Transition Altitude for Oceanic Airspace?
 

Does anyone know the transition altitude for Oceanic Airspace?

The base of most controlled oceanic airspace in the North Atlantic is obviously Flight Level 055, implying a transition altitude well below the North American 18,000'! However I have never seen it written in any of the flight planning publications.

Do you wqant to get that low over an ocean???? <img src="eek.gif" border="0"> <img src="eek.gif" border="0"> :)

5500ft in UK section - dunno about the rest !

Pointer:
It's in connection with (military) maritime patrol flights where one often operates below FL055 without need of a clearance.

Eric T:
Is the UK 5500' written down anywhere? The problem, I guess, with 5500' would be the need to cross check with 1013/29.92 before reaching 5500' to see if one had reached FL055! (and thus remain below controlled airspace, if that was the aim!)

VPI - I've not seen it written in UK AIP , but I got info from a senior ATCO @ Shanwick. FL55 is never allocated to prevent conflict with aircraft at the base using QNH (Nimrods perhaps ?)

Thanks a lot - Senior chap at Shanwick good enough for me!