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
are coded in airborne navigation databases. The record
for a SID includes many of the same types of information that are found in the en route airway record,
and many other pieces of information that pertain
only to complex flight paths. Some examples of the
fields included in the SID record are the airport
identifier, SID identifier, transition identifier, turn
direction, recommended NAVAID, magnetic course,
and path/terminator.
MISCELLANEOUS RECORDS
There are several other types of records coded into airborne navigation databases, most of which deal with
airspace or communications. For example, there are
records for restricted airspace, airport minimum safe
altitudes, and grid minimum off route altitudes
(MORAs). These records have many individual and
unique fields that combine to describe the record’s subject. Some are used by avionics manufacturers, some
are not, depending on the individual capabilities of
each RNAV unit.
THE PATH/TERMINATOR CONCEPT
One of the most important concepts for pilots to learn
regarding the limitations of RNAV equipment has to do
with the way these systems deal with the
“Path/Terminator” field included in complex route
records.
The first RNAV systems were capable of only one type
of navigation: they could fly directly to a fix. This was
not a problem when operating in the en route environment in which airways are mostly made up of direct (or
very nearly direct) routes between fixes. The instrument approaches that were designed for RNAV also
presented no problem for these systems and the databases they used since they consisted mainly of GPS
overlay approaches that demanded only direct point-topoint navigation. The desire for RNAV equipment to
have the ability to follow more complicated flight paths
necessitated the development of the “Path/Terminator”
field that is included in complex route records.
There are currently 23 different Path/Terminators in the
ARINC 424 standard. They enable RNAV systems to
follow the complex paths that make up instrument
departures, arrivals, and approaches. They describe to
navigation avionics a path to be followed and the criteria that must be met before the path concludes and the
next path begins. One of the simplest and most common Path/Terminators is the track to a fix (TF), which
is used to define the great circle route between two
known points. [Figure A-7] Additional information on
Path/Terminator leg types is contained in Chapter 4.
The GRAND JUNCTION FOUR DEPARTURE for
Walker Field in Grand Junction, Colorado, provides a
good example of another type of Path/Terminator.
[Figure A-8 on page A-8] When this procedure is coded
into the navigation database, the person entering the
data into the records must identify the individual legs
of the flight path and then determine which type of
terminator should be used.
The first leg of the departure for Runway 11 is a climb
via runway heading to 6,000 feet mean sea level (MSL)
and then a climbing right turn direct to a fix. When this
is entered into the database, a heading to an altitude
(VA) value must be entered into the record’s
Path/Terminator field for the first leg of the departure
route. This Path/Terminator tells the avionics to provide
course guidance based on heading, until the aircraft
reaches 6,000 feet, and then the system begins providing
course guidance for the next leg. After reaching 6,000
feet, the procedure calls for a right turn direct to the
Grand Junction (JNC) VORTAC. This leg is coded into
the database using the Path/Terminator direct to a fix
(DF) value, which defines an unspecified track starting
from an undefined position to a specific database fix.
After reaching the JNC VORTAC the only
Path/Terminator value used in the procedure is a TF leg.
Another commonly used Path/Terminator value is
heading to a radial (VR). Figure A-9 on page A-9
shows the CHANNEL ONE DEPARTURE procedure
for Santa Ana, California. The first leg of the runway
19L/R procedure requires a climb on runway heading
until crossing the I-SNA 1 DME fix or the SLI R-118,
this leg must be coded into the database using the VR
value in the Path/Terminator field. After crossing the
TF Leg
Figure A-7. Path/Terminator. A Path/Terminator value of a TF
leg indicates a great circle track directly from one fix to the next.
A-8
I-SNA 1 DME fix or the SLI R-118, the avionics
should cycle to the next leg of the procedure that in
this case, is a climb on a heading of 175° until crossing SLI R-132. This leg is also coded with a VR
Path/Terminator. The next leg of the procedure consists of a heading of 200° until intercepting the SXC
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Instrument Procedures Handbook (IPH)仪表程序手册下(166)
