Numbers in brackets after frequencies?

[K2GMZ]

Hi there, Might sound like a silly question but what do the bracketed numbers after listed frequencies mean?
I'm assuming the altitude ranges in which these freq's are to be used for? Tampa Approach as an example.

TAMPA APPROACH: 118.15 ;(001-150) 118.8 ;(220-360) 119.65 ;(151-219)

I'm a real newb at the aviation stuff so excuse the question!

Thanks.

 

[WX4BLF]

It’s the headings of that sector. Meaning if you’re flying 001-090 you’d use one frequency. Another if you’re on another heading. ATC is divided into sectors and you might change frequencies 2 or 3 times during approach or departure before ever contacting tower.


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[K2GMZ]

Got it, thanks!

 

[DaveNF2G]

More accurately, it is the range of bearings from the airport's VOR covered by that frequency. One arc covers aircraft operating on a bearing of 001 degrees to 150 degrees from the VOR (roughly due north to southeast), etc.

 

[majoco]

It’s the headings of that sector.

Not the aircraft heading, that's immaterial. As Dave says, it's a sector of bearings from the VOR that is assigned a particular frequency.

 

[abqscan]

In this case, the reference point is the airport, not a VOR. For it to be a VOR, it would have to specifically reference a VOR, or other navigational point, i.e., an VOR airway.

 

[KB4MSZ]

I am glad I saw this thread

 

[majoco]

I'd have to see the approach chart to see that the sectors were based on the airport and not the VOR.

 

[DaveNF2G]

It really only makes a difference if the nearest VOR is not actually at the airport, which does occur sometimes.