曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
mile for helicopters, and 1 mile for
everything else. You must also be
clear of cloud and able to maintain
visual reference with the surface, and
obtain clearance from ATC before
doing so, which means you must
have radios. Helicopters must also
fly slowly enough to avoid collisions
with other traffic or obstacles.
On your request (it is never
volunteered), permission will be
granted if traffic permits.
It may be authorised by a non-radar
equipped control tower and an FSS,
but remember that Special VFR only
applies in a control zone - although you
might be able to get to the edge of a
zone under it, you might not be able
to go further because the ½ mile
limit (for helicopters, anyway) may
increase to 1 mile outside the zone if
you cannot comply with low
visibility requirements.
IFR
Generally, all flights in IMC must be
conducted under IFR, although you
can actually fly under IFR at any
time, even if the weather is clear –
the essential difference between IFR
and VFR is that tighter margins are
applied for avoiding obstacles and
choosing your altitude according to
the direction you are flying in (the
Quadrantal Rule – see Cruising
Altitudes). In Class A, B, C, D, E or F
Special Use Advisory airspace, you
must also have ATC clearance, and
observe any conditions it includes.
IFR clearances must be read back,
except where a SID is in force and
you got the clearance on the ground
before departure, or you got it by
electronic means. However, ATC
may request a read back at any time.
You may deviate from clearances
and instructions as far as necessary
to avoid a collision, if you are
responding to an advisory from
ACAS or TCAS, or GPWS. As soon
as possible afterwards, however, you
must carry on with the last clearance
or instruction, and inform ATC of
what you’ve done.
Airspace Structure
The airspace over Canada is split up,
according to the use made of it.
Canadian Domestic Airspace (CDA)
This includes all airspace over the
Canadian land mass, the Arctic, the
Archipelago (assorted islands) and
any high seas underneath the bound:
82 Canadian Professional Pilot Studies
It is split into the Southern Domestic
Airspace (SDA) and Northern Domestic
Airspace (NDA). The difference
between them is that magnetic tracks
are used in the SDA, and true tracks
in the NDA. The above boundaries
are also used for:
Altimeter Setting Regions
The NDA boundaries (above)
coincide with the Standard Pressure
Region, where 29.92” is usually set on
the altimeter for altitude reference.
On departure within the region,
however, use the current altimeter
setting (from observations in the last
90 minutes) right up to the cruise
level, where you set 29.92” just
before reaching it. On arrival, just
before starting descent, use the
setting of the intended destination.
In the hold, keep the standard
setting until the lowest flight level in
the hold.
The Altimeter Setting Region is the
same size as the SDA, and is where
you must use the current setting of
the nearest station so, when landing,
set the altimeter to whatever is in use
at your destination.
When going from the ASR to the
SPR, set 29.92" immediately after
crossing the boundary, unless told
otherwise. When going the other
way, set the current altimeter setting
of the nearest station immediately
before crossing the boundary.
Airspace below 18,000 feet is Low
Level Airspace. Predictably, that from
18,000 feet upwards is called the
High Level Airspace.
High Level Controlled Airspace
This is divided into three areas, the
Southern Control Area corresponding
with the SDA, and the other two
fitting inside the NDA boundaries
(and therefore using True tracks),
being called the Northern and Arctic
Control Areas:
They start at FLs 230 and 280, so the
area below them (from 18,000 feet)
is uncontrolled (RAC 2.6).
Certain parts of high level airspace
need special equipment and
procedures to allow tighter
navigation and flight procedures for
reduced ATC separation, to make
better use of the airspace. For
example, the normal vertical
minimum was 2000 feet, until ways
were devised to reduce this safely to
1,000 feet with altimeters and heightkeeping
systems complying with
Reduced Vertical Separation Minima
(RSVM). Aircraft must be certified
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Canadian Professional Pilot Studies1(58)
