6-1 CHAPTER 6. FLIGHT EXECUTION GUIDANCE FOR OPERATIONS IN OCEANIC
AND REMOTE CONTINENTAL AIRSPACE
6.1 General Information. The main focus of this guidance is operations in oceanic airspace.
The guidance is also applicable to some operations in remote continental airspace, where LRCSs are used.
6.1.1 Checklists. In Appendix D, Sample Oceanic Checklist, we have included a sample oceanic checklist tailored from the ICAO version, in both condensed and expanded forms. The checklist is designed to encourage an orderly task flow and reduce oceanic vertical, lateral, longitudinal, and timing navigation errors. Similar to the ICAO version, the checklist in this AC represents lessons learned from many years of flight in oceanic airspace, along with internationally accepted best practices for such operations.
Note: Y ou may tailor the abbreviated and expanded checklists to your specific needs and operational circumstances. Until you are experienced and familiar with all items on your tailored checklist, we recommend you refer to your expanded checklist to ensure you follow the procedures in their entirety.
6.1.2 P ilot Deviations—Common Causes. Technological advances in communications, navigation, and surveillance equipment have enabled aircraft to operate with ever-improving precision and accuracy. However, despite these improvements in capability, pilots continue to deviate from their current route clearances.
Note: Th e NAT ICAO Region publishes the Oceanic Error Safety Bulletin (OESB), which is an excellent resource for understanding how to prevent common errors. The current OESB can be found in the “EUR and NAT Documents” area of the ICAO website, in the “NAT OPS Bulletins” folder:
https://www.icao.int/EURNAT/Pages/EUR-and-NAT-Document.aspx.
6.1.2.1 Large Height Deviation (LHD). An LHD occurs when an aircraft is 300 feet or more off its assigned altitude. LHDs increase the risk of mid-air collision.
6.1.2.1.1 The most common causes of LHDs are:
1. ATC loop errors:
• Misunderstood or miscommunicated clearances.
• Inadequate ATC coordination.
2. Pilot deviations from assigned altitude:
• Following the flight plan rather than a clearance or revised clearance.
• Erroneous altitude programming in the FMS, such as a mistake in the step-climb entry.
• Misinterpretation/misapplication of conditional clearances.
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• Improper execution of contingency procedures.
• Turbulence encounters.
6.1.2.1.2 Data indicates that a majority of crew-related errors involve misinterpretation or misapplication of “conditional clearances.” Conditional clearances improve the efficient utilization of airspace, allowing ATC to assign altitudes that enable lower fuel burn. Event reports from ATC and flightcrews indicate that pilots misapply terms in the clearance such as “BY” or “AT”—terms, which have completely different meanings. See Table 6-1 below for examples of incorrectly applied conditional clearances.
Table 6-1. Examples of Incorrectly Applied Conditional Clearances
CLEARANCE CREW ACTION CORRECT ACTION Via CPDLC at 1714, crew conditionally cleared, “maintain F340, at 1725 climb to and maintain F360, climb to reach F360 by 1735, report level, due to traffic.”
Crew initiated climb early, reported (ADS-C) passing F354 at 1721.
Crew should have delayed commencing climb until 1725, and planned to reach F360 by 1735.
Via CPDLC, crew at F380, cleared F390 to cross 66N040W level.
Crew commenced climb to F390 at 40W (Mode C).
Crew should have initiated climb prior to 40W in order to cross 40W at F390.
Via CPDLC at 1945, crew cleared maintain F330, at 1952 climb to and maintain F350, climb to reach F350 by 1957, report level F350.
Reported (ADS-C) level at F350 at 1948.
Crew should have delayed commencing climb until 1952, and planned to reach F350 by 1957.
Crew cleared 68/40 64/50 IRBIM F360 M083 via HF voice, crew recleared to descend after passing 65N to be level F340 before 64N.
Crew commenced descent at 6529N/4650W.
Crew should have initiated descent after passing 65N and levelled at F340 prior to 64N.
Crew cleared 66/30 65/40 63/50 IRBIM LOMTA F400 M081. Via CPDLC, crew cleared climb F410 to cross 65/40 level.
Crew failed to climb as cleared and crossed 65/40 at F400 (ADS-C).
Crew should have initiated climb prior to 65N in order to cross 65N at F410.
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6.1.2.1.3 Your training program should provide your flightcrew with procedures that ensure all ATC clearances are complied with correctly, particularly clearances with en route restrictions such as changing FLs based on a coordinated time or a specific geographic position.
Note: Per ICAO NAT Doc 007, North Atlantic Operations and Airspace Manual, when flying in NAT HLA, if your aircraft is not using CPDLC/ADS-C, you must immediately report to ATC both when leaving and reaching a new FL. Doing so can enable the controller to identify and intervene when you have misunderstood or misapplied your conditional clearance.
6.1.2.2 G ross Navigation Error (GNE). The FAA defines GNEs as lateral deviations from course of 10 NM or greater. (Previously, the threshold was 25 NM).
6.1.2.2.1 The majority of today’s GNEs arise from pilots flying a very precise track to the wrong position because they failed to properly update their navigation system to reflect their currently effective route clearance. This can also result from a clearance or revised clearance that was incorrectly entered, misread, or misunderstood. Procedures to follow in the event of a revised clearance are included in paragraph 6.4.1.7. Examples of scenarios that have led to GNEs are:
1. P oor management of the M aster Document, resulting in crews not knowing the currently effective route clearance.
2. Incorrect waypoint entry procedures, particularly if the waypoints are not named and flightcrews must enter the full latitude and longitude.
Note 1: We use the term “currently effective route clearance” to describe what ICAO Annex 2 refers to as the “current flight plan,” or the most recently issued ATC clearance.
Note 2: W aypoints entered via full latitu de and longitude can produce misleading display names, with truncated or rounded minutes of latitude/longitude or longitude. For example, the following two points could have identical display names:
Waypoint Coordinates Avionics Display ID 5530N020W (N55°30’/W020°) N55W020 55N020W (N55° /W020°) N55W020
6-4 Note 3: Pilots should therefore always confirm the expanded coordinates of undesignated significant points (i.e., unnamed waypoints defined by geographic coordinates).
6.1.2.2.2 GNEs also result when the aircraft navigation mode is actually different from that assumed by the crew. This scenario typically occurs when the crew fails to return the flight guidance system to an RNAV mode (e.g., “LNAV”) after using heading mode (e.g., “HDG”) to maneuver the aircraft.
6.1.2.2.3 Although there are a number of causes of GNEs, pilot inattention has been the root cause of many navigational errors. ICAO NAT Doc 007, Chapter 14, Guarding Against Common Errors, provides excellent lessons learned from evaluation of GNE incidents.
6.1.2.3 Longitudinal Errors. Longitudinal errors, in the form of failure to provide updated ETAs, are another common navigation error and one that is easily preventable.
6.1.2.3.1 Deviations around weather can affect ETAs. ICAO Annex 2 requires you to provide ATC with an updated ETA when weather deviations cause the originally notified ETA to be inaccurate.
6.1.2.3.2 Per ICAO Annex 2, you must adhere to any assigned Mach number or airspeed. If you use Long Range Cruise (LRC) or Economy (ECON) modes, you are operating in a constantly changing speed mode. Flying in these modes may not be compatible with maintaining a fixed ATC speed assignment.
6.1.2.3.3 When position reports are made by voice, ICAO Annex 2 requires you to report to ATS any change to your ETA in excess of 2 minutes, both for your initial oceanic entry point as well as all required reporting points along your route of flight. (In the NAT region, the allowance for revised estimates is “3 minutes or more.”)
6.1.2.3.4 Discrepant wind data can result in inaccurate ETA computations. This can be particularly problematic if you are not flying at the flight-planned altitude or have outdated winds loaded in your navigation system. You must diligently monitor your ETA and maintain your assigned Mach number in order to minimize these errors.
6.1.2.3.5 Navigation system-computed ETAs, particularly for more distant waypoints, may be erroneous due to down track wind conditions, which the navigation system is not presently using to compute the ETA. You should compare navigation system estimates with the ETA calculated using the OFP prior to reporting the ETA to ATC.
6.1.2.3.6 Automatic position reports delivered via ADS-C have greatly reduced the occurrence of longitudinal errors caused by inaccurate ETAs. ATC establishes an ADS-C periodic report interval appropriate for the longitudinal and lateral
6-5 separation criteria being used. More frequent reports compensate for wind discrepancies and provide ATC with accurate ETAs.
6.2 Flight Plan.
6.2.1 A TC Flight Plan .
6.2.1.1 ICAO Annex 2 requires you to file a flight plan for any flight that crosses international borders. IFR operations in oceanic airspace generally start at 6,000 feet. VFR operations at or below 5,500 feet must comply with all applicable regulations and foreign airspace requirements.
6.2.1.1.1 Even though you may legally conduct flights in oceanic and remote continental airspace under VFR, you will likely encounter instrument meteorological conditions (IMC) at some point in your flight.
6.2.1.1.2 We therefore recommend that you file and fly under IFR on all oceanic flights.
6.2.1.2 Proper completion of an ATC flight plan relies on detailed knowledge of the airspace you intend to transit, the airspace equipment requirements, and the required FAA authorizations (OpSpecs/MSpecs/LOAs). You also need to be thoroughly familiar with the equipment your aircraft has on board as listed in your filed flight plan. When you file, your flight plan is transmitted to ATS facilities along the route of flight. If you do not file correctly, you could possibly experience delays before takeoff for an issue with an ATS authority along your route of flight.
6.2.1.2.1 The AIM has a step-by-step description detailing how to complete FAA Form 7233-4, Pre-F light Pilot Checklist and International Flight Plan.
6.2.1.3 As Performance-based Navigation (PBN) and PBCS become more prevalent worldwide, ATS authorities will increasingly set aside certain airspace for compliant aircraft. You list your aircraft and crew capabilities using descriptors in items 10A, 10B, and 18 of the flight plan.
Note: Without the proper codes or remarks identifying the operational approvals of your crew and aircraft, controllers may deny you en route climbs to your most fuel-efficient FLs or access to the optimum routings or, in some cases, reject your flight plan entirely.
6.2.1.4 Title 14 CFR part 121 dispatch services have staff knowledgeable in all filing requirements for both domestic and international operations. These services can support flight plan reroutes that may arise due to weather or congestion along the route of flight. Regardless of whether you are operating with a dispatch service, you must comply with 14 CFR part 91, § 91.103, which requires pilots to “become familiar with all available information” concerning a flight. Pilots should have the knowledge and necessary tools available to
6-6 react to unplanned reroutes, equipment failures, or emergencies that may affect a flight while en route. Operators using commercial vendor flight planning services remain responsible for all aspects of the flight.
6.2.2 E quipment Capability Codes —Flight Plan.
6.2.2.1 PBN and PBCS are changing the way ATS providers apply separation criteria between aircraft. Without notifying the crew of either aircraft involved, ATS providers in “mixed mandate” airspace can reduce separation between aircraft based on your stated capability. In order to take advantage of opportunities for more efficient routings, your flight plan should reflect the lowest (i.e., the best) RNP, RCP, and RSP values for which you are capable and authorized.
You must only use codes for equipment that is installed and operable.
Similarly, you must only use capability codes that reflect your actual authorizations, when authorization is required. You must have a specific approval (OpSpec/MSpec/LOA) to indicate RNP 2, 4, or 10 capability on your flight plan.17 Conversely, you do not require an LOA for RNAV 1 or 2.
6.2.2.2 The absence of equipment or capability codes in your flight plan (e.g. for RNP, RSP, RCP, ADS-C, ADS-B, CPDLC, RVSM, etc.) informs ATC that your aircraft is either not equipped with or authorized to use such capabilities.
The presence or absence of equipment and capability codes affects route and altitude assignments, as well as separation differences with other aircraft. You should ensure your flight plan reflects all the codes, as per flight plan guidance in the AIM, applicable to your aircraft equipment and authorizations.
6.2.2.3 The RNAV/RNP, RCP, or RSP capability indicated on your flight plan must not be better than that for which you have been approved via an OpSpec, MSpec, or LOA, as applicable. For example, if you have only been approved RNAV/RNP 10 (code A1), you must not indicate RNP 4 capability (code L1).
6.3 Aircraft Preflight Guidance.
6.3.1 P reflight— Necessary Documents. Effective oceanic and remote continental airspace flight planning and execution requires a number of important pieces of information. You should ensure you have easy access to the following documents/information in the cockpit, as well as others that may be pertinent to your flight:
6.3.1.1 M aster flight plan (“Master Document”).
Note: Use strict procedures to manage the Master Document. Maintain only one OFP labeled “master” in the cockpit.
17 Regulatory reference is § 91.169, which refers to § 91.153. This requires the flight plan to include “any other information the pilot in command or ATC believes is necessary for ATC purposes.” The U.S. AIP states that pilots must “advise ATC” if equipment failures render the filed capability indicators inaccurate.
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6.3.1.2 NOTAMs for departure, destination, alternate(s), ETOPS alternates (as applicable), and applicable FIRs.
6.3.1.3 G PS NOTAMs (as applicable).
6.3.1.4 Weather for departure, destination, alternate airports along the route of flight, and ETOPS alternates (as applicable).
6.3.1.5 SIGWX chart.
6.3.1.6 Wind charts for planned altitudes and altitudes after driftdown/emergency descent.
Note: Compute ETPs for contingencies, such as medical divert, engine loss, rapid decompression (RD), and a simultaneous RD and engine loss. Note the location of the ETPs on your plotting/orientation chart.
6.3.1.7 Space weather: solar flare information (see the National Oceanic and Atmospheric Administration’s (NOAA) website at https://www.swpc.noaa.gov/forecasts).
6.3.1.8 Volcanic ash information (as applicable).
6.3.1.9 Pilot Weather Reports (PIREP).
6.3.1.10 Receiver autonomous integrity monitoring (RAIM) and fault detection and exclusion (FDE) prediction tools (for GNSS and RNP operations), available at https://sapt.faa.gov/default.php.
6.3.1.11 Current track message (for any operations in airspace with a flexible organized track system (OTS)).
Note: If you have a track message or other separate route document associated with the flight, verify that the effective time of the message corresponds to your flight and that the designated route agrees with both your filed routing and the waypoint routing on your Master Document.
6.3.1.12 Plotting/orientation chart.
6.3.1.12.1 You should use an oceanic plotting/orientation chart, of appropriate scale, and with latitude and longitude depicted, to provide a visual presentation of your intended route, regardless of your type(s) of LRNS and method of cross-checking aircraft position. Plotting your route on a chart helps with situational awareness, and (together with the OFP) also helps with navigation contingencies such as DR, in the event of navigation system degradation/failure.
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6.3.1.12.2 Your chart should include, at a minimum:
1. The route of your filed flight plan. If your cleared route differs from what you filed, your currently effective route clearance.
2. Clearly depicted waypoints using standardized symbology.
3. All ETPs, plotted on the chart (with relation to the route).
4. Alternate airports.
5. Proximity of other adjacent tracks.
6.3.1.12.3 Figure 6-1 shows a sample plotting chart for an eastbound flight on a random route in the North Atlantic at FL 410. Note that the westbound tracks are plotted north of the route of flight, for situational awareness.
Figure 6-1. Sample Plotting Chart N ote: For certificated operators, if you hold OpSpec/MSpec A061, Electronic Flight Bag (EFB) Program, authorizing use of an EFB, the principal inspector (PI) can authorize “interactive plotting for oceanic and remote continental navigation,” ensuring the EFB application fulfils plotting/orientation chart requirements listed in paragraph 6.3.1.12. With this authorization, you can use your EFB application in place of a paper plotting/orientation chart. AC 120-76, Authorization for Use of Electronic Flight Bags, provides guidance for operators to develop associated EFB procedures. Title 14 part 91
6-9 operators may use an EFB, provided they observe the criteria and considerations of AC 91-78, Use of Class 1 or Class 2 Electronic Flight Bag (EFB).
6.3.2 Cockpit Preparations.
Note: These procedures assume at least two pilots are on duty. Some aircraft are certified for single-pilot operations. If your intended flight in oceanic or remote airspace can safely accommodate single pilot operations, you should develop some methodology to check your clearance, waypoint entries, equipment setup, etc. It may be possible to involve non-flying crew in some checks, either prior to flight, or in-flight, via appropriate voice and/or data communications. Where such support is not available, single pilot procedures should be carefully designed to detect and fix errors promptly, thereby minimizing or altogether preventing deviations.
6.3.2.1 Check your maintenance log to ensure all your required communications, navigation, and surveillance and altimetry equipment is operational.
1. Consult your MEL to be fully familiar with operational procedures associated with any inoperative equipment, before you depart.
2. Inoperative equipment could affect the capabilities filed in the ATC flight plan. It is important to update the codes, as needed, to ensure ATC routes you in accordance with your capabilities.
3. A departure delay to accommodate repairs may be warranted.
Alternatively, a reroute to avoid oceanic airspace may be necessary.
6.3.2.2 Identify a single master clock in the cockpit.
1. Verify that your onboard primary time source, or master clock, is set to UTC. In most cases, this time source is the FMS.
2. Use master clock times for all ETAs and actual times of arrival (ATA).
6.3.2.3 Align your inertial navigation system (INS)/inertial reference system (IRS).
1. Proper INS/IRS loading and operating procedures are another important aspect to help you avoid navigation errors. Ensure you select navigation (NAV) mode at the appropriate time and properly manage your navigation computer during intermediate stops.
2. Carefully follow your inertial system flight manual procedures to ensure proper navigation reliability.
6.3.2.4 Have a second pilot independently verify the aircraft present position coordinates you have loaded in your navigation system.
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1. Both pilots should verify the present position in the LRNS. Aircraft maintenance or towing can cause the present position suggested on initialization to be incorrect.
2. If you conduct another present position check on taxi out and it shows a gross difference from your gate coordinates, it could indicate a problem with the LRNS.
6.3.2.5 Two pilots should independently coordinate the loading and verification of all flight plan entries. One pilot should load the entire route into the LRNS, to include all waypoints, using the Master Document as source. He or she should then verify the routing has been loaded correctly. Below are recommended steps for performing this loading and verification. The second pilot’s subsequent confirmation procedures are explained beginning in paragraph 6.3.2.6.
6.3.2.5.1 Prior to loading the flight plan, carefully cross-check the waypoint routing on your Master Document against your filed flight plan to verify both documents show the same routing.
6.3.2.5.2 Ensure your navigation database and FMS software version are current and correct.
6.3.2.5.3 For systems with pilot-defined waypoint designators or numbers, we recommend you use a consistent procedure. Enter this designator on the Master Document and use it to store waypoints in the navigation computer.
6.3.2.5.4 Verify all navigational information contained in the Master Document against the navigation data information in the navigation system.
6.3.2.5.5 Your procedures should provide for a means of verification of the data you loaded. You should check the expanded coordinates and course/distance between waypoints against the same information on your Master Document.
You may also check the route presentation on your navigation display. Most long-range aircraft have a navigation system that is capable of automatically uplinking flight plans sent from ATC or from a dispatch service. These “push to load” flight plan uplinks are very reliable, but there are occasional glitches that can lead to loading partial routes, requiring you to make changes to complete the route load. Regardless of how you load your flight plan into your navigation system, you should have procedures to verify your flight plan route against your navigation system entries.
6.3.2.6 After the first pilot has loaded and verified the navigation system entries against the flight plan, a second pilot should recall and confirm the waypoint data against source information.
6.3.2.6.1 It is not sufficient for one crewmember simply to observe another crewmember entering the data. You should use an independent cross-check
6-11 method between pilots so no navigation system entry goes unverified. An attitude of “healthy suspicion” can facilitate good cross-checks.
6.3.2.6.2 Cross-checks should include comparing the expanded coordinates of the waypoints loaded in the navigation system to the filed flight plan, track message (if applicable), and the Master Document.
6.3.2.6.3 Verify the total route distance in your navigation system against your Master Document to help find embedded mistakes. Also cross-check course/headings and distances between each waypoint to ensure the navigation system routing matches your Master Document. Referencing your plotting or orientation chart here can also be beneficial.
6.3.2.6.4 A 1° course deviation causes the aircraft to be off planned routing by approximately 1 mile every 60 miles of travel. A course deviation on an oceanic crossing closer to the equator, where leg lengths are typically longer, can result in cumulatively larger displacements from course. However, although leg lengths are typically shorter at higher latitudes, and similar deviations result in cumulatively smaller displacements from course, the density of traffic and closer spacing of parallel tracks at high northern latitudes actually constitute an environment less tolerant of course deviations.
6.3.2.6.5 The second pilot should work from the navigation system back to the Master Document (i.e., by reading what is in the navigation system, and comparing that with what is in the Master Document). Reading from the Master Document to the navigation system can result in “seeing what we expect to see” (expectation bias). A simple way to consider this is that the first pilot works from “paper to glass” while the second pilot works from “glass to paper.”
6.3.2.7 Adopt appropriate annotations to indicate the status of each waypoint listed on the Master Document. For example:
1. The first pilot could put a circle next to the waypoint, waypoint number, or symbol on the Master Document to signify that they have independently cross-checked the entry of the coordinates in the navigation computer.
2. The second pilot could then tick or diagonally slash the circle next to the waypoint, waypoint number, or symbol to signify having performed the cross-check described above, to include confirming the course and distance information within a specified tolerance (e.g., plus or minus 2° and 2 NM).
6.3.2.7.1 We discuss additional Master Document symbology in the en route section, in paragraph 6.4.
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6.3.2.8 Set the appropriate mode select secondary radar with data link (Mode S) flight identification (FLT ID), which should correspond verbatim to the Aircraft Identification (ACID) (call sign) entered in Block 7 of the ATC flight plan.
6.3.2.8.1 ATC systems worldwide are becoming more reliant upon information transmitted by Mode S transponders to manage air traffic. ATC systems use transmitted FLT IDs to uniquely identify each aircraft within a given airspace and correlate them to a filed flight plan for the provision of surveillance and separation services.
6.3.2.8.2 A FLT ID is comprised of a maximum of seven alphanumeric characters
(e.g., N235RA, AAL3342, BONGO33) and must agree, verbatim, with the ACID entered in block 7 of the ATC flight plan.
6.3.2.8.3 You typically enter your FLT ID through either an FMS interface or your transponder control panel. For ATC systems to function correctly, you must ensure the FLT ID you enter in the FMS exactly matches the ACID in block 7 of the ATC flight plan.
6.3.2.9 Check your ground speed in the blocks and on taxi out.
1. If you are still in the blocks and your ground speed reads other than zero, you may have a developing error in your LRNS.
2. Similarly, if your groundspeed on taxi out appears unreasonable, this may also indicate a problem with your LRNS.
6.3.2.10 Accomplish required RVSM altimetry ground checks.
6.3.2.10.1 Before taxi, set your altimeters to the airport local altimeter setting. Both primary altimeters should read within ± 75 feet of a known elevation
(e.g., field elevation).
6.3.2.10.2 The two primary altimeters must also agree with each other within the limits noted in the aircraft operating manual.
6.4 En Route Guidance.
6.4.1 Oceanic Clearance: How to Request, Receive, and Process.
6.4.1.1 Oceanic clearances are unique clearances that frequently require coordination between two or more air traffic agencies. The clearance you receive from an ATC facility on the ground before departure may not constitute a clearance into or through your filed oceanic and remote continental airspace. Depending on the first oceanic FIR you enter, you may need to obtain this clearance separately and specifically as you approach that airspace. Check the AIP (or other relevant source document) to determine if such separate oceanic clearance is required.