Introduction
Welcome to
the user guide for the Australian General Aviation Trip Suggestion Utility.
I wrote this utility for a very simple reason. I like to fly general aviation
aircraft over relatively short distances in Australia – certainly no more than
500 nautical miles and usually far less than that. Typically, I like to plan a
flight that lasts approximately 60 – 75 minutes. If, for example, I am flying
the Piper Cub, I usually look for departure and destination airfields that are
no further than 30 – 50 nautical miles apart. That way I know I can fit in a
bit of sight seeing and still have the aircraft tied down before sunset.
The problem
- until now - has been finding all the possible flights that suit my particular
preferences. Certainly I could pull out a map and find a couple of airfields,
but instead I wanted my computer to examine every possible flight and then pick
a departure and destination point for me at random. More than that, I also
wanted to tell my computer how far I wanted to travel, whether I wanted to fly
around built-up areas, or whether I was happy to fly anywhere in the country.
What does the utility do?
Let’s say
you have a free couple of hours to fly, but you can’t decide where you want to
fly. Or, let’s say you wish to explore Australia more thoroughly in the
simulator, because up until now you’ve flown in the areas that are the most
familiar to you. Let the utility decide for you! You simply tell the utility
how far apart you want the departure and destination airfields to be. You can
also refine your search by enabling various options that will be discussed
later. Simply press the Find Trip button and seconds later, the utility
will give you the names, IDs, States and coordinates of the two airfields,
together with a precise listing of the official Australian aeronautical
chart(s) upon which the airfields are located. It also tells you exactly what
distance the flight would be if you flew in a “straight line” (otherwise known
as a great circle). You can then go ahead and create your flight plan in
the simulator the normal way.
What are the system
requirements for the utility?
You
require a licensed and fully functional copy of Microsoft Excel 2000 (version
9) or a later version of Microsoft Excel. Additionally, your screen resolution
must be set to at least 800 x 600 pixels. Higher resolutions also work fine,
but anything below 800 x 600 will not work because the user interface will be
larger than your screen area. You will also require a web browser (i.e
Microsoft Internet Explorer) or Microsoft Word 2000 (or later) in order to read
the comprehensive user manual. Apart from those requirements, any computer
capable of running Flight Simulator 2004 satisfactorily will also run this
utility without any problems. Of course, the slower your computer, the longer
the utility will take to produce an answer. My recommended specification would
be to use at least a 1.5 Ghz processor. With this sort of system specification,
the utility might typically take somewhere in the vicinity of 5 - 15 seconds to
produce an answer, with the utility being able to process around 150 flights
per second. That said, I've successfully tested it on a 250 Mhz machine, but I
had to set the search level to "Very Basic" if I did not wish to wait
too long. Bear in mind that you cannot interrupt the thought process of the
utility once it has started "thinking", so get a "feel" for
it first before becoming too optimistic with your control settings. A number of
options are included with the utility to speed up processing in the event you
own a slower computer and these will be discussed later.
Installation
The utility
does not require installation as such. Simply copy the supplied file trip_suggester.xls
to your desired folder. This can be any folder you like. You can even copy it
into your Flight Simulator 2004 folder if you wish. The utility is written in a
language called Vba, or Visual Basic for Applications. It runs natively under
Microsoft Excel, so you have to have Microsoft Excel open in order to run it.
Alternatively, you can simply create a shortcut directly to the utility on your
desktop. Then, when you click on this desktop shortcut, Microsoft Excel will
automatically open (if it is not already open) and the utility will
automatically start running. Also, if you run the utility from the desktop in
this way (and you are not currently using Excel for something unrelated) Excel
will also automatically shut down for you when you've finished with the
utility.
Because the
utility contains Vba macro code, you may encounter warning messages about macro
security when attempting to open trip_suggester.xls. In this event,
there are various ways to solve this problem. The simplest way is to disable
your macro security. Warning. By disabling macro security, you become
vulnerable to the possibility of your computer executing malicious Vba code
embedded in a file recognised by Microsoft Excel. If, however, you still
wish to do this in Microsoft Excel 2000, simply go to the top menu bar and
select Tools / Macro / Security. Then change the security level to Low.
An
alternative is to change your macro security to Medium. To do this in
Microsoft Excel 2000, simply go to the top menu bar and select Tools / Macro
/ Security. Then change the security level to Medium. At the Medium
security setting, Microsoft Excel gives you the opportunity to enable or
disable macros each time you open a file containing embedded Vba code. It is
then simply a matter of clicking once on the Enable Macros button
whenever you open trip_suggester.xls. If you feel you are vigilant and
responsible enough, then setting the security level to Low will prevent
any warning messages from being displayed. Your computer will, however, execute
Vba macro code without your approval and the results could be disastrous if the
Vba code is malicious. I therefore strongly recommend that the
security level be set to Medium and you put up with the extra mouse click
required.
Running the utility
As
mentioned earlier, to run the utility, simply ensure Microsoft Excel is open,
then open the file trip_suggester.xls. Alternatively, if you create a
shortcut to trip_suggester.xls on your computer desktop, then clicking
on that shortcut will start trip_suggester.xls automatically. If you run
into any problems or messages relating to macro security, please ensure you
have read and understood the contents of the previous section entitled Installation.
What do all the controls do?
The utility
interface is actually quite simple. Everything you need to run the utility and
view the results is clearly displayed on one screen. After you open the
utility, you will see a form as depicted below. Most of the controls are
located down the left-hand side of this form. These controls comprise 4
checkboxes, 3 rectangular text boxes (where you can control the distance
parameters) and 5 round radio buttons (that control the search depth of the
utility). On the right-hand side are two rectangular control buttons. The Find
Trip button actually starts the search process itself, after which the
utility automatically displays the results in the 5 long text boxes that appear
in the bottom half of the form. The Close and Exit button performs the
same function as the “X” in the top right-hand corner of the form. It simply
closes the utility down once you have finished with it.
The picture
of the Piper Cub invokes an “About” screen, which gives you some information
about the utility. It would be nice if you clicked on the picture of the Piper
Cub and read the contents at least once.
The last
feature of interest is the Distance Status display, located at the
bottom of the form. The utility will search for all possible flights inside
Australia that are within the distance specified in this display. The distance
shown has both a minimum and maximum value. The minimum and maximum values are
controlled by the values contained in the 3 rectangular text boxes on the
left-hand side. When you change the values in these 3 text boxes (using the
little spinner buttons on the right hand sides of these text boxes), you will
see the distance change in the Distance Status display.
The checkboxes explained
Departure
and Destination Airfields must appear on the same Chart. This parameter is useful if you
use real-world aeronautical charts when flying the simulator, particularly
electronic versions that you need to print. By checking this checkbox, you will
ensure that the departure and destination airfields for any chosen flight will
be located on one, single aeronautical chart only. This saves on printing time
and costs as well as reducing the amount of paperwork needed to undertake a
flight. If you do not use charts, or if you don’t care how many charts you will
require for a flight, leave this checkbox unchecked. If you check this
checkbox, it is important to note that in your search results, a number of
different charts may be listed for both the departure and destination
airfields. This is because many charts overlap each other, and some charts
cover the entire area of smaller, higher detailed charts. Even if this is the
case, you will always find that at least one of the charts listed will include
both airfields. It is then up to you to choose which chart you wish to use,
bearing in mind that the VTC is always the most detailed chart, followed by the
VNC and finally the WAC.
Exclude
International Airports from search. Realistically, I’m not going to be allowed to fly my Piper
Cub into Sydney International Airport, although in the simulator I can do
anything I like. If you wish to exclude International airports from the search,
check this checkbox. You might also check this checkbox if your computer has a
tendency to struggle with frame rates at International airports. I certainly
know mine does. On the other hand, if you leave this checkbox unchecked, then
any International airport in Australia is fair game for the utility search
engine.
Exclude
Complex Airports from search. This option was included to so as to exclude some of the
busier regional airports that – at least on my system – cause performance
degradation with more complex aircraft. For the purposes of this utility,
complex airports are separate to International airports, so if you wish to
exclude both, you need to ensure that both checkboxes are checked. Examples of
complex airports are Bankstown, Moorabbin and Essendon.
Restrict
flights to a single VTC area. As mentioned earlier, VTC (Visual Terminal Chart) areas
are typically high-traffic areas within the vicinity of larger urban centres
and air terminals (hence the name). If you check this checkbox, you certainly
won’t be getting a flight out in the middle of nowhere. In fact, geographically
speaking, you will miss out on what the vast majority of the country has to offer.
On the other hand, you will be flying in higher detail, built-up areas where
you are likely to see more AI traffic. You will often be flying in and out of
controlled airspace and are more likely to interact with ATC. If you use
real-world Visual Terminal Charts, you will already appreciate the high level
of detail they contain in comparison to other charts.
Changing the distance parameters
Firstly, I
think it is best to explain how distances work. In aviation, the shortest
distance between two points is known as a great circle route. Why use
the term circle instead of a straight line? It isn’t too hard to figure
out that because the earth isn’t flat, if you flew a long distance from one
place to another in a straight line, you’d first have to bore a very long
tunnel into the earth. The shortest route is actually a curved route positioned
vertically above this imaginary straight line. This route, called a great
circle, cuts the geoid-shaped earth in a circular arc connecting the two waypoints.
It should be noted that there is a very small difference in the distances
quoted by the utility as opposed to those quoted within Flight Simulator 2004.
The differences usually amount to a fraction of 1% (usually less than half a
nautical mile) and are on account of differing latitude and longitude reference
points used for the airfields in each individual application.
The most
obvious distance parameter in the utility is the Distance between Departure
and Destination airfields (in nautical miles). You can change this
parameter by placing your mouse pointer over the little spin buttons on the
right hand side of the text box and then clicking and holding down the mouse
button. The distance itself changes in 2 nautical mile increments. The lowest value
you can select is 4 nautical miles and the largest value you can select is 436
nautical miles. You can see the effect of clicking the spin buttons by watching
the Distance Status display near the bottom of the form.
Vary
maximum possible distance by this percentage. This is an additional adjustment that enables you
to increase the maximum search distance by a specified percentage. You may
increase the maximum distance between 5 and 15 percent. For example, if you had
entered a distance of 100 nautical miles and changed this percentage to 15, the
maximum possible search distance will become 115 nautical miles.
Vary
minimum possible distance by this percentage. This is an additional adjustment that enables you
to decrease the minimum search distance by a specified percentage. You may
decrease the minimum distance between -5 and -15 percent. For example, if you
had entered a distance of 100 nautical miles and changed this percentage to
-15, the minimum possible search distance will become 85 nautical miles.
As with the
actual distance adjustment itself, watch the Distance Status display
when making adjustments to these percentages.
One may ask
why I have designed the interface this way rather than let the user simply
enter the minimum and maximum search values. There are a few reasons for this,
but the main reason is to provide a very tight control over what values the
user is actually able to input, particularly in terms of restricting the
available range of distances that the utility is required to search through.
A very
important point to note is the effect of the changing these percentage values
upon the processing speed of the utility. Simply put, the greater the range
of distances the utility is asked to search, the longer it will take to arrive
at a result. For shorter distances, a large variation in percentages doesn’t
really create a particularly large variation between the minimum and maximum
distances. At greater distances, however, these same percentage changes can
create very large variances, resulting in the utility having to search through
tens of thousands of records. It is therefore recommended that the percentage
adjustments be used with care and commonsense, and that they be reduced as the
distance itself is increased. Otherwise, you may have to wait a while for the
utility to recommend a flight to you, because of the huge number of
calculations it needs to make.
The search parameters
The 5
different search settings control the maximum number of potential
flights that the utility can examine. At the Very Basic setting, a
maximum of only 100 possible flights are examined. At the Basic setting,
a maximum of only 500 flights are examined. At the Normal (default)
setting, a maximum of 1,500 flights are examined. At the Thorough
setting, a maximum of 5,000 flights are examined. At the Exhaustive
setting, a maximum of 12,000 flights are examined. It is important to note that
these figures apply to flights that have already satisfied the minimum and
maximum distances specified by the user. For example, if the user sets the
search to Basic, the utility may still read many thousands of records,
however once 500 of these records satisfy the user-input distance criteria, the
search is effectively called-off. The utility will then select a flight
randomly from those 500 flights selected. Of course, in those instances where
the number of possible flights is less than the maximum number permitted by the
user search setting, the search is called off immediately after all possibilities
have been examined.
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FAQ
Q. The utility is taking a very long
time to recommend a flight to me. What is wrong?
A. If you are searching for a longer
distance flight, make sure you reduce the percentage variances. The greater the
range of distances the utility has to search, the greater number of
possibilities the utility has to examine and subsequently process. Also, check
to see what search level you currently have selected. If the search level is
set to Thorough or Exhaustive, it may take a long while to
examine all the possibilities, particularly if you are trying to search over a
wide range of distances. You can always visually check the processing status of
the utility by referring to the Microsoft Excel status bar. The status
bar is located near the bottom of the screen. The information shown
includes the database currently being read, how many records have satisfied the
user-input distance criteria and how many records have been passed for
subsequent processing.
Q. The utility seems to only
recommend flights in Eastern Australia. Why is this so?
A. The utility prioritises its search
to Eastern Australia (NSW, QLD, VIC, TAS) followed by Western Australia (SA,
NT, WA). It then searches for possible flights linking Eastern and Western
Australia. If the search is cut short for any reason (such as the search level
being set to Very Basic or Basic), the search may be truncated
before the utility even begins to calculate Western Australia. In these
instances, try changing the search level to Thorough or even Exhaustive.
Also, you are probably being too optimistic in expecting the utility to examine
all possible flights over a large variety of distances. Try reducing the
percentage variations in the distance as well.
Q Why can’t I look for flights greater than 500
nautical miles?
A. It just comes down to the way I designed the
utility. I thought of several ways it could be done, but I wanted to keep the
utility reasonably simple so that the actual writing of it would be within my
somewhat limited capabilities. To increase distances beyond 500 nautical miles
would have required a completely different (and decidedly more complex)
approach to writing the utility.
Q. How come when I am trying to find a longer distance
flight, the utility keeps telling me it can’t find any flight at all?
A. Make sure the Departure and Destination
Airfields must appear on the same Chart checkbox and the Restrict flight
to a single VTC area checkbox are both unchecked.
Q. Why does the utility show sometimes show 5 or more
aeronautical charts associated with the recommended flight?
A. Sometimes the aeronautical charts
overlap each other. For example, the South-Western area of the VTC Sydney is
included in the North-Eastern area of the VTC Canberra. Additionally, the lower
detail WAC charts cover relatively large areas, which might also be partially
covered by a number of smaller, higher detail charts. Put simply, any
chart listed in the flight will definitely contain the corresponding airfield
listed. You can then choose which chart you wish to use from the list provided.
Q. The utility never seems to
recommend a flight from such-and-such an airfield. Why?
A. It might be because that airfield
information is not included in the utility. The utility only contains those
airfields that are listed in the stock version of Flight Simulator 2004, as
well as being listed in the June 2003 Enroute Supplement and the June
2003 Australian aeronautical charts. On the other hand, it might also simply be
a matter of chance. The utility randomly selects the flight from all possible
candidates. Sometimes there are only a few candidate flights to choose from;
sometimes there are many thousands.
Q. Can new airfields be added to the
utility and will the utility be updated?
A. Currently there are no plans for
this. To make the utility user-expandable would have required a considerable
increase in the program’s complexity and the use of a completely different
architecture.
Q. What’s all this talk about charts
and enroute supplements?
A. Aeronautical charts are sold to
pilots by Air Services Australia. Air Services Australia has a
website at http://www.airservices.gov.au/.
The VFR charts come in
three basic levels of detail. VTC (Visual Terminal Charts) are quite detailed
but only cover limited areas. The VNCs (Visual Nautical Charts) and WACs (World
Aeronautical Charts) are progressively less detailed but cover much larger
areas. I personally use electronic, printable versions of these charts that are
included in a real-world VFR flight planner called AirNav VFR. This
Windows-based flight planner is available from Sentient Software based
in Melbourne (telephone 03 9646 0231). Sentient Software also has a
website at http://www.sentientsoftware.com.au/.
The Enroute
Supplement, better-known as the ERSA, is available from Air Services
Australia. It contains a lot of detail about most airfields in Australia
and it is updated frequently. It is perhaps not as necessary for Flight
Simulator as it once was, as the new Garmin GPS in Flight Simulator 2004
provides much, if not all, of the necessary information with just a few mouse
clicks.
It should
be pointed out that it is not necessary to possess aeronautical charts
(or the ERSA) in order to use this utility. The features relating to the charts
have simply been included for the sake of those individuals who choose to use
them.
Q. How do I get support for this
utility if I run into problems?
A. You are not likely to run into
problems if you have read the manual and your computer meets the system
requirements. If you believe there is a particular issue that impacts the
essential functionality of the utility (and is not explained in this manual or
FAQ) you email me directly.
Q. Does Flight Simulator 2004 need to
be installed and / or running in order to use the utility?
A. No. The utility runs stand-alone,
but does require that you have Microsoft Excel 2000 (or later) installed on
your computer. Please refer to the section entitled What are the system
requirements for the utility? for further details.
Q. When I
run the utility I can’t do any other work in Excel at all. How can I fix this?
A. Sorry, but unfortunately that is “normal”
behaviour. It is simply one of the shortcomings of using modal forms in Visual
Basic for Applications. That said, you can still use other applications at the
same time. I suggest you just open the utility when you want to use it and
close it down when you’ve finished using it. Once it is cached for the first
time in your machine’s memory, it will open up very fast on subsequent uses.
Remember too, that if you already are doing work in Excel when you run the
utility, it will leave your work completely undisturbed when you close the
utility down.
Q. I don’t
want to have to start Microsoft Excel manually or shut down Microsoft Excel
manually every time I run the utility. Is there any way around this?
A. Yes.
Simply create a shortcut on your computer desktop that points directly to the
utility (point the shortcut directly to the file named trip_suggester.xls).
If you then run the utility from this desktop shortcut, Microsoft Excel will
automatically open and the utility will automatically start. Then when you’ve
finished with the utility, not only will the utility automatically shut down,
but Microsoft Excel will automatically shut down as well. If, however, you
already have Microsoft Excel open to start with, then the utility assumes you
want to keep it open when you’ve finished with the utility. So in this latter,
case, only the utility will shut down.
Q. I
thought you just said that the utility will automatically shut down Microsoft
Excel if I run it from the desktop. But I just saw the utility close down
Microsoft Excel and I did not run the utility it from the desktop.
A. The
utility has some logic in it that checks to see what work you currently have
open in Microsoft Excel. When you start the utility, if it finds any currently
open workbooks (even temporary ones like “book1”, etc), then it assumes you are
doing some sort of work in Microsoft Excel and won’t attempt to shut it down
when you go to close the utility. On the other hand, if you already have
Microsoft Excel open but do not have any workbooks open at the time you run the
utility, then the utility assumes it is safe to shut down Excel when you’ve
finished with it. (Note: The utility treats unsaved workbooks such as “book1”,
“book2”, etc as open workbooks).
If you
don’t want the utility to shut an already-opened copy of Microsoft Excel down
every time the utility runs, then simply make sure you have at least one
spreadsheet opened beforehand, even if it is nothing more than the default
“book1” blank sheet that usually opens when you start Microsoft Excel.
Q. I seem
to be having a problem displaying the tooltips on my multi-monitor setup. The
tooltips are displaying on a different monitor to that which I am using to run
the utility.
A. This is
an acknowledged issue. Hopefully you won’t find this to be excessively
annoying. I have developed an alternative version that uses Office Assistant
balloons to display the tooltips. However for various reasons I felt it was
preferable to upload this simpler version that uses the standard tooltips. If
for some reason the standard tooltips cause serious issues on multi-monitor
machines then I will upload the Office Assistant balloon version as an
alternative for people to try. My understanding, however, is that this problem
is more of a cosmetic annoyance than anything else.
Q. I was
wildly optimistic with my search settings and now the utility has plunged into
a long train of thought that I would like to interrupt.
A. Sorry,
by design the thought process is not interruptible, so I’d recommend you just
let it run through until it’s finished. The utility itself, the range of
parameters selectable by the user and the default settings were optimised for
machines around the 1.5 Ghz range. On such a machine at the default
configuration you should expect the utility to take up only 5 – 15 seconds to
come up with a trip suggestion.
Jonathan
Parle
October
2003
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