Wednesday, July 18, 2018
Transport Canada - Aviation Safety Letter The Life of a Flight Plan

The Life of a Flight Plan

by the Safety Management Planning and Analysis Division, Operational Support, NAV CANADA

A flight plan (or itinerary) serves two main purposes. First, it provides information to NAV CANADA, which facilitates planning for the provision of air traffic control (ATC) services. Second, and most important, it is the basis on which alerting service is provided to pilots.

A host of air traffic service (ATS) units are involved in the provision of alerting service, including flight service stations (FSS), flight information centres (FIC), control towers, and area control centres (ACC). Community aerodrome radio stations (CARS), which are not ATS units, are also involved in the provision of alerting service.

The transfer of information between these units is seamless to pilots. But to ATS, it is vitally important to know which unit is responsible for providing alerting service at a given point in time. Just as pilots have procedures for the safe transfer of control of the aircraft between crew members (“I have control” or “you have control”), ATS has procedures for ensuring that one unit has responsibility for alerting service.

The purpose of this article is to provide pilots with an overview of what happens to their flight plan at each stage of its life. Understanding how the system works can help pilots make it work better for them! 1

Over the course of its life, a flight plan can be filed, amended, cancelled, activated, changed (IFR vs. VFR), updated, closed, or it can become overdue.

To facilitate planning by ATS, pilots are requested to file their flight plan at least 30 min prior to their proposed departure time.

Once filed, flight plan messages are transmitted via the aeronautical fixed telecommunications network (AFTN) to units that will be providing advisory, control and alerting services. The AFTN interconnects Canadian ACCs, control towers, FSSs and FICs and other aeronautical facilities around the world.

IFR flight plans are transmitted to the ACC in the flight information region (FIR) where the departure aerodrome is located, so that the ACC can provide control and alerting services. They are then transmitted from one ACC to the next as the flight progresses, and each new ACC assumes responsibility for alerting service.

VFR flight plans are held by the FIC in the area of responsibility where the departure aerodrome is located, so that the FIC can provide alerting service. Then, when activated, they are transmitted to the FIC in the area of responsibility where the destination aerodrome is located. The receiving FIC assumes responsibility for alerting service when the activated flight plan is received.

When filing a flight plan electronically, it is expected that the person filing will be contactable by phone for 30 min after NAV CANADA receives the flight plan, in order to clarify any information.

Amended or cancelled
In Canada, a VFR flight plan is activated automatically at the proposed departure time or actual departure time when reported to an ATS unit, whichever is earlier. To avoid an unnecessary search, it is very important for pilots to notify ATS when their proposed flight is delayed or cancelled. This is particularly true at aerodromes where no ATS or CARS service is provided, as there is no way for ATS to know if the aircraft has departed.

Flight plans filed through a computer system (e.g. NAV CANADA’s Internet Flight Planning System, or the Direct User Access Terminal System [DUATS]) can only be cancelled or amended by phone call to or radio contact with an ATS unit.

As stated above, in Canada, a VFR flight plan is activated automatically at the proposed departure time unless ATS knows that the aircraft has not departed. It is good practice, however, for VFR pilots to contact the appropriate ATS unit and request that their flight plan be activated. An accurate departure time facilitates planning of ATS and ensures more timely alerting service, if required.

As things work a little bit differently in the U.S., pilots flying VFR from the U.S. to Canada should be aware that they must contact an American automated flight service station (AFSS) to have their flight plan activated.

Federal Aviation Administration (FAA) control towers and air route traffic control centers (ARTCC) do not pass VFR departure times or position reports on to the AFSS. Many VFR pilots have unwittingly violated the Canadian Aviation Regulations (CARs) by crossing the border without an active flight plan. In the U.S., filing a VFR flight plan does not mean it has been activated!

Changed (IFR vs. VFR)
ACCs provide alerting services to all IFR aircraft and to the VFR aircraft for which they are responsible. FICs provide alerting services for all other VFR aircraft.

In Canada, when an aircraft “cancels IFR,” it means cancelling IFR control service. It does not automatically cancel alerting services. The controller or specialist should inquire whether the pilot also intends to close the flight plan. If so, the pilot will be advised, “alerting services terminated,” and the flight plan will be closed.

If the pilot wishes to keep the flight plan (and associated alerting services) open, the ACC will retain alerting services. Pilots should be reminded that an arrival report would then be required to close their flight plan.

In general, when cancelling IFR, it is advisable to keep the flight plan open to take advantage of alerting services—just don’t forget to file an arrival report!

This is another example of where things work a little differently in the U.S. If IFR is cancelled in the U.S., or in Canadian airspace delegated to the FAA, alerting service may not follow the pilot into Canada. In such circumstances, the pilot is required to file a new VFR flight plan before crossing the border in order to comply with the regulations and to ensure that alerting service continues to be provided.

Aircraft on composite flight plans (e.g. part VFR, part IFR) have their alerting service managed by different units during the various parts of their flights. The ACC is responsible for the IFR portion, while the FIC is responsible for the VFR portion.

What this means for pilots is that, in circumstances where the flight is terminating with a VFR portion, they should be sure to keep the FIC advised of any delays or revised arrival times. In accordance with VFR procedures, pilots should also be sure to file an arrival report with the appropriate ATS unit.

The above also applies to aircraft flying controlled
VFR (CVFR) (VFR in Class B airspace). While a flight plan and departure message is sent to the appropriate ACC to allow control service to be provided, alerting service is provided in the same way as for a VFR flight. This means that updates and arrival reports should be provided to the appropriate ATS unit.

Since alerting service is based on information provided by the pilot, it is critically important for pilots to keep the ATS unit or CARS up to date regarding changes to their flight plan. Section RAC 3.7 of the Transport Canada Aeronautical Information Manual (TC AIM) outlines the specific CARs requirements for updating a flight plan.

Pilots can certainly understand the importance of providing an update whenever there is a change to when, or where, they expect somebody to come looking for them!

With the exception of pilots arriving IFR at aerodromes served by an ATS unit, pilots are required to file arrival reports in order to close a flight plan. Pilots arriving VFR at aerodromes served by an ATS unit should not assume that their flight plan will be closed. They may request that the unit close their flight plan. Otherwise, a phone call to or radio contact with the FIC at the remote communications outlet (RCO) after landing will save unnecessary search and rescue (SAR) action.

The specific time an aircraft becomes overdue will depend on whether the aircraft is IFR or VFR, whether it is on a flight plan or itinerary, and whether a SAR time has been indicated on the flight plan.

If an aircraft is overdue, the responsible ATS unit will initiate alerting service. This process will begin with a communications search—contacting ATS units, aerodromes and CARS along the proposed route of flight to see if they have communicated with the aircraft, and calling the contacts provided on the flight plan. This process will culminate with the notification of the joint rescue coordination centre (JRCC), which will dispatch the appropriate SAR resources.

We hope this article has provided a better understanding of how flight plans make their way through the system. For pilots, the message is simple: ensure your flight plan is complete and up to date and, particularly when flying VFR, ensure your flight plan is activated, updated as required, and closed with ATS!

1   Pilots should be fully familiar with Section RAC 3.6 of the Transport Canada Aeronautical Information Manual (TC AIM), which provides information to pilots with respect to the requirements for flight plans. The information in this article is intended to provide additional information on how flight plan data is handled from an ATS point of view.


0 #1 Guest 2010-05-28 22:33
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