|The establishment or withdrawal of electronic
and other aids to air navigation and aerodromes
|New VOR added to charts, NDB removed, Fix name
changed, added or removed, etc.
|Changes in frequency, identification, orientation
and location of electronic aids to navigation
|There have been many NDB changes recently. Across
the country, single-letter NDBs serving as approach aids were recently
renamed to provide clarity for FMS systems, since many airports across
the country were served by the NDBs with the same single-letter name. All
of these sorts of changes could result in NOTAMs when not coincident with
|Interruptions in service or reliability, and the
return-to-normal operation of en route and terminal aids to navigation
|When NAVAIDs fail, are removed from service for
maintenance, or just the self-monitoring abilities of the device fail,
NOTAMs are issued both about the failure, and when they are returned to
|The establishment or withdrawal of, or significant
changes to, designated airspace or air traffic procedures and services
|Such things as the establishment of fire hazard
areas, temporary procedures and restrictions (for example, in the wake
of September 11) and other such items fall into this category.
|Significant changes in operations of runways and
serviceability of associated approach or runway lighting systems that could
prohibit or limit aircraft activities
|Airfield lighting failures can halt night-time
operation, or limit the ability for aircraft to see the runway in IFR conditions.
Also, construction activities frequently require personnel to work on or
near the runways, so instead of closing the runway, the airport authority
may close only a portion of it, making the shorter length available.
|The presence or removal of hazards that could
endanger air navigation or aircraft operations
|Temporary obstructions like a crane on a construction
site near an airport would be reported. Often, new approach minima for
the runways concerned will be published in this manner.
|Military exercises or manoeuvres and airspace
|The military often uses certain pieces of airspace
that are charted. On the charts, the designated areas are often noted as
"Mon-Fri, O/T by NOTAM". If this is one of those other times, then a NOTAM
will be issued regarding the area.
|The establishment or discontinuance of, or change
in, the status of Advisory or Restricted Areas
|New restricted areas are published by NOTAM to
get people's attention so they know about activities which may be dangerous
to flight. At the time of writing, the Moncton Flight College is rumored
to have applied to get an official status for their training areas. If established,
a NOTAM may be issued regarding these areas.
|Communication failures where no satisfactory alternate
frequency is available
|Failure of an FSS's RCO (remote communications
outlet) or an ACC's PAL (Peripheral) frequency, for example.
|Inaccuracies or omissions in publications that
might endanger aircraft operations
|Sometimes chart data is issued in error. NOTAMs
are issued to correct information on approach or en route charts. The next
cycle of publications will normally include information contained in these
|Failure of measuring and/or indicating systems
needed to supply current information on altimeter setting, surface wind,
RVR and cloud height for the pilot about to land or take-off
|Ceilometers (ceiling height), anemometers (wind
speed), transimissometers (runway visual range) and barometers (barometric
pressure, AKA altimeter setting) are available at many fields, but each
of these items are subject to their own failures. Ice storms frequently
cover up wind instruments and cause them to fail, for example, which may
lead personnel to underestimate winds, causing concern or danger.
|Any other information of direct operational significance
as recommended in Annex 15 to the Convention on International Civil Aviation
|This is the standard catch-all, attempting to
cover anything not specifically stated above.