What does the controller mean?

Hmmmm…. that’s a bit of a weird one, don’t think I ever got that. I would also interpret it as fly directly to base for rwy 5, two miles out from the threshold. It is, however, rather ambiguous.

PS: in the US, rwy numbers 1 through 9 are single digits, no leading zero

I think more often, in the US, the controller answering in response to an initial call would say ‘make two mile right base’ versus asking you to report right base, and leaving how to get to that position ambiguous.

At my home airport they’ll do that if trying to make space for me to land between other traffic. This would generally mean for the initial call I’d fly diagonally away from the airport to enter a base leg that far out. Then when they see a gap, they will instruct to fly directly to short final, from wherever I am on base at that point. If by chance I haven’t by that stage reached a two mile base, for example I’m 1.5 miles from the airport, they’ll tell me ‘start your base now’.

Silvaire wrote:

When I am instructed in the US to report base, it means go directly there ASAP… there is no underlying ‘standard join’ protocol in use at ATC airports. The ‘game’ is to occupy valuable space in the sky for as little time as possible, and he wants to get you on the ground and out of the way. In my experience hanging about and/or flying around the airport will not be popular with ATC if you are told to report base on an initial inbound call, and he will likely think you didn’t understand the instruction.Again in my experience, the word ‘cleared’ is used only for landing on a US VFR arrival.

To my understanding all this is exactly as in Europe, as long as ATC rules.

I agree with Silvaire and Hub. I frequently get Report Left Base, keep it tight" followed by " Cleared land, keep it tight" before I make my base call, as ATC see I’m making a near-VME approach in my tailwheel. I’ve asked “Will it be vacate at end?”, and, on receiving an “Affirm” have turned final low over the 1700 metre runway.

I think the clearance is to position on extended base but to report at 2nm from the field, i.e. inside the ATZ therefore under his control, but still outside a normal circuit pattern in case the clearance needs to be modified for other traffic.