For over 50 years, every commercial flight crossing the North Atlantic eastbound through Canadian airspace would contact Gander Oceanic Control at least 30 minutes before reaching the coast to negotiate a three-part clearance covering route, speed, and altitude. Without that explicit radio or datalink handshake, pilots faced an immediate halt in domestic airspace or an entry into a holding pattern over Newfoundland. That mandatory pre-entry clearance has now disappeared in favor of a new approach to crossing this airspace.