Multiple Frequencies

[pilotwolf]

Whilst transiting a zone at the weekend I overhead the following conversation on the radar frequency I was using - there were 2 published:

G-XXXX: XXXX Approach request zone transit.
APPROACH: G-XX Call on 123.45,
G- XXXX: XXXX Approach G-XX, 123.45
APPROACH: G-XX transit approved, etc.

We didn't change freq but heard G-XX on both calls and the same controller answered him on both calls, but presumably G-XX changed to the other frequency as requested.

So...

When its quiet is there any point operating 2 approach frequencies - especially if the same controller is working both?

Why if we could hear both transmissions did G-XX need to change freq? Was it a case of same guy using 2 transceivers? Is so why could we hear him both times?

Similarly - why have an approach frequency and a tower frequency at small field when again the same controller is operating both.

Seems to me to be an unnecessary increase in pilot workload - especially in view of the numerous potential infringements in the area.

[flower]

The system you are questioning is one we use at Cardiff. Due staffing we are only able at the moment to have 2 radar controllers available between the hours of 9-5. However we always want the aircraft to communicate on the correct frequency , so no hastle for either the pilots or ATCOs over which frequency to select Dependant on the time of day.
Outside of these hours we "bandbox" 3 frequencies together during the period 9-5 however two controllers would be handling 3 frequencies.
Safety wise it has many advantages, sometimes again due staffing we are unable to split the positions permanently during the day but again the aircraft are on the correct frequency so if there is a necessity or ability to split back to two positions it only takes the pressing of one button and the ATCO has the positions split, which means you are not instructed to change frequency.
It may seem daft but it is a good ,safe and quick system for us to use.

[5milesbaby]

You think just 2 can be bad, at night the LACC South sectors are put together and can have up to 7 coupled together. Really gives you a head-in-bucket sound :} :} :} :}

[ex-EGLL]

You think 7 is bad, try Montreal on a midnight, they have 16 and want more, and thats in BOTH official languages!!:(

ex-egll

[Lon More]

Done in Maastricht at nights as well. Also due to size of collapsed sector (e.g. From GES in North to REFSO in South) R/T coverage not guaranteed from one transmitter so 2 freqs in use .
Also when neccessary UHF can be coupled to the VHF.

[contact_tower]

Also when neccessary UHF can be coupled to the VHF.

Quite essential when working twr or app during periods with 50/50 CIV/MIL traffic. Thankfully the MIL guys use VHF more and more.

[Iron City]

Is that why you guys have to go to 8.33MHz?

[M609]

Well, the use of VHF by the military are on allready established freq. Since we have a integrated ATC system, we have had dual UHF/VHF capability for all sectors and twr/app units since the beginning of time! (Since the early 50s anyway :E)
They just elect to use VHF with ATC, and use UHF for the tactial stuff. (CRC, FAC inter formation etc). USAF/RAF on deployment tend to use UHF more often though.
The number of VHF freq established has not increased due to this anyway.

[7p3i7lot]

While we are on the subject of ATC using multiple freqs by the same controller let me ask this.
In the US (or in the old country for that matter) is there an ATC rule/procedure that says you can't just move the users to one freq?
eg. On weekends when the tower presumably has less manning, they routinely have one controller working ground and tower (sometimes clearance as well) yet working 2/3 different freqs.

This leads to confusion and stepped on transmissions as the users are unaware (initially) that one ATC person is working multiple stations (and functions). Sometimes ATIS will state that "tower and ground are combined on xxx.xx" but often times there is no such warning.

Anyone have a clue why they don't just put everyone on the same freq so we don't step on each other or worse miss a critical clearance?

:uhoh:

[Scott Voigt]

First off, ground and local should not be combined. That is something that the FAA has been complained about many, many times. You will find this happening on the midnight shifts when they go down in staffing for the night. However, this should be the only time.

There are SOPS ( Standard Operating Procedures ) that do state to keep people on the appropriate frequencies. It makes it easier to split off the positions, but it also keeps the frequency spectrum as it is supposed to be used. Shouldn't be using a ground frequency in the air due to the range of use limitiations. You are going to possibly be bleeding over to someone elses's ground freq, if you extend the range while airborne.

There is a way that you can keep from getting stepped on and that is mechanical. Radios can be set up to rebroadcast from other frequencies. The Center equipment was set up to do so, however, it would have cost more money to pair all the frequencies to allow this to happen. So we don't. The radios that the towers have could be made to do this if the capability were added to it, again at an additional cost.

As to enroute frequencies and using the same ones. In areas that we can do this, we do for the very reason that you cite. However, due to the large volumes of airspace some of our sectors have, when we combine up at night or even in the day in some areas, we can not get appropriate coverage at the low altitudes as well as some of the high altitudes.

regards

Scott

[5milesbaby]

In NATS (UK) we are able to 'cross couple' the frequencies together so that it seems you are all on the same frequency, as any transmission by anyone on a freq is then transmitted on all the others selected. At Swanwick we are able to select up to 12 frequencies at any one position, and have the capability to cross-couple 10 of these together.

[M609]

Over here everyone with com equipment newer then 1990 (thats all except some small twr units) can bandbox all frequencies in their panel. (Garex 210 or newer) However since even twr units usually have multiple TX/RX sets for each freq. (not counting back-up) having more then one TX bandboxed for each freq gives really bad reception for the customers.

[pilotwolf]

But my whole point was by requesting this pilot change frequencies the controller was increasing the pilots work load... I might have missed but not one seems to have explained why it couldn't have been left where he was as everyone could still hear them both... indeed some replies actually make the freq change seem even more unnecessary!

Simple unexpected freq change for 2 pilot airplane operation with autopilot may not be much trouble but what about single pilot R22 driver with no GPS, no autopilot, etc doing their best to avoid infringing one of the (?) 4 nearby zones? Unnecessaru increase in workload??

[flower]

Sorry pilotwolf I thought we had explained. we need you on the correct frequency in the event of us being able to split the frequencies again.
Also the frequency range of some means that they shouldn't be used outside a particular range.
If you were on the incorrect frequency to in the first place it would give you a mental nudge to check the correct frequencies for your next flight in that area to , thus reducing both controllers and pilots workload

[pilotwolf]

Right! Got it now - thanks :ok: