Question for 8.33 rules knowItAll

[piperboy84]

Looking at a panel reconfigure, the COM 1 is a 430 so has the 8.33 spacing, the COM 2 is a SL 30 which doesn’t. I understand there as some new rules on channel spacing. Am I good to go legally with just one radio being 8:33 or do I have to change the other one out for 8.33 too

[Jan Olieslagers]

Not claiming to know all, not by a long way. But as I read on various forums, there is one single EASA directive which the various countries interpret in their various ways. I have a vague memory of one CAA insisting both radios should "do" 8,33 but were refuted. No guarantees, though.

All this under the assumption you mean EASA-land, which in the future may or may not include UK. Outside EASA I have not the slightest idea, and am not the slightest bit interested.

[Crash one]

I'm under the impression that if it was there you can leave it there as long as you don't use it to talk to someone!

[Prop swinger]

CAA:From 1 January 2018 if you need to communicate on an 8.33 kHz channel you will need to use an 8.33 kHz capable radio In practice, you can only continue to fly with just a 25 kHz radio if throughout your entire flight you only need to communicate on 25 kHz frequencies.From the CAA website (http://www.caa.co.uk/General-aviation/Aircraft-ownership-and-maintenance/8-33-kHz-radios/).

[bookworm]

Looking at a panel reconfigure, the COM 1 is a 430 so has the 8.33 spacing, the COM 2 is a SL 30 which doesn’t. I understand there as some new rules on channel spacing. Am I good to go legally with just one radio being 8:33 or do I have to change the other one out for 8.33 too

Any required COM radio must be 8.33 capable. Any surplus to the required minimum need not be, but must not be used to transmit on 8.33 channels. For non-commercial VFR in the UK, the requirement is for one COM radio.

There's a strong incentive in the UK for airfields to convert their frequencies to 8.33, as the licence fee is about 1/3 of that for a 25 kHz channel. So you may find that, if you're used to a 2 COM-box operation, you'll want to convert the second to 8.33 sooner rather than later for practical reasons.

[Curlytips]

PB84, leave the SL40 in place so you can use the nav functions, but you need to placard the com side "for emergency use only". Effectively you are only supposed to use it for 121.5 and a couple of other frequencies since Jan 1st. Have done same with my KX155 so that I still have a glideslope.

[piperboy84]

PB84, leave the SL40 in place so you can use the nav functions, but you need to placard the com side "for emergency use only". Effectively you are only supposed to use it for 121.5 and a couple of other frequencies since Jan 1st. Have done same with my KX155 so that I still have a glideslope.

I actually have the following units in the Maule I crashed

https://www.valavionics.com/ins-429.html

http://www.ps-engineering.com/PAR200.shtml

So if I pull out the old audio panel (PMA 7000) and install the PAR200 I can pull the Sl30 out use the stand alone Val429 for the NAV 2 VOR/GS and because the PAR200 has a buildin 8.33 I pick up some shelf space with the Sl30 gone to properly install my VFR Garmin Aera 660 this sticks up above the glare shield about the same thickness as the SL30. So it’ll look like a custom fit ( see vid https://youtu.be/i80m-rVZWRE). Granted it’s a whole bunch of rewiring but worth it

[mothminor]

For non-commercial VFR in the UK, the requirement is for one COM radio.

Since when is it a requirement to carry a radio at all?

[Piper.Classique]

Since never, unless of course you want to enter controlled airspace. And while international travel is not actually impossible without doing so, it is very very difficult.
So, local bimble nordo, yes, fine. More than that means radio and transponder or some very convoluted routes.

[Jan Olieslagers]

More than that means radio and transponder or some very convoluted routes.

Radio: yes. Though I know some... who have ... at some time ... :) You may be very sure there is a fair amount of microlight traffic between BE and FR with no radio at all, or stand-by listening at best. I'll not say from which BE field instructors would routinely take their pupils to Maubeuge for touch and go's on the hard runway - nice complicated airspace with gliders and paradrop but never a syllable on the radio...

Transponder: not necessarily. I have flown from BE to Germany and France with no transponder, no issues. Though Langen Information audibly raised an eyebrow :) "Oscar Oscar ... , confirm negative transponder?" "Langen Information, I SAY AGAIN, negative transponder, Oscar, Oscar, ... " after which the lady came with a very sensible and workable solution.

[Jim59]

Since never, unless of course you want to enter controlled airspace.

Ah, but since this thread is addressed to 'rules knowItAlls', have you read the definition of controlled airspace in Schedule 1 to the The Air Navigation Order 2016? It says: ""Controlled airspace” means airspace which has been notified as Class A airspace, Class B airspace, Class C airspace, Class D airspace, Class E airspace, Class F airspace or Class G airspace;"

After checking that reference you may want to read ORS4 No. 1238 - General Exemption E 4536 which is valid to 30th September.

[ShyTorque]

The CAA have recently given a temporary dispensation:

8.33 kHz radios | UK Civil Aviation Authority (http://www.caa.co.uk/General-aviation/Aircraft-ownership-and-maintenance/8-33-kHz-radios/)

[Jan Olieslagers]

"Controlled airspace” means airspace which has been notified as Class A airspace, Class B airspace, Class C airspace, Class D airspace, Class E airspace, Class F airspace or Class G airspace;"

I'd like to know what they then classify as "uncontrolled airspace".

[Sam Rutherford]

Well, everything else. Obvious, innit?

Probably only accessible to US and Shuttle pilots though...

[Sam Rutherford]

Unless you're overhead Australia:

"Class G is used wherever other classes are not..."

I hope the Space station is 8.33 compliant...

[Crash one]

I think I read somewhere once that all airspace above 35000ft over the UK is class A.
I may be wrong, I usually am.
At the time I thought, this makes it illegal to leave the planet without an IR.

[Heston]

https://www.pprune.org/spectators-balcony-spotters-corner/169276-how-high-does-controlled-airspace-go.html

[Piper.Classique]

Well, I did once fly from Poland to home in France Nordo (radio died en route). It involved a fair number of grovelling phone calls. No transponder, either.

[Gault]

have you read the definition of controlled airspace in Schedule 1 to the The Air Navigation Order 2016? It says: ""Controlled airspace” means airspace which has been notified as Class A airspace, Class B airspace, Class C airspace, Class D airspace, Class E airspace, Class F airspace or Class G airspace;"

As it often does the ANO is contradicting itself and talking bollox, if Class G was controlled airspace then how on earth (or above it) could you have an ATSOCAS?

In the UK there are currently five classes of airspace; A,C,D,E and G. The classification of the airspace within a FIR determines the flight rules which apply and the minimum air traffic services which are to be provided. Classes A, C, D and E are areas of controlled airspace and G is uncontrolled airspace.

[Jim59]

As it often does the ANO is contradicting itself and talking bollox, if Class G was controlled airspace then how on earth (or above it) could you have an ATSOCAS?

Hence ORS4 No. 1238 - General Exemption E 4536. During the drafting of the Air Navigation Order 2016 class F and class G airspace were erroneously included in the definition of controlled airspace in Schedule 1. This exemption is necessary to alleviate from any adverse consequences as a result of this, until such time as the Order can be appropriately amended.

[bookworm]

Since when is it a requirement to carry a radio at all?

What I meant to write was, "For non-commercial VFR in the UK, if communication is required, the equipment requirement is for only one COM radio."

[Piper.Classique]

So, have I got this right, I can leave the 25 spacing radio in and use it as long as my route doesn't require me to use 8.33, at least until september?

[Jan Olieslagers]

Depends on how you define "to use 8,33". The one case where you could theoretically get in trouble is when you use the "old" radio on a new "frequency" of which a neighbour frequency is in active use; you could then disturb communications there and that might perhaps be traceable to you and then you might be invited for tea with no biscuits.

Example: published frequency = 118,005, you tune in with your 25 kHz radio set to 118,000. Perfect communications however you are also transmitting into the 118,020 (or was it 118,015?)channel (we shouldn't speak of frequencies any more, to be correct, but rather of channels).

I do not think there are many cases yet of adjacent channels being in use, but have no references.

[LowNSlow]

When I picked up the mighty Airtourer from Elstree after she had her new Trig 8.33 and Mode S fitted I had an interesting chat with the gentleman in the tower. Apparently since they went 8.33 they are getting a lot of interference from French radio which they never had before........ wasn't 8.33 supposed to stop this? Doh, EU Against Sensible Aviation strikes again!!

[ShyTorque]

LowNSlow, Elstree haven't changed their frequency from 122.4, have they?

[MrAverage]

Elstree is definitely not 8.33 yet and I can't believe anyone in the tower would have said it is. The change over is due at the end of this summer.

For many decades we've had clear reception of French aircraft (transmitting in French) during certain weather conditions on 122.40. It's possible the controller who said that is fairly new to Elstree.

[BEagle]

Particularly during stable, anticyclonic conditions, 'Sporadic E' can cause refraction of VHF signals so that they are heard well outside the intended area of coverage. We used to get a lot of French aeronautical VHF at Brize on one of the normal approach frequencies.

On my drive to AeroExpo last year, French VHF-FM was coming in loud and clear over my car radio! Back in 1967, our school CCF used the '88 set' ex-army radio, which worked on 4 frequencies at around 40 MHz. Because Channel B (41.4 MHz) was close to the BBC TV 405-line Channel 1 signal on 41.5 MHz, a rivet had been installed in the channel selector, giving access only to Channels C&D. On the day of a CCF Field Day, sporadic E was so predominant that Channel C was completely blocked by foreign TV sound, leaving us with only one channel to use.

As the '88 set' pre-dated BBC-TV in many parts of the country, complaints about 'army interference' steadily mounted in the 1950s-60s as the '88 set' began to replace the ancient HF '38 set' at CCFs, leading to the blocking of Channels A&B - and it was very difficult to remove the rivet :\!

[LowNSlow]

ShyTorque, nope, it is still 122.4 which puzzled me when the chap mentioned the 8.33. Mr Average, I think he is quite new as I don't recall seeing him there before although I don't visit as regularly as I used to.

[Jim59]

AIP Supplement 009/2018 lists the stations that have converted and those due to convert within the next 60 days. Elstree is not listed.

[Roadrunner Once]

Short version:

You can use your 25kHz radio on any remaining 25kHz frequencies during 2018, but only until they change to 8.33kHz channels, which you can’t use it on. After 01/01/19 it is dead weight, as all frequencies should be 8.33kHz channels by then.

[Jim59]

You can use your 25kHz radio on any remaining 25kHz frequencies during 2018, but only until they change to 8.33kHz channels, which you can’t use it on. After 01/01/19 it is dead weight, as all frequencies should be 8.33kHz channels by then.

Except they won't!
The following assignments will remain on 25 kHz permanently:


121.500 Emergency Frequency.
123.100 SAR Auxiliary Frequency.
122.100 NATO Combined Frequency.
The VHF digital link frequencies 136,725 MHz, 136,775 MHz, 136,825 MHz, 136,875 MHz, 136,925 MHz and 136,975 MHz.
The ACARS frequencies 131,525 MHz, 131,725 MHz and 131,825 MHz.
Where offset carrier operation within a 25 kHz channel spacing is utilised (e.g. VOLMET).

[MarcK]

You can use your 25kHz radio on any remaining 25kHz frequencies during 2018, but only until they change to 8.33kHz channels, which you can’t use it on. After 01/01/19 it is dead weight, as all frequencies should be 8.33kHz channels by then.25kHz channels are also 8.33kHz channels. Are you saying that those channels won't be used????

[Jan Olieslagers]

They will be used - actually some are being used now - but under another name and with less bandwidth.

[BackPacker]

The following assignments will remain on 25 kHz permanently:


121.500 Emergency Frequency.


Actually 121.5 still uses 100 kHz frequency spacing. It was not affected in the earlier splits from 100 kHz to 50 kHz to 25 kHz, and it's again not affected now.

https://en.wikipedia.org/wiki/Airband

[VictorGolf]

What about SafetyCom on 135.475?

[MarcK]

They will be used - actually some are being used now - but under another name and with less bandwidth.How does that work, since the bandwidth of an AM signal is +/- the highest modulating frequency, which is about 3kHz? Or is it just more selective filters in the receiver?

[Jan Olieslagers]

is it just more selective filters in the receiver?Mainly narrower filters in the transmitter section. As I stated before: if one transmits on, say, 119,000 Mhz with a 25 KHz filter than one will also be received/heard on 119,0 - 8,33 and 119,0 + 8,33 - which is not what is intended.

But also narrower band filters on the receiving side, for the exact same reason, mutadis mutandis.

[Jodelman]

As I stated before: if one transmits on, say, 119,000 Mhz with a 25 KHz filter than one will also be received/heard on 119,0 - 8,33 and 119,0 + 8,33 - which is not what is intended.
Are you sure? The bandwidth of the transmitted signal is about 6kHz and a reasonably modern 25kHz radio would not interfere with the adjacent .833 channels.

[Jim59]

Actually 121.5 still uses 100 kHz frequency spacing. It was not affected in the earlier splits from 100 kHz to 50 kHz to 25 kHz, and it's again not affected now.

https://en.wikipedia.org/wiki/Airband

Good try! There are two slightly different things here. The permitted bandwidth of the transmission and the fact that 121.500 is protected by a guard band that can vary by region of the world. The The requirements are laid down in ICAO rules. The bandwith is 25 kHz but the frequency is protected by a guard band that is wider.

The European situation regarding bandwidth is in regulation 1079/2012 where it states 25 kHz channel spacing.

It says in "Amendments to Annex 10, Volume V, Chapter 4" of Oct 2011
4.1.1.1 The block allotment of the frequency band 117.975 – 137 MHz shall be as shown in Table 4-1.
b) 121.5
Emergency frequency
In order to provide a guard band for the protection of the aeronautical emergency frequency, the nearest assignable frequencies on either side of 121.5 MHz are 121.4 MHz and 121.6 MHz, except that by regional agreement it may be decided that the nearest assignable frequencies are 121.3 MHz and 121.7 MHz.

4.1.3.1.6 The emergency channel (121.5 MHz) shall be available only with the characteristics as contained in Annex 10, Volume III, Part II, Chapter 2 for equipment with 25 kHz channel spacing.

COMMISSION IMPLEMENTING REGULATION (EU) No 1079/2012 of 16 November 2012

Article 2
4. The conversion requirements shall not apply to frequency assignments:
(a) that will remain in 25 kHz channel spacing on the following frequencies:
(i) the emergency frequency (121,5 MHz);

[Roadrunner Once]

25kHz channels are also 8.33kHz channels. Are you saying that those channels won't be used????

No, they are 25kHz frequencies, not channels.

If someone wished to retain a 25kHz set purely on the offchance they needed to call 121.5, or their presence is required on NATO Common, that’s up to them I suppose. But they’ll need an 8.33 kHz set for anything else after 01/01/19.

[MarcK]

I see that this is all a bit of smoke and mirrors. ATC won't say "121.5", instead they will say "121.505" (i.e. the even 25kHz frequency names won't be used), even though the radio will actually transmit/receive on 121.500 MHz. So all of you who have been asked in the past to monitor 121.5 will now have to monitor "121.505".

Similarly, you can't select "118.25" on your radio. You select "118.255" which is really frequency 118.25 MHz. Then when you fly to the US you will have to add 0.005 to each frequency assignment. Except for VOR/ILS?

[Jan Olieslagers]

Bad example: 121,500 remains what it was, see #34.
But right about the 118,255.
VOR/ILS are not affected, AFAIK.

[MarcK]

But will the radio let you tune "121.500"? If you wanted 122.500 the radio wants to display 122.505. Does it know something special about 121.500? As I said, I don't have or need an 8.33 radio, so I haven't actually twiddled the knobs.

[The Fat Controller]

An 8.33 CAPABLE radio can select ANY current ATC frequency including 121.500 and will always be able to do so.

[Andrewgr2]

Unless it is an Icom A220. On this radio you have to go 2 levels into the menu to select a 25khz frequency when in 8.33 mode. A firmware upgrade to make it perform like everyone else’s radios is awaited. In the meantime it will be almost unusable in a mixed 8.33/25 environment.

[BackPacker]

But will the radio let you tune "121.500"? If you wanted 122.500 the radio wants to display 122.505. Does it know something special about 121.500? As I said, I don't have or need an 8.33 radio, so I haven't actually twiddled the knobs.

Yes, the radios are intelligent. If you select 122.500 on the radio, it knows it's a 25 kHz separated frequency. So it'll transmit on 122.500 but on receive will use a 25 kHz wide filter. On the other hand, if you select 122.505 it knows it's an 8.33 kHz separated channel. So it'll again transmit on 122.500 but on receive will use the 8.33 kHz wide filter.

All this is done to make the system fairly idiot-proof. You don't have to worry about 25 kHz or 8.33 kHz in reality. All you need to do is dial-in the frequency ("channel") that's been given to you, and the radio will take care of the rest. Also the 8.33 "channels" that are now being used cannot be tuned on a 25 kHz-only radio anyway, so that would hopefully give a clue to the pilot that he's doing something wrong.

(Unless it's an Icom A220, apparently.)

[MarcK]

Thanks. That makes sense. I hope this "improvement" never crosses the pond.