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
you know if you need one? Read on.
FAR 121.619 states that an alternate airport MUST be planned if from one hour before to one
hour after the estimated time of arrival the ceiling is forecast to be less than 2,000 feet, or the
visibility forecast to be less than 3 statute miles.
Remember this as the 1-2-3 Rule
1 1 hour before to 1 hour after ETA
2 Ceiling less than 2,000 feet
3 Visibility less than 3 statute miles
Alternate Airport
Radar Contact Flight Planning
Version 4 December 2, 2007
Copyright JDT LLC 2005 Page 99
Ceiling – The height above the earth‟s surface of the lowest layer of clouds or obscuring
phenomena that is reported as “broken”, “overcast”, “obscuration”, and not classified as
“thin”, or “partial”.
Now that we have determined that an alternate airport must legally be planned for our
destination how do you decide WHICH airport to plan?
Ideally you want to plan an alternate that is as close to the destination as possible for
economic and passenger convenience considerations, while at the same time remaining clear
of the weather that is requiring the alternate in the first place. This is not always an easy task,
especially during the winter months when widespread low ceilings and visibility are common.
In order to be able to legally plan to use an airport as an alternate under FAR part 121 the
forecast must indicate that it will meet the criteria for alternate airport weather minimums at
the estimated time of arrival.
Alternate airport minimums may be derived using the ONE NAV RULE or the TWO NAV
RULE from the table below.
Alternate Airport Weather Minimums
Approach Facility Configuration
Ceiling
Visibility
For airports with at least ONE operational navigational
facility providing an instrument approach
Add 400 feet to the
MDA or DH as
applicable
Add 1 statute mile to the
landing minimum
For airports with at least TWO operational navigation
facilities providing an instrument approach
Add 200 feet to the
higher DH or
MDA of the two
approaches used
Add ½ statute mile to the
higher authorized landing
minimum of the two
approaches used
Alternate Planning Tip: As a quick “rule of thumb”, if your planned alternate has at least two
ILS approaches with published minimums of 200 and ½ and each localizer has its own unique
frequency then your alternate minimums will be 400 and 1.
This means that the weather at your alternate anticipated ETA would need to be forecast with
a ceiling of at least 400 feet, and a visibility of at least 1 statute mile. If it does not, then you
will have to look for another alternate.
Radar Contact supports up to two alternate airports. How do you know if you need a second
alternate?
Anytime you see visibility forecast for less than the standard Category I ILS minimums of
200 and ½, then plan a second alternate. Just do not forget that your fuel will need to be
planned to the more distant of the two alternates.
Radar Contact Flight Planning
Version 4 December 2, 2007
Copyright JDT LLC 2005 Page 100
OK pilots, you are now briefed on how to construct a flight plan that will maximize your
enjoyment of Radar Contact. Any flight planning questions not covered in this manual may
be addressed on the Radar Contact Forum at AVSIM.
http://www.avsim.com/
Radar Contact Radar Contact User Interface
Version 4 December 2, 2007
Copyright JDT LLC 2005 Page 101
Radar Contact User Interface
Input Screens
Ok, you know about ATC now, how to plan a flight and how to get your flight plan ready for
use by Radar Contact. Now it is time to fire up the program. Locate RC in your start menu (a
shortcut to your desktop might be a good idea; you will be hooked before you know it), and
you will see this screen:
Load your Flight Plan
The first button to click is either one of the two on top: normally you would use the one
marked with FS200x (*.pln). If this is your first use of Radar Contact, browse to the directory
where your flight plans are saved. In FS2004, this is usually My Documents\Flight Simulator
files. FSX is usually the My Documents\Flight Simulator X files directory. RC remembers
the path to this directory, so you have to browse only this first time. Pick the flight plan you
prepared.
The other button on top, the one marked RCV2.x (*.apl), is meant for those people who had
prepared flights for use by Radar Contact version 2 or use FStarRC. If you have saved those
flights and wish to re-fly them with the new version, you can browse to the directory that
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
航空资料15(100)
