{"id":19209,"date":"2022-07-19T06:37:51","date_gmt":"2022-07-19T10:37:51","guid":{"rendered":"https:\/\/ops.group\/blog\/?p=19209"},"modified":"2022-07-20T09:34:21","modified_gmt":"2022-07-20T13:34:21","slug":"no-selcal-on-the-nat","status":"publish","type":"post","link":"https:\/\/ops.group\/blog\/no-selcal-on-the-nat\/","title":{"rendered":"No SELCAL On The NAT?"},"content":{"rendered":"

ICAO are hurriedly upgrading<\/a> the SELCAL<\/strong> system to allow for new codes. There\u2019s only a finite number of them available, and double ups are becoming are a problem. The potential for more than one aircraft to receive the same call in the same airspace is cause for concern.<\/p>\n

ICAO have been onto it for some time, and on November 3 there is a soft deadline for Air Navigation Service Providers (ANSPs) to upgrade their ground equipment to communicate with the new codes.<\/p>\n

But there is a problem<\/strong> on the NAT. Most of the ANSPs won\u2019t be ready in time. Which means if an aircraft has one of the new codes, for up to six months they will not have SELCAL when crossing the pond.<\/p>\n

Here\u2019s a quick rundown of why, and what the impact will be.<\/p>\n

SELCAL 101<\/h4>\n

If you are one of the few who already know what ’32-tone\u2019 SELCAL<\/strong> is, top marks and feel free to skip this part.<\/p>\n

If you don\u2019t, fear not. This ain’t no radio shack, but a little bit of tech stuff will help here. All you need to know is the alphabet and how to count to ten. Chances are if you\u2019re flying a plane, you already have that covered. Let me explain.<\/p>\n

Unless you actually like the soothing sounds of static for hours on end, or distorted mumblings from halfway across the globe, chances are you have heard of Selective Calling (SELCAL). It does the listening, so we don\u2019t have to.<\/p>\n

In a nutshell it is a signaling system that lets us know via HF or VHF when ATC is trying to get a hold of us<\/strong>, so we don\u2019t need to listen out all the time.<\/p>\n

Here\u2019s<\/strong> how it works.<\/strong> On the ground a SELCAL encoder transmits four audio tones at a time. Each tone is assigned a letter. When the four tones correspond to your aircraft\u2019s four-letter code, a decoder in your avionics hears it and triggers a SELCAL with a noise and flashing light. That\u2019s your cue to call ATC back. Simple.<\/p>\n

Enter the problem. Until now, only 16 letters (and therefore tones) have been available. That means there are just shy of 11,000 codes for aircraft to use. And so far, 37,000 have been allocated. Which means double ups.<\/strong> And the problem isn\u2019t going away.<\/p>\n

There is an increasing risk that multiple aircraft in the same airspace may receive the same SELCAL, and that could spell danger<\/strong>. ICAO knows that, and so they’re\u00a0adding 16 new tones (comprised of letters and numbers). That will bring the total to 32. And voila, \u201832-tone\u2019 SELCAL.<\/p>\n

This will create almost a quarter of a million unique code options and will cut the problem off at the knees.<\/p>\n

\"\"<\/strong>But there’s a problem on the NAT…<\/h4>\n

On the ground, ANSPs need to upgrade their SELCAL encoders to include the new tones. ICAO has set them a target of November 3 to get it done.<\/p>\n

However, three of the five ANSPs covering the NAT region (Gander, Shanwick and Santa Maria) have already indicated they won\u2019t be ready until at least Spring next year. In the interim, they won\u2019t be able to issue SELCALs<\/strong> to aircraft featuring the new codes (ones that contain\u00a0T-Z or 1-9).<\/p>\n

It\u2019s not clear yet how many operators this will affect, so Nav Canada has reached out looking for more info.<\/p>\n

They want to hear from you if:<\/p>\n