Reminds Operators Of The Importance Of Following Appropriate Procedures When Amending An Air Traffic Services (ATS) Flight Plan

The FAA Air Traffic Organization (ATO), along with the Flight Standards Service (AFS), has noticed an increasing trend with discrepancies between the “filed” ATS flight plan and the “operational” flight plan provided to the flightcrew. These discrepancies can lead to a loss of separation and an increase in workload for Air Traffic Control (ATC) and flightcrew(s).

The agency cites the following examples: During July 2014—Hours after departing JFK, ATC noticed a B77W flying a route that differed from the flight plan. While ATC had cleared the flight as filed based on the most recent flight plan, Dispatch had issued the pilot a route from an earlier filed flight plan. Then, during August 2014—ATC provided a C525 1000’ vertical separation in Reduced Vertical Separation Minimum (RVSM) airspace based on the ATS flight plan. However, the operational flight plan indicated the flight was not RVSM approved.

Despite efforts to correct this problem, including monthly meetings between the FAA ATO and flight plan filers, flight plan discrepancy errors have continued.

According to the agency, the majority of flight plan discrepancies appear to be caused by inadequate coordination of changes to flight plans. The most common types of problems seen include:

• Sending of a “replacement” flight plan without canceling the original flight plan.
• Sending a “replacement” flight plan after an attempt to cancel the original flight plan was unsuccessful (usually because the attempt to cancel occurred after the departure strip printed).

Either of the above cases results in multiple flight plans in the system. ATC will resolve these when aware of them, but there are cases (especially if the change is made very late) where ATC will not see the second flight strip in time. In a busy tower with parallel runways, the strips may even be distributed to different positions.

Flight plan changes are the leading cause of FMS input errors resulting in navigation errors. Such errors can be eliminated by enforcing the appropriate filing procedures.

Acceptable operator procedures may vary depending on whether they normally amend flight plans or cancel/refile, but in any case the following constraints must be addressed, since FAA systems do not allow any operator changes once the first departure strip prints, normally 45 minutes before the proposed departure time.

If a flight plan is amended more than 45 minutes prior to the filed, proposed departure time, the aircraft dispatcher or flight planner can send a “Change” message. If the change involves a route change, the filer has the option to send a “Cancellation” message first, wait for an acknowledgement from the system, and then refile the flight plan accordingly. If there is any uncertainty whether the cancellation has been processed or if you cannot send a Cancellation message, then call Flight Data at the ARTCC and ask them to remove the flight plan. If the response to a cancel or change message is “REJECT- MANUAL COORDINATION REQUIRED” this means the system has locked the flight plan from user amendments and you must call the center.

If any change occurs within 45 minutes of the proposed departure time, the recommended procedure is to request the controlling facility remove the current flight plan and inform them that the dispatcher or flight planner will be filing a new flight plan. When informed that the flight plan has been removed, the dispatcher should send the revised flight plan to the center. Dispatch can coordinate directly with the controlling facility when the pilot is known to be not yet in contact with ATC. The pilot and ATC must be part of the change coordination once they are in communication. Regardless of when and how the change is made, dispatch must take steps to ensure that any change communicated to the pilot is successfully coordinated with the controlling facility.

The FAA recommends that affected operators familiarize themselves with the information contained in this InFO and ensure procedures are established for flight plan amendments to eliminate the chance of having conflicting, or multiple operational and ATS flight plans. Flight planning information is available at the FAA Flight Planning website.

FMI: InFO