Navigation Worksheet

International Operations Manual

Eddie sez:

If you get a re-clearance that is significantly different than what is on your master document, you will need to update the master document, get a new one sent to you, or you will have to compute a new one on your own. The math isn't that hard, but you are likely to be in a rush when this happens and that means you will be prone to making math errors. You should carry a supply of blank navigation worksheets on every oceanic flight. You can download a blank copy: Navigation Worksheet (Blank). Now that you have the worksheet, here are your options.

  1. If you have an Internet connection, have your flight planning service send you a new flight plan.
  2. If you have a fax machine, have them fax it to you.
  3. Got a phone? Have them read off the pertinent information. You don't need the entire flight plan, just the oceanic portion that has changed.
  4. Failing all that, get your trusty calculator and plotter and be careful. More about how to do this: Reroute.

I've only had to do this a few times and each time it was with the plotter and circular slide rule. It was tedious and it was not as easy as I remember from my lieutenant days. The next time I will pick up the phone. Why bother? There are reports every month of a crew that got a re-clearance and ended up flying into the wrong airspace. It is nice having an accurate master document to check the electrons flying the jet.

Everything here is from the references shown below, with a few comments in an alternate color.

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The Requirement

[AC 91-70B, ¶D.2.5.7]

  • The number one scenario that leads to a pilot deviation from the assigned routing is a reclearance (that is different from the oceanic route requested with the filed flight plan).
  • You should be particularly cautious when receiving a reclearance.
  • Both pilots should separately copy and confirm the new routing, comparing with each other and confirming any inconsistencies with the ATS provider.
  • One pilot reprograms (and executes) your LRNS and updates the master document and plotting/orientation chart, crossing out the old waypoints and plotted route and replacing them with the updated information.
  • A second pilot cross-checks the newly effective route clearance with the reprogrammed route in the FMS (checking the expanded coordinates: degrees and minutes), the updated master document, and the updated chart.
  • You should check the magnetic course and distance between the new waypoints. To update the master document course and distance, use commercially available tables, or obtain from dispatch an updated master document. It is also possible to use an onboard flight planning system to independently calculate course and distance, and check that against the FMS.
  • Thoroughly brief all relief pilots on the new clearance prior to them assuming cockpit duties. We highly recommend the relief pilots also independently cross-check the currently effective route clearance against the FMS, master document, and chart.

[AC 91-70B, ¶] 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 FMS to reflect their currently effective route clearance. This can also result from a clearance or reclearance that was incorrectly entered, misread, or misunderstood. Procedures to follow in the event of a reclearance are included in paragraph Examples of scenarios that have led to GNEs are:

  • Poor management of the master document, resulting in crews not knowing the currently effective route clearance.
  • Incorrect waypoint entry procedures, particularly if the waypoints are not named and flightcrews must enter the full latitude and longitude.
  • Note: Waypoints entered via full latitude and longitude can produce misleading display names, where minutes are truncated or rounded and/or generic names are generated.

[AC 91-70B, ¶]

  • If the clearance is received via Controller-Pilot Data Link Communication (CPDLC), each pilot should read it silently to develop an independent understanding of the new clearance; they should then discuss the clearance and query the controller for clarification if they have any disagreement as to what the clearance is asking them to do.
  • Note 1: If you “accept” a clearance via CPDLC, the FAA recommends you also “execute” the new clearance in your FMS. Some crews have accepted, but not executed, a CPDLC clearance to avoid losing wind data or to preserve meaningful waypoint labels. Failure to “execute” the new clearance in the FMS could result in a navigation error and/or pilot deviation.

    Note 2: Reclearance via CPDLC has also been a factor in navigation errors associated with a route change. Operators should be cognizant of this when designing operating procedures for the use of CPDLC.

  • Thoroughly brief all relief pilots on the newly effective route clearance prior to them assuming cockpit duties.
  • Note: We highly recommend that the relief pilot(s) also cross-check the FMS against the master document to ensure complete understanding of the new clearance.


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