Frequently Asked Questions (FAQ)

Aerodromes and Air Navigation

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Obstacle Marking and Lighting

  1. What is an obstacle?

    The CAR 601.23 provides criteria as to when an object is an obstacle to air navigation.  Basically that the object is an obstacle if ....

    • it is higher than 90m AGL and located within 6km of the geographical centre of an aerodrome;
    • it is higher than 90m AGL and is located within 3.7km of the centreline of a recognized VFR route; or
    • it is higher than 150m AGL

    An object may also be an obstacle if it penetrates an airport obstacle limitation surface as detailed in Standard TP 312 Aerodrome Standards and Recommended Practices.

    Further, an object may also be deemed an obstacle, if so determined by Transport Canada.  Refer CAR 601.25

  2. Who should I notify if putting up an object that may be an obstacle?

    Notification should be given to the Regional office of Transport Canada. Notification should be through the Aeronautical Assessment Form for Obstruction Marking and Lighting which is Appendix C to Standard 621.

    Notification should also be given for NAV CANADA's Land Use Program.  NAV CANADA is primarily concerned about communication and radar interference.

    A notification is required to Transport Canada Marine Administration when the object is to be located offshore or on navigable waterways.

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