Lost comm procedures in the NAT HLA (or when you’re trying to get into the NAT HLA) are a complex and confusing thing, so here is our “Natter on the NAT” – a recap on what to do when nobody wants to talk to you.

You aircraft has lost everything it uses to communicate.

The likelihood of every communication system you have breaking all at once is fairly minimal, and given the equipment requirements to enter the NAT HLA, you are going to have more than just VHF onboard. You will also have HF, datalink, probably SATCOM…

But if it does happen (maybe a freak bolt of mega lightning or something) then the first thing to do is still try each system, including back up boxes, and your headset for that matter.

Still no luck? Don’t panic. While you can’t hear anyone, or talk to anyone, they can all still hear and talk to each other. So you are the only uncoordinated thing out there right now. First up, let ATC know by squawking 7600.

The next thing to do depends on where in the NAT you are.

Already in it? Great, simple. You already have a clearance and you already know where you are going, so carry on as you are, transmit blind, and once you exit follow the lost comm procedures for the place you are entering.

Not in it, but have a clearance? This is up to you really. You have your clearance (and have confirmed it) so ATC know that you know that they know that you know what you are cleared to do. So if you want to stick to in and head on in you can, but you are going to have to maintain your speed, level etc all the way through. And if you have a weather issue or an emergency you are also going to be on your own.

No clearance yet? This one is a bit tougher. It probably isn’t the best plan to head in (following your flight planned route), especially if you are heading into Shanwick. Shanwick have diversion procedures in place to take you to Shannon and the best idea might be to head there and get yourself fixed.

The exact wording is “it is strongly recommended that a pilot experiencing communications failure whilst still in SHANNON FIR/UIR/SOTA/NOTA does not enter SHANWICK Oceanic Control Area”.

The Irish AIP have the procedures for comms failure if planning on entering and they are worth a read. They have a pretty handy summary of what to do for Shanwick in there.

You have lost HF

If you’re already in, there isn’t much you can do. Stick to your clearance and keep in contact on CPDLC. Remember, HF frequencies are pretty rubbish at the best of times so if you discovered the failure while trying to make an HF call, then try a different frequency.

Lower ones work better at night, higher ones by day, and always try the middle ones for good measure. Have a quick glance at space weather too because if there are geomagnetic storms forecast it could be there is a general HF blackout going on that is affecting everyone.

Collins Aerospace publish a daily list of HF frequency assignments for their side (the US side) of the North Atlantic and you can find them here.  Worth a look before you fly, if you’re going to be in the US North Atlantic area.

The Comms requirements changed a bit in February 2021, and basically, what they say, is that you need two long-range comms systems if routing anywhere outride VHF coverage. One of these has to be HF.

Here is a particularly horrible picture of where VHF has got you covered.

You can route through if your HF was already broken and you told ATC in advance (Item 18 on the flight plan) and they gave you the thumbs up, but if you are heading there and it goes suddenly before entry then you are going to need to talk to ATC.

Shanwick OCA needs HF, no exceptions (not even the Blue Spruce routes that fall within the Shackwick OCA) so don’t go diverting immediately but do get talking (on whatever else you have available) to sort it out before you enter.

We might as well cover HF blackouts while we’re here.

These happen when space weather happens. They aren’t super common and they are usually minor (lasting 10 minutes or less). But when they do happen, everyone can lose HF, including ATC.

You probably should make position reports on 123.45 to be on the safe side because there might be no coordination between traffic and ATC for the period of the blackout. Keep trying different methods to get hold of ATC as well (but don’t get all crazy at them though – they will be busy and will contact you when able).

Now, because coordination between ATC and everyone else is an issue, they actually don’t want everyone diverting all over the place, so stick with your clearances. The big point here is – if you don’t have a NAT clearance yet, you need to stick to your DOMESTIC clearance. That means you have to stick with what you were most recently told to do, not what you filed for on your flight plan.

Datalink problems.

So your texting system is on the blink? Unfortunately, the Datalink Mandate is in force now so you need this to enter. If you ask ATC nicely (and have everything else working) they might still let you in.  

You don’t need it if you are north of 80N, in NYC Oceanic, on Tango 9 or 290 route, or in the ‘surveillance airspace’ over Iceland/Greenland. So if you can re-route via any of this, that might be a good plan. Otherwise you do also have the option of flying above or below the NAT HLA (so below FL290 or above FL410) if your aircraft (and your fuel) can do that.

Remember, datalink uses CPDLC and ADS-C so if either of them is broken, your datalink probably is as well.

SATCOM

Most datalink systems also require SATCOM – so while you don’t need it to use it, if your aircraft needs it for the Datalink to work, then what we said above applies.

Let’s talk ATC – Strikes.

An ATC strike is *usually notified in advance. The chances of them walking out without warning is fairly remote. So if you know about it beforehand, plan accordingly. If it happens while you’re there, treat it as an ATC Zero event.

ATC Zero.

There is no-one out there. Maybe they had to evacuate? There was some sort of emergency or major technical issue that’s has taken down an entire ATC provider? Occasionally it is Notam-ed, but in that case you won’t have been given clearance to head through, so we are talking those unforeseen sudden zero events.

Each region has its own contingency procedures which you can find in their AIP, or better still in NAT Doc 006, which was also updated in Feb 2021.

These routes are really for when big stuff happens – the entire ATC for a sector is evacuated for example. In most cases, other units will try and manage control as best they are able, but it will be fairly limited.

So, if you’re already inside, continue and start trying to make contact with the next sector (as they will hopefully be managing control as much as they can). If it is a big ATC zero event you are probably going to have to follow the contingency routes to exit the NAT HLA (rather than your clearance) but this will be ‘activated’ by whichever ATC is taking over control.

If you already have your clearance to enter you can, and you can transmit position reports on 123.45, but it is not really advisable. The best plan is to organise a re-routing.

If you don’t already have a clearance then you aren’t going to be able to enter the ATC zero bit and you will need to plan a re-route around the affected sector.

Feeling the need to read more?

Here are some handy links to things on the subject.

Changes to NAT Doc 006 – our blog post summarising what these were.

The Irish AIP (again) in case you missed the link earlier.

The GOLD Manual (2017 edition) – for all your Datalink info.

Opsgroup Member?

Then click here to download our handy little Comms Issues on the NAT “Opsicle” – a refreshing bit of ops info, just for members.

If you’re not an OPSGROUP member, but you’d like to be, you can join here.

Communications in aviation are meant to be standard. Everyone speaking the same language, in the same way. Alas, alack, and unglücklicherweise, we all know this ain’t always the case. Some areas have their own ways of doing things, others just seem to be difficult on purpose. 

So here is a rundown of some of the places you might want to listen out for on your international adventures.

Er-can’t hear you

If you are routing between the Ankara FIR and Nicosia FIR then you are going to need to look out for Ercan Control.

Ercan want to control an area over Northern Cyprus, but ICAO don’t recognise their authority. So you’ll probably have to call each centre separately as they don’t like to talk to each other directly.

To make matters worse, you need to coordinate with Ankara and Nicosia ten minutes before reaching their respective FIR boundaries, which often means relaying via Ercan because Ankara can’t hear you.

The waypoints to look out for are TOMBI (125.5) or DOREN or VESAR (126.3). Call the next FIR 10 minutes before you reach these.

Southbound is the messiest – make sure you keep following the instructions from Ankara, (or relayed by Ercan 126.7/ 126.9) until you reach these points. Once you do, there is a chance they will tell you you are now under Ercan control, which you should politely acknowledge and then ignore.

At this point, talk to Nicosia, do what they instruct, and once that’s all sorted, then call Ercan as a courtesy to let them know what you’re doing.

In Brief:

• North of TOMBI/DOREN/VESAR = Ankara controls you.
• South of TOMBI/DOREN/VESAR = Nicosia controls you.

You might have to relay info to Ankara via Ercan, and you might have to tell Ercan what you’re doing in Nicosia airspace, but remember – Ercan don’t have control!

Asia old politics

This is just a plain old case of political rivals. Pakistan and India don’t like talking to each other, which often means they won’t hand over to each other between their airspace. So be sure to have the frequency ready – and a call to let the previous know that you’re changing over at boundary is a good idea.

Pakistan Air Defence need to hear from you at least 15 minutes before you enter their airspace, and often ask for your ADC number.

There are different frequencies depending on where you’re entering, but the main ones are Karachi 128.350 and Lahore 124.100.

A run in with Iran

Tehran are another strict “call us first” airspace, and they take it pretty seriously if you don’t get in touch.

The Air Defence want a 10 minutes heads-up. If you are departing out of a UAE airport, this probably means calling as soon as you pass 10,000ft.

ADIZ can be found on 127.900 and they’re going to want to hear:

• Who you are
• Where you are going 
• When you’ll be reaching them 
• What altitude you reckon you’ll be at when you do 
• Your squawk code

After relaying all this info to them you will probably get a cursory “call xxx”, and that’s that.

IFBPolite

Over some parts of Africa, there are more giraffes than there is radar coverage. Big swathes of Africa have little control, so you are going to need to do some in-flight broadcasting here.

It might sound like a chore, but numerous heavy and super jets route through here, and not hitting their wake is probably one the best reasons to work out where they are and when. (And if you’re one of the big ‘uns, then thinking of the little ones is a nice thing to do as well!)

Generally, one IFBP seems to wake everyone else up and triggers a bunch of others, and then you can get a good idea of where everyone is routing.

More info can be found in IATA’s IFBP document, but here is a little IFBP script in case you need it:

Mumbai, Mumbai HF etiquette

The HF radio over Mumbai airspace is the bane of many a pilot’s long-haul life. It often seems to defy all logic of night versus day frequencies, and is usually a trial and error situation to try and work out which one is working.

We found 10018 / 8879 / 5658 tend to have the best reception.

You will know when you do find the golden frequency, because you will hear the ear-aching scratchy hissing, overlaid with a dozen airplanes all calling at once and not listening out for each other.

So try to avoid talking over another aircraft, but be ready with your finger on the mic trigger for when a tiny pause occurs and you get your call in. The radio is rarely good at the best of times so headsets are recommended. 

Mumbai also have CPDLC. The logon is VABF. But they only use it for specific routes. If you cannot get a hold of them, give their SATCOM a go on 441901 or 441920.

The lingo Down Under

Australia are like teenagers – happy to text, but rarely do they actually want to talk to you. Nearly all of the Upper Preferred Routes in Australian airspace use CPDLC.  Which is actually great. But only if you’ve got it, and only if you get it right (you do need RNP10 and ADS-C/CPDLC to route along these).

You can logon to YMMM/Melbourne or YBBB/Brisbane (15-45 minutes before) and when you enter, they like to receive a position report. From then on its very straightforward.

A593: The Akara Corridor

There’s a bit of airspace off the coast from ZSPD/Shanghai known as the ‘Akara Corridor’, where different ATC centres are responsible for the control of aircraft at various different crossing points. South Korea (RKRR/Incheon) controls north-south flights here, while Japan (RJJJ/Fukuoka) controls east-west flights.

This area has always been unusual in that more than one center has had responsibility for controlling aircraft at different waypoints.

But on 11 Jan, 2021, ATC authorities in Japan, China and South Korea agreed to implement a proposal from ICAO regarding ATC management in this area – so from 25 March, 2021, South Korea will control all flights in this area.

Wild comms in Idlewild (JFK)

No briefing on ‘The Comms Hot-Spots to Look Out For’ would be complete without a mention of KJFK/New York controllers.

Granted, this is a busy airport, in busy airspace, but operating into JFK is not for the faint-hearted. Controllers speak fast, only say what they need to say once, and get very mean very fast if you mess up. 

Expect multiple runway changes for landing, and on departure keep an eye on the ATIS because they won’t always tell you if your departure runway changes, you’ll just find out on the taxi.

There are quite specific when’s and where’s to call on the ground as well – once clear of the runway, check in with ground, but also apron to find out your gate and entry to the apron, because ground will probably want to know this, and sometimes the two don’t seem to talk to each other.

Lost Comms

ICAO Doc 4444 contains the standard lost comms procedure. Some countries have their own versions too.

If you’re in IMC:

• Maintain last assigned speed and level (or minimum flight altitude if higher) for 20 minutes after the point you failed to report at.
• Then follow your flight plan.

If you’re in IMC and in an area with ATS surveillance:

• Maintain your last assigned clearance (minimum flight altitude if higher) for 7 minutes. The 7 minutes runs from when you first reach the last assigned altitude (because you lost your comms in the climb), from when you set 7600 (because you realised you’d lost comms while cruising), or from when you were unable to report at a compulsory point (you tried and it didn’t work because your comms aren’t working…)
• Then follow your flight plan.