By James Cannonand Franklin Richey jim_cannon@bellsouth.netfrank.richey@erau.edu

Transitioning from an IFR flight plan to an oceanic route is a relatively simple procedure when crews plan for this transition. The oceanic clearance should be received, verified and accepted long before the aircraft approaches the oceanic boundary. En route charts contain the appropriate frequency to request the oceanic clearance, but experienced international crews already have the frequency noted on their flight plan along with the appropriate position when the controlling agency may first be contacted. Prior preparation is critical when operating in international airspace.

A professional flight crew should be able to copy and read back an oceanic clearance without a misstep. Oceanic clearances contain an entry point, en route waypoints consisting of latitude and longitude positions, the exit point, a clearance altitude and a Mach speed to be flown while within the airspace. Even if the aircraft is cleared to fly a specified track, the controlling agency requires a read-back to include each waypoint on that track.

When requesting an oceanic clearance, the crew must compute an estimated time of arrival (ETA) at the oceanic entry point by factoring in the estimated time en route (ETE) from the master flight plan and convey that ETA to the clearing authority.

Clearance is usually received from air traffic control (ATC) approximately 200 mi. before reaching the gateway fix when flying eastbound from North America. If a clearance has not been received when the flight is within 20 min. of the fix, the crew must call the appropriate agency (Gander, New York, Shanwick or Santa Maria Oceanic Control) on either VHF or HF and request the oceanic clearance.

During westbound flights from Europe:

North of 50 deg. N. Lat. — Contact Shanwick before 02 deg. W. Long.

South of 50 deg. N. Lat. — Contact Shanwick before 01 deg. W. Long.