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.
South of 45 deg. N. Lat. — Contact Santa Maria OAC at least 20 min. before crossing the OAC boundary. Contact Santa Maria radio on HF. Pertinent information on clearances can be found on the Atlantic (H/L) 1 en route chart.
In 2006, nearly 400,000 flights crossed the North Atlantic, making that airspace some of the busiest in the world. Since normal land-based communications and radar surveillance are not available over the North Atlantic, horizontal and vertical separation of aircraft is ensured through a strict set of parameters and procedural disciplines.
Clearances for Pacific crossings are usually received on the ground prior to takeoff. If the clearance is delayed until after the aircraft is airborne, as is the case in the Atlantic, the clearance must be received before the aircraft crosses the oceanic entry point.
A good pre-departure technique when conducting oceanic operations is to test the HF radios long before takeoff. At minimum, before entering oceanic airspace, the crew must perform a functional test of HF radios, and ensure that all navigation equipment used for the trip is in working order.
Mach number technique must be used for all oceanic operations. The controlling agency can only plot the approximate position of aircraft, based on position reports. Pilots must maintain their Mach number within a tolerance of +0.01, unless a change is granted by ATC. After leaving oceanic airspace, the pilot is expected to continue to fly the flight plan Mach number until ATC authorizes a change in airspeed. Pilots must notify oceanic control if their ETA at the next reporting point changes by +3 min. when operating on a designated track, or by +5 min. when operating off the designated track system.
Organized Track Structure
To handle the heavy air traffic between the U.S. and Europe, an organized track structure (OTS) is built every 12 hr. (due to constant weather changes). The entire Atlantic Control Area is divided as follows among control centers:
Reykjavik (to the North Pole)
Shanwick and Gander Oceanic
Santa Maria Oceanic — north of 27 deg. N. Lat.
New York Oceanic — North of 27 deg. N. Lat. but excluding the area west of 60 deg. W. Long. and south of 38 deg., 30 min. N. Lat.
The North Atlantic Track (NAT) Structure is a region of controlled airspace where IFR rules apply. Pilots flying the NATs are expected to use the Mach number technique to smooth the flow of traffic and enable en route step-climbing.
There are fixed airways (composite routes) in the Pacific, which are operational 24 hr. a day. These composite routes are located in U.S.-controlled oceanic/arctic airspaces called control areas (CTAs) or flight information regions (FIRs). Pursuant to the Chicago Convention, the U.S. accepted responsibility for providing ATC services over the domestic U.S. and within certain areas of the western half of the North Atlantic, the Gulf of Mexico, the Caribbean and the North Pacific. Within these CTAs/ FIRs the U.S. applies oceanic separation procedures consistent with ICAO regional procedures.
Standard ICAO oceanic procedures apply to Pacific routes, with minor differences (in spacing and separation) from those on Atlantic routes. In the Pacific, Oakland Oceanic CTA extends out to 165 deg. E. Long. (to the Tokyo CTA) and to 130 deg. E. Long. (Manila FIR). As a result, thecontrols most of the Pacific airspace.
There are five routes that make up the North Pacific (NOPAC) routes between Alaska and Japan. The two northern routes are for westbound traffic, and the three southern routes are for eastbound flights. An organized route system, made up of six composite routes (ATS routes), is used for aircraft operating between Hawaii and the Los Angeles/San Francisco area. The routes are between FL 290 and FL 410 and use the same rules as the NOPAC routes.
Beyond approximately 200 nm from a land-based VHF communication station, HF radio is used as the main communication source for oceanic operations. A recent advance in communications technology allows reporting via satellite and communication over water via the aircraft's flight management system (FMS). This is accomplished using automatic dependent surveillance-contract (ADS-C) and controller-pilot data link communications (CPDLC). While this is the future of oceanic flight communications, currently only a few business aviation departments have this capability.
Most operators continue to use HF as their primary means of oceanic communication. The HF frequencies used en route are determined not only by the particular route flown, but also by atmospheric conditions and the time of day. Generally, lower frequencies are used during the night and higher ones during the day.
Each oceanic center has groups of HF frequencies assigned. These frequencies can be found in numerous resource locations, but most crews use the en route chart for the particular part of the world to pick up area frequencies. When receiving the oceanic clearance, the crew may request the “primary” and “secondary” HF frequencies. It is mandatory, while en route, that the primary HF be monitored.
There is a great deal of background/static noise on most HF radios. In the early days of oceanic flight, radio operators were used to maintaining HF listening watches. With two-pilot cockpits, that duty later fell to the pilot not flying the leg.
On first contact with the controller, the crew should perform a SELCAL (Selective Calling Radio System) check so the HF frequency does not have to be continually monitored by the crew. If the controlling authority needs to communicate with the crew, they will send a transmission through a ground-based encoder that is specific to that aircraft. An onboard alert tone and light will be initiated in the cockpit by the encoded signal thereby notifying the crew to reply.
As is the case when operating in any non-radar environment, the aircraft crew is required to make position reports at all designated reporting points or at certain designated lines of latitude and longitude. When crossing the boundaries between Oceanic Control Areas, a position report is made to the airspace controlling authority responsible for the airspace being entered.
Over the Atlantic, on east and west tracks, position reports are required at each 10-deg. line of longitude if the aircraft can cover that distance in 1 hr. or less. Similarly, if the aircraft cannot reach the next 10-deg. line of longitude in 1 hr., an intermediate position report is required at each 5-deg. line of longitude. Similar timing rules apply for aircraft flying on north and south tracks. Position reports are required at each 5 deg. of latitude, with intermediate reports required for slower aircraft.
In the Pacific, position reports are required at mandatory reporting points indicated along fixed routes on the en route charts. If the aircraft cannot fly between mandatory reporting points in 80 min. or less, midpoint reports are required at intermediate points, also printed on the charts. Position reports for flights along non-published routes will be made at significant points listed in the flight plan, or as instructed by ATC.
Position Report Format
A position report to ATC should include the following in the order specified:
Position — over a mandatory reporting point
Time () over the position
Next fix and time (UTC)
Name of the following fix
Optional temperature and wind readings
An example of a position report and the controlling agency's response: (Aircraft) “Gander, N123JC, Position.” (Gander Center) “N123JC go ahead.” (Aircraft) “N123JC position 51 North 40 West at 0310; Flight Level 410; estimate 52 North 30 West at 0358; 52 North 20 West next. Temperature minus 54, wind 260 diagonal 60, over.” (Center) “Roger N123JC, position 51 North 40 West at 0310, 410, 52 North 30 West at 0358.”
In this example, 51 North 40 West represents the position of north 51.00.0 and west 040.00.0. Proper position reporting requires brevity, due to the high volume of communications on HF. This format should be used for all HF position reports, substituting waypoint names for latitude and longitude when so indicated on the en route charts.
A position report is required at all Atlantic, Pacific and European FIR boundaries. When departing from U.S. or Canadian cities, reports should be made at all compulsory reporting points on the FIR boundary.
On the North Atlantic plotting chart, there are blue triangles printed on the FIR boundaries that represent the transition from local to oceanic control. For those flights departing gateways in Newfoundland (Gander, St. John's and Stephenville), there are no triangles along the FIR from St. Anthony south to Gander. East of Gander the first mandatory reporting boundary is at 50 deg. W. Long.
No named reporting points are designated on the European FIR boundary, so position reports must be made using latitude and longitude coordinates. The same is true of Guam and Tokyo CTA/FIR. The flight crew should expect ATC to require confirmation approaching and reaching all FIR boundaries.
In the unlikely event that HF radio communications are lost, the flight is expected to continue on the last assigned oceanic clearance. Every effort should be made to relay position reports on the VHF guarded frequency, 121.5, or when over the Atlantic, via the air-to-air frequency, 131.8. Traditionally, oceanic aircraft have always monitored 123.45, in order to render communication assistance to other aircraft within VHF range. Over the Pacific the same procedures exist with the addition of VHF frequency 128.95.
Industry best practices mandate that flight crews not only file flight plans for each proposed flight leg but maintain a copy of the flight plan in the cockpit as reference during the flight.
Technology has advanced the art of navigation from a desktop exercise using a chart, a ruler, map, protractor, Jeppesen CR-3 and a No. 2 pencil. Now crews are equipped with laptops, iPads, smart phones and GPS-driven FMSes with moving map displays. Both weather and winds at altitude are available in a current format. These advances have caused many crews to become complacent in the navigation phase of flight operations, especially during domestic flying. When it comes to international flight ops, any complacency, especially pertaining to navigation, cannot be justified.
Oceanic flight planning and navigation require skill and diligence. Reviewing approach charts, standard arrivals, departures and en route charts, well ahead of arrival, provides the crew with a familiarity of nav procedures and waypoints that will come in handy when it's time to use them. Not being familiar with the name of or where to find an important intersection on a local chart, following a 6- or 8-hr. ocean crossing, is unprofessional and inexcusable.
To avoid making data entry errors, loading an international flight plan into the aircraft's FMS should incorporate a two-person process of insertion and verification. Computerized flight planning and modern communication techniques allow for the plan on file to be received and downloaded electronically. Despite this convenience, it is critically important that this process be overseen by one pilot and verified by the other.
During the previous decades of organized oceanic operations, hundreds of navigation errors have been recorded. The vast majority of those errors have been flight crew-induced during initialization or in the course of updating while en route. A time-proven manner of avoidance of such crew-induced nav errors is to double-check all FMS initial and updated position entries by both pilots.
When an oceanic clearance is received, the flight crew should plot the waypoints on an oceanic plotting chart to ensure the coordinates received in the clearance match the coordinates that were programmed into the FMS. If there are any revisions to the flight plan, they will be entered in the correct position on the master flight plan and the old waypoints crossed out. An initial plot may take place, prior to departure, that represents the requested oceanic clearance. Once the clearance is received, as is often the case when traveling eastbound from the U.S., a second plot should be made.
Proper En Route Protocols
As soon as practical after departure, one crewmember, typically the pilot monitoring (PM), should record the actual departure time on the master flight plan. This allows an accurate estimate to a gateway that may be fast approaching (examples: westbound out of London or Glasgow) and to have an accurate ETA to the destination. The estimate provided by the FMS may not initially be as accurate as the crew would like. It also will not necessarily provide an accurate ETA to an FIR boundary or initial track entry point during climb-out should the controlling agency request an estimated time of arrival at a particular fix along the flight routing.
In addition to the time to each fix along the flight plan, the crew should have an estimate of how much fuel will remain at each fix. Before takeoff the PM should record the total fuel load on the master flight plan and in parallel with listing each waypoint's ETA, the PM should note the estimate of the total fuel remaining at each fix.
Passing the oceanic gateway outbound, the crew should perform a gross-error check to ensure the long-range nav equipment is performing properly. This is accomplished by flying directly over the gateway, if practicable, and verifying that the aircraft is on the proper outbound course. Short-range navigation facilities may be monitored and compared to detect any deviations. This will help to detect any errors in the position updates since departure.
When approaching each waypoint, the crew should review the master flight plan and record all pertinent information, such as the fuel remaining and elapsed time. Also it is important to check that the present and following waypoint are in accordance with the clearance that was received by ATC. Overhead each waypoint, the crew should ensure that the aircraft turns in the proper direction and that the heading and mileage conform to the master flight plan estimates.
Once passing an en route waypoint in any non-radar environment it is important that the crew make a position report as soon as possible. Each cardinal clock position, on the hour, quarter past, half past and three-quarters past the hour, diligent navigational discipline dictates that the crew plots the actual position of the aircraft using the FMS/GPS coordinates to determine if they are on course and within the tolerances of the oceanic procedures. Each mark should fall directly on the plotting charts route directory that was drawn by the crew, prior to entering the oceanic airspace.
At the inbound gateway, the crew should cross-check VOR/DME positioning if available but continue to navigate using the FMS/GPS. In the event of a contingency, the crew will immediately notify ATC to inform them of the situation and, if required, request a revised clearance. A clearance should be received before any action is taken to change altitude or the route of flight. If ATC cannot be notified, the crew should broadcast their request on 121.5 until a clearance is received.
Long-Range Nav Failure
If one long-range navigation system fails before takeoff, the crew should consider the following options:
Delaying the departure until the system is repaired, or
Filing a revised flight plan using special routes, which have been issued for aircraft with partial loss of navigation capability.
Note: These special routes are available only if the remaining navigation equipment meets the minimum navigation performance specifications (MNPS) and the requirements in ICAO Annex 6, Part 1 are met using short-range navaids. Request a clearance above or below MNPS airspace.
If one long-range nav system fails after takeoff, but before the aircraft reaches the oceanic boundary, the crew should consider the following options:
Landing at an en route airport that has suitable repair capabilities, or returning to the departure airport.
Filing a revised flight plan using the special routes as just described.
Requesting a clearance above or below MNPS airspace.
If one long-range nav system fails after the aircraft crosses the Oceanic Control Area boundary, the crew may continue to operate the aircraft in accordance with the oceanic clearance received, recognizing that the reliability of the total navigation system is significantly reduced.
If, after entering oceanic airspace and losing one navigation system, the remaining system fails or gives an indication of degraded performance, the flight crew must immediately advise ATC of the loss of navigation equipment.
After assessing the circumstances, consult with ATC to select one of the following optional courses of action:
Continuing to destination.
Diverting to a suitable alternate.
In addition to the forgoing,
Obtain an appropriate clearance from ATC prior to any deviation from the current oceanic clearance.
Keep a special lookout for possible conflicting traffic, and use all available outside lights.
Using VHF radio, attempt to establish voice contact with adjacent aircraft to assist in maintaining separation.
Monitor the aircraft position on the plotting chart every 5 min. If no instructions are received from ATC within a reasonable period (approximately 10 min.) after notifying them of the loss of navigation systems, the pilot should clear the oceanic track and use dead-reckoning procedures to continue the flight.
Immediately climb or descend 500 ft., if at or below FL 290; or 1,000 ft., if above FL 290.
Initiate a turn 90 deg. right/left of course, preferably in a direction away from any organized track in the area.
Continue on the 90-deg. offset heading until 30 nm from the original assigned track. Use timing procedures to estimate the distance flown. (If ground speed is 360 kt., or 6 nm per minute, fly the offset heading for 5 min.)
When offset by 30 nm, turn back to the original heading to parallel the original track and continue the flight.
Plot new waypoints (now offset by 30 nm from the originals), using the heading and ETE between points on the master flight plan to define them. Note: The ETA to the next waypoint will be later than planned because of the time spent flying to the offset course (5 min. in the example above). Adjust all subsequent ETAs by that amount.
Over each waypoint, turn to maintain a new course, if required, using the magnetic compass. Make note of the course, time of waypoint passage, time to the next point, fuel remaining and fuel burn between points on the master flight plan.
Continue to monitor both the assigned HF frequency and the appropriate VHF frequency (121.5, 131.80 Atlantic; or 128.95 Pacific) for any position reports in the vicinity. Use the information on winds and temperature aloft to update flight plan estimates.
Monitor all Volmet (i.e., meteorological) reports, significant weather (SIGMETs) and forecasts for selected airports that are broadcast at specified times on HF frequencies. The HF frequencies and times of broadcast can be found on the Atlantic Orientation Chart or in the meteorology section of the Atlantic Jeppesen binder. Monitoring these reports en route helps crews select a suitable alternate landing site if the weather is below VFR at the intended destination.
If radio contact can be re-established, advise ATC of the situation and actions taken. Request an amended clearance, if necessary.
Again, with proper preparation, flying the oceans can be a highlight in a professional aviator's career and deliver cultural insights, new experiences and vistas that make a life of travel so rewarding. BCA
Excerpted from Practical Applications in Business Aviation Management, by James Cannon and Franklin Richey, published by Government Institutes, 2012; www.govinstpress.com