naviagation in the following posts, to include the setup and use of the systems within the Hornet.

N01 - Navigation System
N02 - HSI Display
N03 - Air Direction Finding (ADF)
N04 - TACtical Air Navigation (TACAN)
N05 - TACAN Database
N06 - Air to Air TACAN
N07 - Waypoints
N08 - Waypoint Sequences
N09 - Waypoint Database and Editing
N10 - Designation of a Waypoint as a target
N11 - Time on Target (TOT)
N12 - Waypoint Offsets
N13 - Instrument Carrier Landing System (ICLS)
N14 - Terrain Avoidance Warning System (TAWS)
N15 - Ground Proximity Warning System (GPWS)
N16 - anything else I haven’t thought of yet...

[VBF-12 Gosling]

N01 - NAVIGATION SYSTEM

Reference
Chapter 24

Primary System Description
- EGI. The primary sensors for the Hornet navigation system consist of an Embeded Inertial Navigation System (INS) combined with a Global Positioning System (GPS) which is called the EGI. The INS contains an Instrument Measuring Unit (IMU) which has ring laser gyros and accelerometers to sense aircraft movement and provide the Attitude and Heading Reference Set (AHRS). The INS combines the AHRS output with the GPS to provide the EGI position solution.
To this is fed information from the pitot and static system via the Air Data Computer (ADC).
- Air Data Computer. The air data computer receives inputs from the angle-of-attack probes, total temperature probe, pitot static system, standby altimeter barometric setting, air refueling probe position, magnetic azimuth system, mission computer, and landing gear handle position. Accurate air data and magnetic heading are computed. Computed data is supplied to the mission computer system, altitude reporting function of the IFF, engine controls, environmental control system, landing gear warning, and the fuel pressurization and vent system.
- Altitude. Altitude is derived by the ADC from the Pitot Static System for inclusion in the position solution. RadAlt information is also sent to the MC1 and used within many systems including the GPWS, Radar, Weapon System etc.
- Heading. The aircraft’s Flux Compass (Magnetic Azimuth System) provides heading data to the ADC and a database of variation allows calculation of True North.
- ADF. The system also receives input from the Communication System in the form of bearing signals from the Air Direction Finder (ADF). All these inputs are dead reckoned to provide the aircraft movement and are updated by the GPS via Kalman filters which estimate the INS drift error. Thus, if the GPS signal is lost (Eg Mountinous terrain at low level) the INS drift is minimised until GPS is restored.
- TACAN & ICS. For even more accurate navigation the aircraft has a TACtical Air Navigation (TACAN) receiver & transmiter and an Instrument Carrier Landing System (ICLS). These reference signals transmitted from ground station of know location and are more accurate close to the transmitters.
- D/L (Link 4 & Link 16). Finally, the aircraft receives data from the DATA LINK transmitted from the carrier or an AWACS. Including tactical data this allows Automatic Carrier Landing (ACL) to function.
All these equipments are combined within the Main Computers (MC) to provided a position solution displayed on the DDIs, AMPCD and HUD, allowing accurate navigation.

Secondary Systems
Like all Aircraft there are backup systems. For the hornet these include:

• A Standby Attitude Refence System (SARI) - Electrically powered the SARI includes needles to mirror HUD ICLS indications
• A Standby Airspeed Indicator
• A Standby Altimeter - Data to Indicator and ADC
• TAWS - Terrain Avoidance Warning System - Gives ground proximity warning by comparing GPS position against the terrain database, allowing for height, speed and rate of closure to minimise false alarms. EG flying slowly near the ground assumes landing so no warning
• GPWS - Ground Proximity Warning System - Uses ADC output and RadAlt to assess potential of Controlled FLight Into Terrain (CFIT). Warns the pilot of imminent risk and the action required to resolve the risk

Location Reference
The aircraft stores its position relative to standard mapping systems. Primarily this is WGS84 (World Geodetic Standard 1984) which is the most common and used in GPS.

Alignment
Alignment of the Nav System is achieved using the INS Mode Selector knob. Right Centre Consol. The switch positions are:

• OFF - Removes power from the INS
• CV - Carrier align mode with the MC providing the carrier align display
• GND - Ground align mode with the MC providing the ground align display
• NAV - Navigation mode which enables the MC to use INS information to provide navigation steering
• IFA without GPS - Inflight Alignment mode with an IFA display
• IFA with GPS - Aided INS (AINS) position keeping or GPS inflight alignment with an IFA display
• GYRO - AHRS (Attitude Heading Reference Set) mode
• GB - Gyro bias mode enabling the INS to do a gyro bias calibration
• TEST - Enables the INS to perform an initiated BIT upon command from the MC

There are three types of INS alignment modes by selecting:

• CV - 3 types of CV alignment
  • RF (Radio Frequency) or CBL (Cable) uses data linked to the SINS (ships inertial navigation system) which flashes until valid
  • MAN (Manual) where the Carrier Position (POSN), Heading (CHDG) and Speed (CVEL) data is entered through the UFC
  
  [li]GND - Parking Brake must be ON. Select INS Mode to GND
• IFA -

Alignment Process
CV RF (D/L align freq is on UFC scratchpad for 30 secs) or CV CBL or GND or IFA
QUAL: NO ATT - while INS levels, then qq.q decreasing until OK = Alignment complete - Select NAV
TIME: mm:dd - counting Up, < 10 mins. If interrupted the TIME stops and flash.
NO WYPTS or WYPTS - If waypoints are transmitted from ship during CV RF or CV CBL alignment. After 20 seconds NO WYPTS if waypoints have not been received.
Some of this may not be implemented as yet

Nav System Controls
Primary control of the nav system is via the UFC and DDI. UFC. The UFC allows ON/OFF operation of the ICLS, TACAN, D/L, and ADF. data entry for
the TACAN, GPS, and INS; and mode selection for the D/L. These can also be controlled manually by deselection of UFC on the Navigation Panel (left rear consol). Settings for the TACAN, ICLS and ADF can be set with this panel.

[VBF-12 Gosling]

N02 - HSI DISPLAY

Description
The Horizintal Situation Indicator (HSI) display is the main output if the Navigation Systems. I will add more about the system units and how it works in more detail in due course...

HSI Symbology
The HSI consists of:

• Compass Rose with heading markers at 10 degree intervals around its circumference. The ones at the main 30 degree intervals are also marked with their bearing or cardinal as appropriate
• Your position and direction of flight is marked by an aeroplane symbol, usually in the centre
• TAS (nnnT)- Your current TAS is displayed to the left of your plane symbol
• GSpd (nnnG)- Your current GSpd is displayed to the right of your plane symbol
• Lubber Line - Top dead centre when in Track Up (TU), against which your heading can be assess from the rose
• Heading Marker - This is a double square which can be set using the Heading Switch at the bottom left of teh UFC
• HSEL ddd - In the bottom left is a digital readout of teh current Heading Marker position. Selection of the Autopilot (A/P) :HDG hold will cause the aircraft to turn to this heading
• Course Line - Using the CRS switch on the bottom right of the UFC causes a course line to pass through the selected TACAN (if ON and Tuned)
• CSEL nnn - A digital readout of the selected CRS bearing is displayed in the bottom right of the display
• Waypoint Brearing and Range (ddd / DDD.D) - In the top right corner
• Time To Go (TTG) - To the selected waypoint is displayed in hh:nm:as to the top right below the waypoints bearing and range
• TACAN Bearing and Range (ddd / DDD.D) - In the top left corner
• Time To Go (TTG) - To the selected TACAN is displayed in hh:nm:as to the top left below the TACAN bearing and range
• TACAN Code - The three letter code of the TACAN is displayed top left below its TTG

HSI Options
Right Options:

• WPT (R1) - When boxed passes Waypoint information to the HUD
• Up Arrow (R2) - Waypoint Selection
• Number below Up arrow - Selected Waypoint
• Down Arrow (R3) - Waypoint Selection
• WPDSG (R4) - Designate selected waypoint as a target. WPT at R1 becomes TGT and is boxed. The WPT shows at a target diamonsd in the HUD
• SEQ (R5) - Selection of one of three Waypoint Sequences

Left Options:

• TCN (L1) - When boxed sends TACAN information to the HUD
• ICLS (L2) - When boxed sends ICLS information to the HUD and the EADI
• MODE (L3) - HSI display mode. See below
• VEC (L4) - This allows access to the Data Link controls for Link 16 (L3) and Link 4 (L5). L4 allows RETURN to the previous display. Once a Data Link is selected VEC will be boxed. I dont know much about this yet
• ACL (L5) - Auto Landing System - Yet to be implemented - when boxed sends ACL information to the HUD[li]
  

Bottom Options:

• SENSORS (B1) - Sensor Options - Not yet implemented
• Blank (B2) -
• 3349 - Main Menu(B3) - I have no idea why it says 3349?
• TIMEUFC (B4) - For HUD Clock
• AUTO - Automatically Setup to the next waypoint when close to the selected waypoint. This is NOT a flight director. The aircraft will NOT automatically turn

Top Options:

• POS/ (T1) - Options; INS (T1), MIDS (yet to be implemented(YTBI)), ADC(T2), TCN(T3), AINS(YTBI) or GPS(YTBI) as the position keeping source
• UPDT (T2) - Update source options; VEL(velocity)(L1), TCN(T1), GPS, DSG(designation)(T2), AUTO(T3), or MAP(T4)
• SCL/40 (T3) - Scale/40 - Cycle scale of HSI through default 40 / 20 / 10 / 5 / 320(DCTR Mode only) / 160 / 80 and back to 40
• MK1 - 9 (T4) - Location mark. Maximum of 9 locations. The tenth use of Mark replaces Mk1.
• DATA (T5) - Display waypoint detai from database

HSI Display Modes
The HSI can display in a number of modes that combine. They are selected from teh MODE (L3) option:

• T UP (L1) - Track Up - This is the default mode and has the aircraft centered and always pointing up with teh compass turning aroudn the aircraft
• N UP (L2) - North Up - This is wherre the aircraft is still in the centre but the compass is still and the aircraft spins inthe cnetre depending upon its heading
• MAP (L3) - Map Underlay - This places map under the HSI display. The Map scales to diferent version depending upon the SCL/nn selected at (T3). They are usually JOGAIR Charts. The Map will ONLY underlay on the AMPCD. This mode has no effect on the L and R DDIs
• DCTR (L4) - Decentre - This is where the aircraft is at the bottom of the screen and only the ahead sector is visible. The compass now is an arc of 60 degrees. However the Range Scale can now extend to 320nm
• SLEW (L5) - Slew - It is based on DCTR mode but the display can be slewed using the normal slew controls for the radar (I think)

[VBF-12 Gosling]

N03 - AIR DIRECTION FINDING (ADF)

Description
This is a very simple system that uses a received radio signal from a beacon on the ground to give a bearing display on the Hornet’s HSI. The signal is recieved through one of the aircraft’s radios and the morse code identifier of the beacon can be heard through the radio.

HSI Symbology

• Circle (outside of compass rose) = Heading towards ADF Beacon

UFC Symbology
Radio Channel ... ... ... ... Set “M”
Beacon Frequency . ... ... nnn.nnn / ENT
ADF Switch ... ... ... ... ... Select Radio 1 or 2 as req’d

Aircraft Setup
On a DDI:
Select HSI ... ... ... ... ... ... Menu (b3) / HSI (L4)

On a radio: (STIM)
SELECT - Select ADF ... ... ... ... ... ... Switch to ADF 1 or 2 for the required radio
TUNE - UFC Set Manual Freq ... ... ... “M” Channel / Freq = nnn.nnn / ENT
IDENTIFY - Check Beacon . ... ... ... ... Confirm Morse Code of Beacon
MONITOR - HSI .. ... ... ... ... ... ... ... ... Observe “O” Symbol and listen to Morse Code of Beacon

This signal only gives bearing. There is no indication of distance other than passing overhead when the “O” symbol will swing around the HSI to the opposite side.

Training Video (First part of video - 0:45 to 1:44)

[VBF-12 Gosling]

N04 - TACAN

Description
A Tactical Air Navigation (TACAN) beacon is a transmitter that radiates a signal to give a bearing and range to a receiver mounted within the Hornet and other military aircraft. These beacons are generally sited at geographic locations like airfields but can also be on ships, like carriers. They are separated by one of 126 channel numbers and “mode”. The modes are either ‘X’ or ‘Y’ giving potentially 252 different beacons. Generally surfaced base transmitters are X mode and airborne transmitter are Y. There is also an Air to Air mode for tankers and other aircraft. Tankers can have the direction information equipment and so give a bearing and range.

Modes
The Hornet has three modes of operation.

• T/R - Transmit and Receive = Brg and Rng - Also transmits a TACAN signal allowing Rng information to be received by another aircraft on the channel +63 from the one selected in the transmitting Hornet. ie. If you are on Ch12 another aircraft can get range on you only on Ch75.
• REC - Receive = Brg only
• A/A - Air to Air = Rng only

Course Line
A Course Line (CRS) through the TACAN can be setup to guide a selected approach heading. This is very useful when approaching the carrier as it can be set to the Base Recovery Course (BRC).

DDI Symbology

• Triangle = Heading marker to beacon (inside of compass rose)
• Rectangle = Tail of Heading (inside of compass rose) = Away from beacon
• TACAN Symbol = Location of TACAN within the HSI or giving the direction on the inside edge of the compass rose, if out of range of the HSI range scale
• Brg & Rng = Top Left - Next to the TCN option
• Time to Go (TTG) to on top the beacon = Top Left below Brg & Rng
• TACAN Code = Top Left below TTG
• Off Track Distance = ?
• CRS Line = Line through Tacan on chosen course
• CSEL = Bottom Right CRS Selected
• Passing On Top = 180 degree swing of the Triangle and Rectangle

HUD Symbology

• Heading Marker = Top of HUD under heading tape
• Range (nm) = Right of HUD
• TACAN Code = Right of HUD
• CRS Arrow = Alignment of the CRS relative to the aircraft. Displaces from centre by bearing off.
• Bearing from CSE Line = Two Dots on CRS Line SIde = Nearest to centre (4 deg), further from centre (8 deg or greater). As the aircraft crosses the CRS Line these dots will switch to the other side.

UFC Indications

• : - Selected indicator
• T/R - Transmit and receive mode
• REC - Receive Mode
• A/A - Air to Air Mode
• X - X Channels - Mainly Ground Units
• Y - Y Channels - Mainly Airborne Units
• CSEL - CRS Line data entry

Aircraft Setup
On DDI:
Select HSI ... ... ... ... ... ... ... ... MENU (B3) / SUPT (B3) / HSI (L4)
Select TCN . ... ... ... ... ... ... ... TCN (L1) Boxed - Sends TACAN information to the HUD

On UFC (STIM):
SELECT - Select TCN ON ... ... ... ... ... ... TCN button / ON/OFF Button
TUNE - Select Channel ... ... ... ... ... ... ... nn / ENT / :T/R / :X or :Y are req’d
IDENTIFY - Confirm TACAN Code . ... ... Top Left of HSI
MONITOR - Rng & Brg . ... ... ... ... ... ... ... Top Left of HSI and Right of HUD

Setuo CRS Line:
Check TACAN . ... ... ... ... ... ... ... ... ... ... Icon displayed
Select CRS switch . ... ... ... ... ... ... ... ... Left or right for 2 seconds
UFC :CSEL . ... ... ... ... ... ... ... ... ... ... ... Displayed
Enter Req’d Brg . ... ... ... ... ... ... ... ... ... nnn / ENT
Confirm Brg Line . ... ... ... ... ... ... ... ... ... Line displayed
Monitor Off Track Distance . ... ... ... ... ... Bottom Right of HSI ?

Code Word
FATHER = TACAN

Example
“502, Marshal, Mark your FATHER”
“Marshal, 502, Holds MOTHER 250 for 42”

WARNING
If :T/R selected you are transmitting a TACAN signal that can be intercepted by the enemy. Switching TACAN OFF is a FENCE IN Check.

Training Video (Second part of video - 1:45 to 5:12):

[VBF-12 Gosling]

N05 - TACAN DATABASE

Description
The TACAN Database holds the beacon code, location, elevation and magnetic variation of all the TACAN beacons loaded to the aircraft. It is accessed from the HSI Display on the DDI or AMPCD.

Aircraft Setup
On the DDI:
Select HSI display ... ... ... ... ... ... ... ... ... MENU (B3) / SUPT (B3) / HSI (L4)
Select Waypoint Data .. ... ... ... ... ... ... ... DATA (T5)
Select TACAN Database . ... ... ... ... ... ... TACAN (T3)
Cycle to selected TACAN information . ... Up (R3) / Down (R3) Arrows

Edit TACAN Data
Select required TACAN information as above
On DDI TACAN Data Display:
Edit TACAN detail .. ... ... ... ... ... ... UFC (L1)
On UFC:
Enter Position detail .. ... ... ... ... ... :POSN (U3) / Enter Lat (N/S ddmmss) ENT / Enter Lon (E/W ddmmss) ENT
Enter Elevation detail ... ... ... ... ... :ELEV (U4) / Enter Elev (nn in feet) ENT
Enter Magnetic Variation detail . ... :MVAR (U5) / Enter Mag Var (E/W ddmmss) ENT
Note: This does not move the beacon on the ground. It is to correct an inaccurate beacon location in the aircraft’s database.

Training Video (4:25 to 4:50):

[VBF-12 Gosling]

06. AIR TO AIR TACAN

The TACAN can receive signals from other aircraft. The tanker transmits a full TACAN signal but other aircraft only transmit range information.

Aircraft Setup
Setup the TACAN as above.
On UFC:
Select T/R ... ... ... ... ... ... ... :T/R
Select A/A ... ... ... ... ... ... ... :A/A
Select Y .. ... ... ... ... ... ... ... :Y
Select Ch ... ... ... ... ... ... ... nn / ENT

If trying to recieve range from an aircraft other than a tanker select their channel + 63. Buddy must select an unused TACAN Channel. If he selects Ch12 then you must select Ch75 to receive his range only. The BRG indicator will continuously swing. Estimate a closing heading by flying a course to reduce your range to your buddy.

Code Word
YARDSTICK = Transmission of TACAN Range information
Eg. “Skybolt 1-1, 1-2 Request YARDSTICK”
“Skybolt 1-1 is YARDSTICK 12Y, Holding at Angels 250”

Flight profile
Climb to 25,000ft
Assess TACAN Rng increasing or decreasing
Turn to maximise rate of decreasing Rng
Acquire Buddy visually or by own radar

WARNING
If :T/R selected you are transmitting a TACAN signal that can be intercepted by the enemy. Switching TACAN OFF is a FENCE IN Check.

Training Video:

[VBF-12 Gosling]

07. WAYPOINTS

Description
Waypoints are 3D locations in space referenced using a Global Navigation Satellite System (GNSS) like the USA’s Global Positioning System (GPS).

Points are defined laterally using either Latitude and Lonitude or WGS84 Grid. WGS84 is the standard model to divide up the worlds surface into a grid system and is used in almost all military and civilian navigation systems. Defining the point vertically is achieved by defining its height above mean sea level (also modelled in WGS84) in either feet or meters.

HSI Symbology

• Dot & Circle - Selected Waypoint as plan position
• Triangle and Rectangle = Heading and tail of heading to the selected Waypoint including a waypoint inside the HSI Compass Rose
• Brg & Rng - Top Right of HSI
• Time To Go (TTG) to on top the Waypoint - Top Right of HSI below Brg & Reg
• Dashed Line - Flightpath between waypoints of the chosen sequence

- Trouble uploaded, Stby

HUD Symbology
Requires WPT (R1) to be boxed on HSI

• Line (below heading tape) = Heading to waypoint - Remains at full scale deflection of heading is outside it heading tape width
• Distance - Right of HUD
• Wpt Number - To the right of Distance

Training Video:

[VBF-12 Gosling]

08. WAYPOINT SEQUENCES

A total of three waypoint sequences are available for waypoint sequence programming and a maximum of fifteen waypoints may be
programmed in each sequence. These sequences are used for AUTO sequential steering and time on target groundspeed cuing.

Wpt Display
SEQ # (R5) - Bottom Right indicates the waypoint sequence currently in use. SEQ1, SEQ2 or SEQ3
SEQUFC (L5) - Bottom Left initializes the UFC for waypoint sequence programming
A waypoint cannot appear more than once in sequence, however, a waypoint may be entered in more than one sequence
Mark points cannot be programmed in a sequence
Each waypoint entered is placed to the right of the last waypoint in the sequence. If nine waypoints are programmed, the first waypoint in that sequence is deleted and the remaining waypoints move to the left one space. Data for the current waypoint inserted/deleted in the sequence is provided on the waypoint data level display.

Adding a Waypoint
Select waypoint data ... ... ... ... ... ... ... ... DATA (T5)
Select the sequence ... ... ... ... ... ... ... ... SEQ # (R5) to be edited
Select for editing.. ... ... ... ... ... ... ... ... ... SEQUFC (L5) to initialize the UFC for sequence programming
Select Insert ... ... ... ... ... ... ... ... ... ... ... :INS (U4)
Enter Waypoint number to br added .. ... nn / ENT
Repeat steps for each waypoint/OAP in the sequence

Insert Waypoint into a Sequence
Select waypoint data ... ... ... ... ... ... ... ... DATA (T5)
Select the sequence ... ... ... ... ... ... ... ... SEQ # (R5) to be edited
Select for editing.. ... ... ... ... ... ... ... ... ... SEQUFC (L5) to initialize the UFC for sequence programming
Select Insert ... ... ... ... ... ... ... ... ... ... ... :INS (U4)
Enter Waypoint left of insertion point . ... nn / ENT
Enter Waypoint to be inserted ... ... ... ... nn / ENT

Delete a Waypoint
Select waypoint data ... ... ... ... ... ... DATA (T5)
Select the sequence ... ... ... ... ... ... SEQ # (R5) to be edited
Select for editing.. ... ... ... ... ... ... ... SEQUFC (L5) to initialize the UFC for sequence programming
Select Delete .. ... ... ... ... ... ... ... ... :DEL (U5)
Enter Waypoint to be deleted . ... ... nn / ENT
All waypoints to the right of the deleted waypoint shift left one space left

Training Video:
Sequences: 2:00 to 3:00
Editing Sequences: 3:50 to 4:55

[VBF-12 Gosling]

09. WAYPOINT DATABASE & EDITING

Waypoint Database
The Waypoint Database of the Hornet has up to 60 Waypoints which can be connected together in up to three sequences each with up to 15 waypoints. Adding new waypoints or editing existing waypoints in the database.

To access the Waypoint Database:
Select the SUPT Page ... ... ... ... ... ... MENU (B3) Twice
Select Databases ... ... ... ... ... ... ... ... DATA (T5)
Select Waypoint Database . ... ... ... ... WYPT (B2) Box

Waypoint Data
The waypoint data page displays the selected waypoints detail in the top 3/4 and the waypoint wequence in the bottom 1/4. The waypoint detail displays:

• Waypoint Number (1 - 60)
• Latitude (N or S, Degrees, Minutes, Decimal Minutes - so 38 seconds will display as 53’
• Lonitude (E or W, Degrees, Minutes, Decimal Minutes - so 38 seconds will display as 53’
• Grid - I have yet to work out the code system for this
• Elevation - In meters or feet
• O/S RNG - Offset Range - Not Functional
• O/S BRG - Offset Bearing - Not Functional
• O/S GRID - Offset Grid - Not Functional
• O/S ELEV - Offset Elevation - Not Functional

Adding / Editing a Waypoint
On the HSI:
Select WPT ... ... ... ... ... ... ... Up Arrow (R2) & Down Arrow (R3) to select req’d wpt
Display waypoint data ... ... ... DATA (T5) - WYPT (T2) boxed
Edit waypoint data . ... ... ... ... UFC (R1)
On the UFC:
Enter Latitude . ... ... ... ... ... ... Select :POSN (U1) / Lat / ENT - Hemisphere, Degs, Mins, Secs
Enter Lonitude ... ... ... ... ... ... Enter Lon / ENT - Side of Greenwich Line, Degs, Mins, Secs
Check waypoint display .. ... ... Enter Lat & Lon will be in Degs Mins and Decimal Mins (ie 26 secs = 0.43)
Select Elevation Units . ... ... ...UFC Select :ELEV (U3) / Select :FEET (U1) or :MTRS (U2)
Enter Elevation ... ... ... ... ... ... Enter Elevation Above Mean Sea Level (AMSL) nnn / ENT
Check waypoint display . ... ... The loaded Elevation may be inaccurate by 1 unit or so.

- Trouble uploadeing, Stby

[VBF-12 Gosling]

N10 - DESIGNATION OF A WAYPOINT AS A TARGET

Description
Any waypoint can be allocated as a designated Target by selecting the waypoint and pressing the WPDSG (R4).[/b]

HSI Symbology
Diamond around dot - Designated Waypoint

HUD Symbology
Diamond in HUD - Designated Waypoint

Aircraft Setup
Ensure a waypoint is programmed
On DDI:
Select Waypoint ... ... ... ... ... ... Up & Dn Arrows On required Waypoint
Designate Waypoint . ... ... ... ... Select WPDSG (R4)
Ensure Waypoint is diamond boxed
On HUD:
Turn to Heading Caret
Identify Waypoint within Diamond
To undesignate the waypoint:
Undesignate Waypoint ... ... ... ... Select Undesgnate/Nose wheel steering Paddle
Confirm diamond box removed from waypoint

This waypoint can be used as a target for bombing etc.

[VBF-12 Gosling]

N11. TIME ON TARGET

Description
The F-18C navigation system is sufficiently accurate to allow accurate calculation of ground speed to allow overfly of a specific location at a designated time. This is called Time on Target (TOT).

For this the aircraft needs to be programmed with the appropriate waypoints including the Target (TGT) and an Initial Point (IP). The leg prior to and between the IP and TGT is where the Time on Target information will be presented. Normally an IP would be about 2 minutes away from the target and be something really obvious in the local area. However, with modern accurate GPS this no longer matters but it is very reassuring to have a clearly identifiable IP.

Aircraft Setup
As has been mentioned the aircraft must have the route waypoints programmed and entered into one of the three routes sequences in the correct order. It is recommended to have the Sequence running in AUTO (B5). Also, the sequence must be displayed to the HUD - SEQ (R5) boxed.
On DDI:
Display HSI ... ... ... ... ... ... ... ... ... ... MENU (B3) / SUPT (B3) / HSI (L4)
Display Waypoint Data .. ... ... ... ... ... DATA (T5) / SEQ (R5) boxed / AUTO (B5) boxed
Edit the Sequence ... ... ... ... ... ... ... SEQUFC (L5) boxed
On UFC:
Enter required Time on Target .. ... ... :TOT (U3) / HHMMSS ENT - Time in UTC (Zulu)
Enter required Groundspeed . ... ... ... :GSPD (U1) / nnn ENT - 500 Kts is good
Enter Target ... ... ... ... ... ... ... ... ... ... :TGT (U2) / w ENT - w = Waypoint number
On HSI Waypoint Data:
Check Settings ... ... ... ... ... ... ... ... ... HSI shows box around the waypoint and TOT bottom left, rime & groundspeed

HSI Symbology

• Box around TOT Waypoint in Sequence List
• TOT, Time & Groundspeed selected in bottom left
• Required Groundspeed in centre

HUD Symbology

• Ahead / Adrift Marker - Below Airspeed Indicator. Center is on speed, right is slow, left is fast. Don’t chase this when close to the waypoint

Flight Profile
Once the target waypoint and TOT details have been setup, the Required Groundspeed is shown in the centre of the HSI. Also, below the Airspeed Indicator of the HUD is the Ahead / Adrift (really its a Early / Late Caret, but we are in the Navy ) marker. This will move right if you are fast and ahead of time and left if you are slow and will arrive at your IP adrift of your chose time. So it is getting you to your IP on time to ensure the run from the IP to the TGT will be at 500kts groundspeed AND ensuring your arrive over your target at the chosen time.

Once approaching the IP waypoint ensure the next (Target) waypoint displays (AUTO) and keep the Ahead / Adrift Marker centred. Look for your target and attack as required.

I am hoping we will get to the point where we can attack a bombing target with 3 aircraft from three different angles and deliver the weapons (Hi drag munitions) onto the target from very low passes at 10sec intervals!!!

Training VideosL
Basics: 4:55 to End


More in depth:

[VBF-12 Gosling]

N12. WAYPOINT OFFSETS

... more to follow...

[VBF-12 Gosling]

N13. INSTRUMENT CARRIER LANDING SYSTEM (ICLS)

Reference:
CNATRA P-816 - CV Procedures - T-45C

Description
There are 3 methods of recovery to the carrier depending upon the weather conditions.

• CASE 1 - Case 1 is used during good weather (Vis >=5nm, Cloud Ceiling >=3000ft) and is an overhead join, a visual no comms pattern and a short final approach to trap
• CASE 2 - Case 2 is when the weather is not so good but a visual pattern is still possible (Vis >=5nm, Cloud Base >=1000ft) and for all night visual approaches. The approach is procedural made from a CASE 3 Hold astern of the ship to the Initials point where a visual pattern is conducted as is CASE 1. So it is CASE 3 procedure outside 10nm and CASE 1 procedure within
• CASE 3 - Case 3 is a fully instrument in weather less than for CASE 2 (VIS <5nm or Cloud Base <1000ft). It is approached from the same hold as CASE 2 to the Short final with a visual recovery in the last 3/4 nm to trap. This approach is further split into three types:
  • Mode 1 = ACLS. The Automatic Carrier Landing System requires a data link form the ship to the aircraft and correction signal to maintain the aircraft on ICLS are sent to the aircraft. This allows the aircraft to be recovered in very poor weather as teh landing is automatic as well. Mode 1A is an ACLS to a manual landing using the “Ball”
  • Mode 2 = ICLS. The Instrument Carrier Landing System requires the pilot to fly the Azimuth and Glideslope needles to a 3/4nm point before seeing and landing manually using the “Ball”
  • Mode 3 = Carrier Controlled Approach (CCA) requires a talk down from the ship to give corrections for the pilot to fly manually to aquiring the “Ball” and Landing visually

Aircraft Setup
On the DDI:
Ensure MOTHER’s TACAN is selected and boxed as above
Pass ICLS to the HUD ... ... ... ... ... ... ... ... ... ICLS (L2) boxed
CRS Switch ... ... ... ... ... ... ... ... ... ... ... ... ... Select until UFC displays :CSEL
On UFC:
Enter BRC .. ... ... ... ... ... ... ... ... ... ... ... ... ... nnn ENT

HSI Symbology
CRS Bar - Through the TACAN on BRC heading
CSEL nnn - Displays required BRC (Bottom RIght)

HUD Symbology
Azimuth Needle - Displays when astern of the carrier
Glideslope needle - Displays wIthin 6nm

Flight Profile
See DCS F-18 - CASE 3 - IF Recovery Procedure

Training Video

[VBF-12 Gosling]

N14 - TERRAIN AVOIDANCE WARNING SYSTEM (TAWS)

Description
The TAWS alerts the aircrew of a controlled flight into terrain (CFIT) condition during all mission phases. The system operates any time that the navigation mission computer (MC1) and TAMMAC digital mapping set (DMS) are functional. TAWS has been designed to eliminate false warnings, minimize nuisance warnings, and generate consistent aircrew response in all aircraft master modes. TAWS uses data from the following inputs: Air Data Computer (ADC), Flight Control Computer (FCC), Inertial Navigation System (INS), RADALT, GPS, and digital terrain elevation data (DTED). DTED resides in the DMS as part of TAMMAC and is used to provide the forward-prediction capability that protects against flight into rising terrain.

When a DMS is not installed in the aircraft or is not operational, protection from CFIT events is provided by the Ground Proximity Warning System (GPWS) which uses the RADALT, INS, and ADC, with the RADALT as the primary source of information for terrain.

Recovery Trajectories:

• Vertical Recovery Trajectory (VRT) is the standard GPWS-like recovery: roll to wings-level, if needed, and pull to recover
• Oblique Recovery Trajectory (ORT) assumes that you maintain the current bank angle and pull to recover (increase turn rate)

Aircraft Setup
TAWS automatically switched ON (TAWS boxed) on start up. However, it can be switched off as follows:
Select the HSI Display ... ... ... ... ... ... ... MENU (B3) / SUPT (B3) / HSI (L4)
Select DATA ... ... ... ... ... ... ... ... ... ... ... DATA (T5)
Select TAWS OFF .. ... ... ... ... ... ... ... ... A/C (T1) / TAWS (B5) Unboxed

HUD Symbology
VRT = Large Arrow pointing up the HUD pitch Ladder - If not wings level this will be accompanied with a “Roll Left (Right)” aural instruction. ROll level before pitching.
ORT = Large Arrow pointing up the aircraft axis

Audio Warnings
There are 5 audio warnings associated with the TAWS:

• ″Roll−Left...Roll−Left″
• ″Roll−Right.....Roll−Right″
• ″Pull−Up...Pull−Up″
• ″Power...Power″
• ″Check Gear″