Sharing data

This document covers the sharing of data in the Kamov Ka-50 with a focus on the transmission and reception from the A-10C.

It has been originally written for internal use, translated and then made public.

I want to thank the entire Fighter Combat Sims group and especially Alberto "Brontolo" for helping me in testing.

A special thanks goes to EinsteinEP for his essential help developing the chapter “Bearing and distance” and in the correction and review phase.


Summary

1. Introduction
• Preparing the ABRIS
• Different bearing types
• PRTz Datalink
• Locking a target

2. Sharing data: Ka-50 to Ka-50
• Saving a target with the PRTz
• Sharing data between Ka-50s
• Automatic ingress to target

3. Sharing data: Ka-50 to A-10
• Getting coordinates with the ABRIS
• Getting coordinates with the PVI-800
• Receiving coordinates

4. Bearing and distance
• Nine-Line
- Nine-Line example
• FCS “K-Line”
- Transmission example

5. Final considerations



1. Introduction

Ka-50s and A-10s are very different aircrafts. Just think that the Ka-50 is Russian and uses the metrical measurement system and the A-10 is American and uses the Imperial system. Knowing that, there should be no surprise when I tell you that there isn’t a way for sending and receiving data between these two aircraft directly. Therefore we have to find a measurement system supported by both of them.

The short paragraphs below are just a small reprise of concepts that you may have already learned. To deepen your understanding, read through the ED manuals.

Preparing the ABRIS
One of the instruments we are going to employ is the ABRIS, but first of all we have to match A-10’s unit of measurement. The ABRIS can represent lat/long coordinates in one of two ways:

• XXX°YY'ZZ" (degrees, minutes and seconds - ABRIS default)
• XXX°YY.YY' (degrees, minutes and decimals - PVI-800 default)

A-10s use the second representation mode hence we have to set the correct unit of measurement. To do this, go to the ABRIS setup, select the UNITS FSK, and change the setting (see the Black Shark manual, page 7-26).



Different bearing types
Ka-50s and A-10s represent bearings in two different methods: Ka-50 uses True Bearings while A-10 uses the Magnetic bearings. You can toggle the ABRIS between each methods in the Options menu, entry “Track/heading”.

PRTz Datalink
The PRTz is a very important part of a Ka-50’s avionics. This device allows sharing data directly to each Ka-50 in your flight. It is composed of three rows of buttons, from top to bottom:
• target type: Armor, SAM/AAA, Other, and Ingress point;
• recipient: select who will receive your data, from #1 to #4 or the whole flight;
• functions: erase the selected target from the memory, perform the automatic ingress to target, send or receive data.

Locking a target
First of all we have to spot a target in order to lock it. This task can be performed in many ways, exempli gratia:
• Put laser switch on STAND-BY position;
• Activate the HSM and position it over the target;
• Uncage the Shkval;
• Adjust the gate around the target;
• Press the Lock button.



2. Sharing data: Ka-50 to Ka-50

A Ka-50 flight is composed of up to four aircrafts. Each pilot is assigned a unique ID number from 1 to 4. You can see your wingmen (or your leader) and recognize them on the ABRIS by this number.
Assuming that you have already locked a target, you can now save it for your use or send its data to the rest of your flight.



Saving a target with the PRTz
Saving a target and making it appear on your ABRIS is very easy. Just select the correct target type button in the PRTz’s first row and press SEND/MEM.
E.g. if we have locked an enemy T-80, we will first select the armor target type, then press SEND/MEM. A diamond with a number (#1 for the first target) written into will appear in the ABRIS. This number is incremental, if you save another armoured target with the PRTz, it will appear as a diamond with a #2 in the middle.
This target representation will be later used to get its coordinates and send it to others (A-10s, for example). But we will delve into this aspect later.

Sharing data between Ka-50s
In order to send data about target you must select the recipient (from #1 to #4, or the whole flight), cycle between your saved targets by the corresponding target type button and then press “SEND/MEM”. The selected recipients will receive your data.
Now let’s see what happens if you are one of those recipients: some buttons on the PRTz will begin to flash (letting you understand who and what type of target you are about the receive), Betty will warn inviting you to take a look at the EKRAN and it will finally tell you that you have just received some data (“RECEIVE DL TARGET”). Press “SEND/MEM” to save, and the target will appear on your ABRIS. Quite easy, isn’t it?
Last important thing: the number written into target’s symbol couldn’t always be the same for the whole flight. E.g. if we have already saved an armoured target (target type #1, a diamond on the ABRIS) and your wingman will send you data about another one, you will see two diamonds on your ABRIS. The one we have saved before is the #1, and the one just received is the #2. But your wingman could have just one armoured target in his ABRIS, and it is identified by the #1. This means that our #2 is his #1 and vice-versa, and you don’t know that. So pay attention and try to avoid confusion!

Automatic ingress to target
This is a very useful function. It allows to release the Shkval directly on a target received or saved with the PRTz.
• select a saved or received target by its corresponding target type button;
• enable the AUTO TURN function (not mandatory but useful);
• put laser on STAND-BY;
• uncage the Shkval.
And your aircraft will magically turn and lock the target.



3. Sharing data: Ka-50 to A-10

There are two possible ways to get a target’s coordinates: with the ABRIS or the PVI-800. The first one is more precise (~20m), the second one is far less precise (~200m) but it’s faster.



Getting coordinates with the ABRIS
Before using this method you need to lock a target and save it into your PRTz, so it will appear in your ABRIS.
To get the coordinates of a target we will use the ABRIS in ERBL mode. To enter this mode, cycle with the 5th FSK, entering the NAV mode. Pressing this FSK enable the ERBL mode: a cross will appear and, below the map, you will find coordinates of the position under the cross as well as other data, like bearing and distance. As you have already imaged, you can now move the cross over the symbol of a target acquired with the PRTz and read its coordinates.
To move the cross use the right knob on the ABRIS. Press it to toggle from vertical and horizontal slew and vice-versa. To obtain the best result, use the Zoom in FSK.
This procedure is not very fast and requires a lot of attention, therefore it’s not a bad idea to recon a Battlefield Area, save your targets in the PRTz, move into a safe and covered position and only then communicate the coordinates.

Getting coordinates with the PVI-800
We’re now going to see how to save a target position and get its coordinates. This method is faster than the one which uses the ABRIS, but it’s less accurate.

First of all, we have to prepare the PVI-800:
• set the PVI mode in ‘EDIT’ with the PVI Master Mode knob;
• set the switch next to the PVI Master Mode knob (‘INU/UPDATE’) to the ‘INU’ position (“I-251V Shkval – Fly over INU update” - see the Black Shark manual, page 6-65);
• select the ‘NAV TGT’ button on the PVI-800.

A number will appear on the PVI-800. This number represents how many NAV TGT points are stored inside PVI-800’s memory. Now select a number, press the Shkval designate key (with the laser in STAND-BY position) and the coordinates of the position pointed by the Shkval will appear on the PVI-800. Now you can save this data by pressing the ‘ENTER’ key.
NAV TGT points saved with the PVI-800 are represented in the ABRIS by a rectangle with a number written into. Each number corresponds to the number assigned to each NAV TGT point saved.
A NAV TGT point can be assigned directly to a PRTz target, just select a target type (first row on the PRTz) and press ‘SEND/MEM’.
Just remember to restore the PVI-800 to previous settings, turning the PVI Master Mode knob on ‘OPER’ position, and the switch next to it in ‘UPDATE’ position.

Receiving coordinates
As you can read coordinates with the PVI-800, so you can enter coordinates with it.

The procedure is quite similar to the one used to get coordinates of a target locked with the Shkval:
• set the PVI mode in ‘EDIT’ with the PVI Master Mode knob;
• select the ‘NAV TGT’ button on the PVI-800;
• select a number, which will identify this NAV TGT point.

Now you can enter the coordinates. Remember to use the button 0 (zero) for North and Eest, and button 1 for South and West. When you have finished, press ‘ENTER’ to save. Again, restore the PVI Master Mode knob to its previous position.
NAV TGT points are represented by a squadre with a number in the middle (this number identifies the NAV TGT point). Therefore, pressing a number in the PVI-800 while in NAV TGT mode will select the corresponding point. Selected points will flash on the ABRIS.




4. Bearing and distance
Lat/long coordinates actually are not the only way to provide the location of a target to another aircraft. As you can see in the picture regarding the ERBL, both bearing and distance are displayed besides lat/long coordinates. However those data are referred to your position, which usually changes often. Fortunately we can choose a different reference point, pressing the “MARKER” FSK. This point can be, e.g. the Bullseye used by A-10s, previously communicated and inserted with the PVI-800 (as the picture below shows).
The “MARKER” function can be activated only when the ABRIS is in ERBL mode. First of all place the ERBL cross over the Bullseye or the reference point. Now press the “MARKER” FSK. The cross will turn in a triangle, a new one will appear and all you have to do is just move it over the target. Distance and bearing to target (as well as other data) are real-time calculated.

Providing bearing and distance can be useful sometimes, but is not an accurate method. Each step you follow adds an error, which increases considerably over long distances. Moreover, bullseye coordinates saved via PVI-800 aren’t precise and the approximation introduced rounding heading values can result in an error that can be calculated as:

Position_Error = Range * Bearing_Error [in radians]

Therefore ½ degree of bearing measurement error would result in ~8.7m position error per kilometer of range from the reference point.

Moreover remember that Ka-50s use True bearing, but A-10s use Magnetic bearing. Therefore you have to subtract the magnetic declination value (MVR) every time you provide a bearing. Also remember that default unit of measurement for distance is in metric system (km).

However bearings and distance combination can be useful, especially to provide an approximated indication of target’s position. For this purpose a distinctive geographical element close to the target can be efficiently used as the reference point.



Nine-Line
The 9-line is a standardized procedure used by JTAC personnel to send the necessary target parameters to attack aircraft pilots. This format can’t be applied by Ka-50s as it comes, but its a good starting point to develop your own procedure by mutual agreement with the A-10 pilots which fly with you.
The only problem you will find using the 9-line is the target location coordinates which comes in a format that can’t be provided by Ka-50s. You can use the latlong format, but it takes more time and makes bearing/distance redundant.
You have to pay attention to measurement units also. ABRIS provides data in the metric format by default, hence you have to convert distance and elevation to the appropriate measurement unit.

Nine-Line example


JTAC: “Tank 21, this is Groundhog 11, type 1 in effect, call when ready for 9-line.”
Attack Aircraft: “Groundhog 11, Tank 21 ready to copy.”
JTAC:
“MAZDA
010
9.9
450
Eight enemy tanks heading south on a north-south dirt road
NB 865427
None
South 1200 meters
Egress east to CHEVY
Final attack heading 320 to 030”
Attack Aircraft: “450, NB 865427, final heading 320 to 030”
JTAC: “Read back correct, report 5 miles east of target.”
Attack Aircraft: “Roger, IP inbound.”

As already said, the 9-line is a good starting point to develop your own procedure. After several tests we have created a new format that fits well with our needs, balancing the completeness of the information with the easiness of the transmission.

FCS “K-Line”
The K-Line is the Fighter Combat Sims standard procedure for sending a target’s coordinates from Ka-50s to A-10s. It is composed by six “lines” and it is based on latlong coordinates instead of bearing/distance.

The AFAC must provide:
• Target type: “soft”, “medium” or “hard”, basing on the “hardest” target (e.g. a T-80).
• Target elevation: target elevation in feet above mean sea level. Reported only if relevant;
• Latlong coordinates: target’s coordinates in xxx°yy.zz’ format;
• Location of friendlies: distance in meters between the target and friendly units. Reported only if there are friendlies within 500m from the target;
• Ingress: ingress direction;
• Egress: egress direction;

The attack aircraft will readback:
• Latlong coordinates;
• Ingress direction;
• Egress direction.

Transmission example

Notes:
• #1, #2, #3, #4 are not contiguous in time. There can be a time slice between each comm;
• #5, #6 data type (type, altitude, etc) can be omitted. Here are reported for clearness.

As you can see we have cut some parts of the nine line. The reason is simple: provide only the most important data to the pilot. For example, bad weather can drastically reduce the visibility, broken LOS can cause breakdowns in communications (if you are using TARS) or the ground terrain can be very rugged and can hide enemy threats. Taking into account all these factors can be very hard, therefore is a good idea to force the pilot to remember as few data as possible.

However, with the k-line CAS pilot has enough elements to:
• Decide which weapon he will use, basing on the target type and the nearness of friendlies;
• Define an approach to the target evaluating the suggested ingress route;
• Define a safe route to leave the area thanks to the suggested egress direction.



Final considerations
Even if A-10s and Ka-50s haven’t a common system which should allow them to share data directly, there is more than a way to move around the problem. Summing up, the Ka-50 can use:
• ABRIS to provide lat/long coordinates;
• ABRIS to provide distance and bearing;
• PVI-800 to provide lat/long coordinates;
All you have to do is choose the most performing way, basing your evaluation on your task and the situation around you.



Info:

This is beautiful! And it should be a sticky.

wow, very nice job my friend !

Moved to the new FAQs and References section. Well done, red!

It should be added that the Ka-50 datalink requires that all participants have functioning VHF2 radios tuned to the same frequency for datalink functions.