" if any difficulty is encountered the pilot should not hold while awaiting Clearance unless so directed by ATC. In such circumstances, pending receipt of the Oceanic Clearance, the aircraft should continue to maintain the flight level cleared by the current control authority."
Well that pretty much sums up what happens in reality on the South Atlantic..you may never get a "formal" Oceanic clearance, Gander or Shanwick style..you just have keep going, try all the frequencies and stand by to give lots of forward estimates when you do finally get through.
"..Have great problems with Mumbai HF."......join the club
