Radio procedures TMA vs CTR?
 

If I’m flying within a TMA and talking to approach or whoever controls the TMA, when about to fly over the top of a CTR, is it considered good practice or useful (or polite) to switch to the tower frequency and introduce myself before switching back to the TMA? Or is that adding unnecessary complication and I can assume that the TMA will advise tower of my presence if necessary?

Take your lead from the controller you’re already working with. If in doubt you can always ask at the time. But if you will penetrate airspace belonging to another airfield you cannot assume clearance and it remains your responsibility.

Don't know about other countries but in the UK, if you're in a TMA you will be IFR and hence your cleared route will allow you to cross over a CTR remaining with the one controller.

I will be VFR. Here the TMA around 3 major airports and a whole bunch of small airstrips is class D and extends 1,500' to FL145. Within that, the CTR around each airport extend sfc to 3,500' or 5,000' and is also class D.

Don't know the procedures where you are, but I would not be changing frequency without a prompt from the controller who is working you.
If in doubt, ask him/her, as you're approaching the CTR boundary.
Don't just call the tower without checking it's ok. Co-ordination between ATC units in respect of "shared" airspace or traffic goes on behind the scenes, either verbally or electronically, and you'd be surprised at how time consuming it is.
Calling one ATC unit while being controlled by another could throw a spanner in the works.

Have the TWR freq on box 2 to give you a heads up about what’s happening but as has been stated, stay with whoever you’re talking to inside controlled airspace until told to speak to someone else.

Thanks all. That makes sense

It would help if you told us where 'here' is; '5Y' means nothing to most of us.

It’s north of 5H and east of 5X.

hth

so west of 6O and south of ET then :)

Still means nothing to me...........

:D

Sorry MrA, I'm not being deliberately obtuse. Just low profile!

I doubt that including which airspace prompted your question would identify you!

You stay on the frequency for the airspace you're in. Simple as that.

The tower controller will coordinate with the approach controller before sending aircraft into the TMA, and if relevant the approach controller will give traffic advisory/ensure separation depending on airspace classification.

I'd be pissed if you just left my frequency when you're in my airspace :)

Edit: Whatever you do on your standby radio, is up to you..... but I dare you not answering me if I call you. Oh, and I'm sitting next to the tower controller, so if you mistakenly answer me on his frequency..... I will know!