The OIS application provides air traffic specialists with a central source for information on air traffic flow-related information across Canada, and in major U.S. centres.
Developed and maintained by NAV CANADA, OIS provides up-to-the-minute information in the following categories (referred to as “grids”):
For more information on any of these types of entries, click on the corresponding section link.
Issues are entered into the appropriate categories as soon as they are reported to NAV CANADA, and updated as new information becomes available. Entries are automatically removed from the display once the End time has passed, except for those grids that have an “Expected End Time” (i.e., Outages and Flight Checks; these should be removed manually by an Administrator).
A Ground Delay/Airspace Flow Program (GDP/AFP) is implemented to control air traffic volume to an airport where the projected traffic demand is expected to exceed the airport's acceptance rate for a lengthy period of time. Lengthy periods of demand exceeding acceptance rate are normally a result of the airport's acceptance rate being reduced for some reason. The most common reason for a reduction in acceptance rate is adverse weather such as low ceilings and visibility.
The OIS grid for GDP/AFP contains the following information:
- Location, the location that is affected
- Start time of the GDP/AFP (in UTC time)
- End time (estimated, in UTC time)
- Scope, which describes the area(s) affected
- Reason, what caused the GDP/AFP; common reasons include:
o Construction
o Runway closure
o Volume
o Weather
o Wx, Const (weather and construction)
o Wx, TSTMS (weather, thunderstorms)
- ADVZY No., the advisory number related to the GDP/AFP, which is supplied from one of two sources:
o The Federal Aviation Authority (U.S.); or
o NAV CANADA.
Flights that are destined to the affected airport are issued Estimated Departure Clearance Times (EDCTs) at their point of departure. Flights that have been issued EDCTs are not permitted to depart until their Controlled Departure Time (plus or minus 5 minutes). These EDCTs are calculated in such a way as to meter the rate that traffic arrives at the affected airport; ensuring that demand is equal to acceptance rate. The length of delays that result from the implementation of a Ground Delay/Airspace Flow Program is a factor of two things; how much greater than the acceptance rate the original demand was, and for what length of time the original demand was expected to exceed the acceptance rate.
Ground Stops are set by an airport
that is experiencing anticipated arrival rates that exceed capacity. Ground
Stops are implemented for a number of reasons, the most common of which are:
- To control air traffic volume to airports when the projected traffic demand is expected to exceed the airport's acceptance rate for a short period of time.
- To temporarily stop traffic to allow time for the implementation of a longer-term solution, such as a Ground Delay/Airspace Flow Program.
- The affected airport's acceptance rate has been reduced to zero.
The OIS grid for Ground Stops contains the following information:
- APRT, the airport that is affected (using international ICAO codes)
- Start time of the Ground Stop (in UTC time)
- End time (estimated, in UTC time)
- Scope, which describes the area(s) affected
- Reason, what caused the Ground Stop; common reasons include:
o Construction
o Runway closure
o Volume
o Weather
o Wx, Const (weather and construction)
o Wx, TSTMS (weather, thunderstorms)
- ADVZY No., the advisory number related to the Ground Stop, which is issued by one of two sources:
o The Federal Aviation Authority (U.S.); or
o NAV CANADA.
When you click on the ADVZY No., a pop-up window will appear with the full text of the Advisory, as published by the issuing source.
Flights that are destined for an airport with a Ground Stop program in effect will be held at their point of departure until the end of the Ground Stop program.
A Restriction is a method of
controlling the flow of aircraft into a constrained area. Common types of
restrictions include:
- MIT (Miles in Trail): a specified number of miles between aircraft.
- MINIT (Minutes in Trail): a specified number of minutes between aircraft.
- Reroute: rerouting an aircraft.
The OIS grid for Restrictions contains the following information:
- Area, the area that is affected (e.g. ATC sector)
- Start time of the Restriction (in UTC time)
- End time of the Restriction (estimated, in UTC time)
- Details, information describing the nature of the Restriction
- Affected, the group of aircraft that are affected (e.g. CYYZ arrivals)
- Originating Unit, the unit that requires the Restriction
- Providing Unit, the unit providing the Restriction
- ADVZY No., the advisory number related to the Restriction, which is issued by one of two sources:
o The Federal Aviation Authority (U.S.); or
o
NAV CANADA.
Note that not all Restrictions have an associated advisory.
When you click on the ADVZY No., a pop-up window will appear with the full text of the Advisory, as published by the issuing source. Note that not all Restrictions have an associated Advisory.
MIT and MINIT meter the rate at which aircraft enter a particular area. Reroutes allow the movement of selected traffic away from a particular ATC sector or group of sectors due to weather, volume, or staffing.
Routes are issued when the FAA Strategic Command Centre requests alternate routes through Canadian airspace, normally due to volume and weather in U.S. airspace.
The OIS grid for Routes contains the following information:
- Route, the designated Route (an asterisk beside the Route indicates that it is a modified route, and the user should refer to the associated advisory for more detail)
- Start time that the aircraft will enter the Route (in UTC time)
- End time that the aircraft will leave the Route (estimated, in UTC time)
- MIT (Miles in Trail), the specified number of miles between aircraft
- Dep (Departure), aircraft departing from these airports are to flight plan via the Route
- Dest (Destination), aircraft destined to these airports are to flight plan via the Route
- ADVZY No., the advisory number related to the Route, which is issued by one of two sources:
o The Federal Aviation Authority (U.S.); or
o NAV CANADA.
When you click on the ADVZY No., a pop-up window will appear with the full text of the Advisory, as published by the issuing source.
Prior to the summer weather season, the FAA and NAV CANADA collaborate on a group of routes that may be used for weather avoidance (Severe Weather Avoidance Program – SWAP).
These routes are classified west or eastbound and numbered. They are then published in the FAA severe weather “National Playbook,” available by clicking the link on the page: www.fly.faa.gov/ois/
When severe weather causes congestion in U.S. airspace, and additional routes are needed, the FAA Command Centre will collaborate with NAV CANADA and customers to determine if the use of an alternative Route is desirable, and then implement it if required.
Outages are issued to describe important navigation (or other) equipment outages that may affect the Canadian airspace system (scheduled or otherwise).
The OIS grid for Outages contains the following information:
- Location, the location of the Outage
- Start date and time of the Outage (in UTC time)
- Expected End date and time of the Outage (estimated, in UTC time)
- Details, a description of the Outage
- NOTAM, the reference number of the related NOTAM
Flight Checks are used to test various types of equipment to ensure that they are operating as specified.
The OIS grid for Flight Checks contains the following information:
- Location, the location of the Flight Check
- Start date and time of the Flight Check (in UTC time)
- Expected End date and time of the Flight Check (estimated, in UTC time)
- Details, a description of the Flight Check
- NOTAM, the reference number of the related NOTAM
Flight Checks are typically issued after an equipment failure or outage, and carried out to confirm that the equipment/system is operating within established tolerance ranges.
The Miscellaneous grid contains information on air traffic flow-management issues that do not precisely fall into any of the other categories. These types of issues are rare.
The OIS grid for Miscellaneous contains a Details field that describes the issues.
The Cancelled Initiatives grid lists all entries that have expired or been cancelled in the last 30 minutes.
At 30 minutes passed an entry’s End time-stamp, it is removed from the Cancelled Initiatives grid.