SELCAL Feature Inoperable

[Mark Hubbert 1054583]

This post is intended primarily for Oceanic Controllers. It was recently noted during training that the SELCAL feature was not functioning for VPilot Users who were displaying a SELCAL code. Via PM on several occasions it was confirmed that the pilot did not receive the SELCAL notification and that they were using VPilot. I am not certain whether this issue is isolotated to just VPilot or if there is another issue elesewhere. I am posting this thread at the request of Ross whom I had previously notified.

[Josh Glottmann]

I've had success with SELCAL (with vPilot) while on Ganwick.

[Ross Carlson]

Mark, any idea if they were using vPilot 1.0 or 2.0?

[Joshua Black]

Make sure that when you connect, you actually insert a SELCAL. (The connect window has Callsign, Aircraft type, and SELCAL) Simply having a SELCAL in your remarks section (IE SEL/ABCD) in your flightplan won't be sufficient. I learned this a short while ago after wondering why it wasn't working as well.

 

Speaking of which, Ross. Would it be possible to implement a feature that allows the above to be done? I frequently prefile my flightplan and include the SELCAL in the remarks section, but completely forget to add it when I connect. Is there a way for the server to automatically retrieve the SELCAL for pilots based on what they have in their flightplan? When I used squawkbox, this was possible. Plus I was able to hear other pilot's SELCAL, but it seems like vPilot only has a "SELCAL Received" (or similar) message show up. Not even the tones.

[Ross Carlson]

I frequently prefile my flightplan and include the SELCAL in the remarks section, but completely forget to add it when I connect.

 

Yeah, I can have it look for a SelCal code in either the connect box or in the remarks. Note that putting a value in the connect box automatically inserts it into the remarks when you file. So if you put one code in the remarks, and then deliberately change the code in the connect window, the code from the connect window will take precedence. And vice-versa ... if you connect with one code, it will insert it into the remarks in the flight plan window. If you subsequently open the flight plan window and change the code in the remarks and file, the code you enter in the remarks will take precedence.

 

Is there a way for the server to automatically retrieve the SELCAL for pilots based on what they have in their flightplan?

 

Note that the server is not involved here at all. It knows nothing about SelCal codes.

 

When I used squawkbox, this was possible. Plus I was able to hear other pilot's SELCAL, but it seems like vPilot only has a "SELCAL Received" (or similar) message show up. Not even the tones.

 

vPilot doesn't simulate the actual tones being sent over the radio. It only simulates the notification sound that you hear on the flight deck when YOUR tones are detected on the HF channel. I'm not sure why Squawkbox would have simulated the actual tones playing, especially for other aircraft, since, as I understand it, the idea is that the pilot would have the HF radio turned all the way down anyway, so he doesn't have to listen to the HF static all the way across the ocean. All he would hear is the SelCal notification sound when his aircraft's SelCal tones are detected by the radio circuitry. That notification sound is not the same thing as the SelCal tones.

[Mark Richards]

vPilot doesn't simulate the actual tones being sent over the radio. It only simulates the notification sound that you hear on the flight deck when YOUR tones are detected on the HF channel. I'm not sure why Squawkbox would have simulated the actual tones playing, especially for other aircraft, since, as I understand it, the idea is that the pilot would have the HF radio turned all the way down anyway, so he doesn't have to listen to the HF static all the way across the ocean. All he would hear is the SelCal notification sound when his aircraft's SelCal tones are detected by the radio circuitry. That notification sound is not the same thing as the SelCal tones.

Hi Ross

 

If the HF is not muted, you hear the SELCAL tones for all aircraft and the alert tones for your aircraft when it decodes the tones to match your code.

 

There are some quite strict rules around the tones and this is from an article I wrote some years ago (http://www.vatnz.net/pilots/pilot-faq/what-selcal/):

 

The Selcal is made up of two pair of tones, the first pair being transmitted for approximately 1 second, with the second pair transmitted for the same duration following a 0.2 second pause. The individual tone frequencies are designated by letters A - S excluding the letters "I" and "O". A typical Selcal code is AB-CD, which indicates that the frequencies designated by letters "A" and "B" would sent followed by the frequencies designated by letters "C" and "D". Duplicate letters are not permitted in either pair, since simultaneous transmission of two tones of the same frequency would not be distinguishable by the aircrafts Selcal decoder. Also, the same tone is nor permitted to be used in both the first and second pair. Each two-letter pair must have the first letter lower in the alphabet than the second, i.e. a code could be AB not BA.

 

Selcal codes have been in use on aircraft since around the late 1960's and are still in use and still being issued today.

 

Selcal codes are made up of 4 letters which consist of two two-letter pairs. A typical selcal code would be AB-CD or PQ-RS. Each letter represents a radio frequency :

 

A = 312.6 Hz

B = 346.7 Hz

C = 384.6 Hz

D = 426.6 Hz

E = 473.2 Hz

F = 524.8 Hz

G = 582.1 Hz

H = 645.7 Hz

J = 716.1 Hz

K = 794.3 Hz

L = 881.0 Hz

M = 977.2 Hz

P = 1083.9 Hz

Q = 1202.3 Hz

R = 1333.5 Hz

S = 1479.1 Hz

 

The letters 'I', 'N', 'O' and anything after the letter 'S' are not used.

 

I have noticed that it appears that vPilot is not necessarily strict to those rules, allowing all combinations and all letters.

 

The important rules are:

 

• Duplicate letters are not permitted in either pair
• The same tone is nor permitted to be used in both the first and second pair
• Each two-letter pair must have the first letter lower in the alphabet than the second
• The letters 'I', 'N', 'O' and anything after the letter 'S' are not used

 

Of course I stand to be corrected but certainly had pilots respond when I SELCAL them when their SELCAL code doesn't meet the requirements and they're using vPilot.

 

Another request would for consideration would be for a pilot to be able to enter the SELCAL code in their connection box without the hyphen.

[Ross Carlson]

Right, vPilot doesn't enforce the validity of the code, just like it doesn't enforce the validity of their callsign/tail number, or the flight plan, etc.

[Mark Richards]

Right, vPilot doesn't enforce the validity of the code, just like it doesn't enforce the validity of their callsign/tail number, or the flight plan, etc.

Worth asking.

[Ross Carlson]

The latest release of vPilot 2 (version 2.0.7, still in open beta) will now fetch your flight plan upon connection to the network and extract any SelCal code it finds in the remarks. It will only use that code if you left the SelCal code box on the connect window blank.

 

Also, if you manually enter SEL/XXXX in the flight plan window, that code will take precedence over any code entered in the Connect window or extracted from a prefiled plan fetched from the server upon connection to the network.

[Joshua Black]

Thanks, Ross! This is awesome.

[Josh Glottmann]

vPilot doesn't simulate the actual tones being sent over the radio. It only simulates the notification sound that you hear on the flight deck when YOUR tones are detected on the HF channel. I'm not sure why Squawkbox would have simulated the actual tones playing, especially for other aircraft, since, as I understand it, the idea is that the pilot would have the HF radio turned all the way down anyway, so he doesn't have to listen to the HF static all the way across the ocean. All he would hear is the SelCal notification sound when his aircraft's SelCal tones are detected by the radio circuitry. That notification sound is not the same thing as the SelCal tones.

Just a clarification for CTP, does SELCAL still broadcast at an audible tone if you have the volume turned down all the way (in the vPilot settings)?

Also, do you need to be connected to the same channel that a SELCAL was sent on (I thought I read somewhere that with vPilot or maybe SB, you didn't have to actually be on the frequency to hear a SELCAL alert).

[Lindsey Wiebe 1101951]

The latest release of vPilot 2 (version 2.0.7, still in open beta) will now fetch your flight plan upon connection to the network

 

This..... is.... awesome!

[Ross Carlson]

Just a clarification for CTP, does SELCAL still broadcast at an audible tone if you have the volume turned down all the way (in the vPilot settings)?

 

Yes, the volume control only affects voice comms. The SelCal tone is played through your default windows audio device and it will use your system volume level.

 

Also, do you need to be connected to the same channel that a SELCAL was sent on (I thought I read somewhere that with vPilot or maybe SB, you didn't have to actually be on the frequency to hear a SELCAL alert).

 

Yes, one of your COM radios must be receiving on the channel on which the SelCal message was sent. (As I understand it, that's how it works in the real world ... the SelCal tones are transmitted on the HF radio frequency.)