Flight Path Tool - Frequently Asked Questions
Installation and Troubleshooting
Why do I need administrator
privileges to install Java Web Start on Windows?
Java Web Start needs to register the MIME type of its launch file with
the system registry. MIME types are mappings used to find the correct
application to handle particular file types. MIME stands for
"Multipurpose Internet Mail Extensions." It is a standard across the
Java Web Start's MIME entry identifies it as the
application to launch to handle Java Web Start applications like the
Flight Path Tool. The MIME type applies whenever you try to open or
browse to a file with the ".jnlp" extension which identifies itself as
What is the "Security Warning" that
comes up the first time I run the application?
There are several features of the Flight Path Tool which require access
to your system and network. To print, the Flight Path Tool needs access
to your local printer. To save and reload preferences, the Flight Path
Tool needs access to your local disk drive. To get its data, the Flight
Path Tool needs to make an outgoing connection across your network to
our data server. These are the kinds of things applications do all of
the time without warning you.
To ensure that you are downloading the real Flight
Path Tool, and not a malicious application, the executable files are
signed to authenticate them. The warning is Java Web Start's way of
telling you that you are downloading an application that requires
access to your system, and asking you to verify the application is
coming from where you expect it.
Why do I get an error about "Cannot load
flightpath.jar" using the latest Java 1.5.0?
There is a bug in the initial release of Java Web Start for Java 1.5.0
The bug prevents applications from downloading properly. The message
window that appears says "Unable to download flightpath.jar." The
Details of the error will reveal an exception of the type:
JNLPException[category: Download Error : Exception:
java.io.IOException: Stream closed. : LaunchDesc: null ]
Unfortunately, there is no workaround to this bug. It
has, however, been fixed by Sun and is scheduled to be included in
build 58 of Java 1.5.0. If you are experiencing this error, please
install the last stable release of Java (1.4.2).
It does not contain the bug.
Why does Java Web Start say the jar file is
Some web filtering products used on Microsoft Windows, such as NetNanny
and certain firewall programs, corrupt the digital signatures on
downloaded application files. This makes the downloaded files appear to
have been tampered with. For security reasons, Java Web Start then
refuses to run the downloaded application. The only solution is to turn
off the offending software, clear your Java Web Start cache, and
re-launch the Flight Path Tool application.
Why can't I start the Flight Path Tool
in my browser?
Besides various flavors of Linux, the Flight Path Tool Application has
only been tested on Windows XP running Internet Explorer 6.0. We cannot
guarantee the application will start on all combinations of OSs and
browsers, and, because of our security policy, we are not allowed to
run many of the combinations our users have installed (for example,
However, it is not necessary to use a browser to run
the Flight Path Tool! A browser is used only to locate the Flight Path
Tool, and to kick off Java Web Start. To run the Flight Path Tool
without a browser, download and install Java
Web Start, then once you have Java Web Start running, type the
following URL into the Java Web Start "Location"
What kind of hardware is required to run
Generally, we suggest a minimum of 500 MHz processor and 500 MB RAM
along with 1024x768 monitor setting. If using a 28.8 or 56K modem
internet connection, then expect the application (6.8 MB) to take up to
40 minutes to download the first time. Once downloaded, it does not get
downloaded again (until a new version is available). The response time
of the application (accessing data) will vary according to your
internet connection as well.