HDM's Instrumentation

HDM's Instrument Panel
HDM's simple, but highly effective instrument Panel.
HDMÕs Cambridge Basic Operation

These "Basic Operations" have been written to assist early users of
the Cambridge vario and navigation system.

HDMÕs CAMBRIDGE SYSTEM
The system is composed of two separate instruments, but which are
fully integrated:
i) the L-NAV vario and final glide computer
The L-NAV performs a number of functions - vario, averager, audio
output, winds and required altitude to a destination.
The L-NAV has two displays - the L-NAV itself, which is beside the
altimeter, and a small vario which is above and to its left (there
is also a small Winter mechanical vario which is to the left of the
L-NAV).
Although it is the L-NAV you will look at most in-flight providing
most of the information you need, it is rather the GPS/flight
recorder that you will use to navigate around a task.

ii) the GPS and flight recorder (datalogger)
The GPS/flight recorder measures and records latitude and longitude,
height and time. It also stores up to 250 way points (turn-points and
geographical locations).
The GPS/flight recorder allows for up-loading of pre-formated turn
points from a PC which has been done with HDMÕs instrument. It is
these turn points which will be used in these "Basic Operations".
The GPS/flight recorder has its own display in the instrument panel
above the L-NAV. Manipulation of tasks and turn points is done
through this display. The GPS/flight recorder is mounted on "velcro"
strips in
the baggage compartment behind the pilotÕs head (on the port side of
battery).
The GPS/flight recorder can be easily removed from HDM to allow your
record breaking flight to be down-loaded to a PC.

OTHER DOCUMENTATION
If the operations described in this document donÕt satisfy the needs of
the reader s(he) should refer to the GPS/flight recorder Manual and the
L-NAV Manual which is in the same folder as HDMÕs Flight Manual in the
GCV Office.

OPERATION
When you switch on HDMÕs Master switch the GPS/flight recorder is also
turned on. Turn on the L-NAV with the nob in its top left corner. Adjust
the speaker volume with this nob.
At Òpower-onÓ the Altimeter Screen is shown on the L-NAV after various
initialisation messages. Battery voltage is also shown on this screen.
Using the UP and DOWN buttons, change the barometric setting for the day
by adjusting the current altitude setting (QNH) to Benalla AirfieldÕs
altitude of 570 feet ASL. When finished setting the altimeter, press GO.
Move to the L-NAV Main Screen from the Altimeter Screen by pressing GO
twice.

CHOOSING A TASK
It is customary to enter, and set-up, the dayÕs task(s) before take-off.
Then as you proceed around a task you select the next turn point you are
heading for. We will follow this normal procedure.
You select tasks and turn points with the GPS/flight recorder display.
A task consists of three, or more, turn points (start, 1st TP, ..., finish).
Up to ten tasks (A-J) can be stored in the GPS/flight recorder. Each task
can have up to 9 turn points (0-8).
These ÒBasic OperationsÓ assume you are happy to use the turn points already
in HDMÕs flight recorder (Benalla NationalÕs turn points). We will describe
first how to select one of the existing tasks in the GPS/flight recorder
(the simplest operation) and then how to fly this task, changing the
destination turn point at the beginning of each leg. Towards the end of this
document we will descibe how to create, and edit, tasks.
Cambridge screens can be confusing, despite the manufacturer trying to make
them logical. On the GPS/flight recorder display, screens to the right of
the Main Screen are to do with the turn points of the current task. The right
most screen is the Task Selection screen.
Using the RIGHT button, on the GPS/flight recorder display, move to the right
six screens past the ÒLast PointÓ, ÒTask TPÓ, ÒTP: AlphabetÓ, ÒTP: DistanceÓ
and ÒLandpointsÓ screens to the ÒTask SelectionÓ screen. Press GO to enter
the Task Edit screens. ÒSelect Task AÓ is displayed together with the
distance around the task.
To view the turn points in a task, press RIGHT (and LEFT).
To view different tasks already existing in the GPS/flight recorder press UP
or DOWN. Press RIGHT (and LEFT) to view the turn points in a task. With the
task you have chosen displayed, e.g, ÒSelect Task CÓ, exit the Task Edit
screens by pressing GO. You will be given the option to declare and/or start
the displayed task before returning to the Main Screen.

DECLARING AND STARTING A TASK
A declared task has a date and time attached to it. The declared task is
attached to the Flight Log file in the PC. This permits Official Observers
to see if you declared your intensions before take-off.
For declaring the selected task the default setting is NO. Change between
NO and YES with the UP and DOWN keys. Press GO when the correct choice is
displayed (it doesnÕt hurt to declare the task even if youÕre not in a
competition, or not doing a badge flight). The display then queries if you
want to start the task. Again the default is NO. Change between NO and YES
with the UP and DOWN keys.
Starting the task at this point should not be confused with flying across
the start-line. It is more like starting the process for the GPS-NAV. The
GPS-NAV wonÕt display the task information in-flight (the ÒTask TPÓ screen
will display ÒNo Task is ActiveÓ) until you have started the task, so it is
best to select YES and then press GO. The display returns to the Main
Flying Screen and ÒOn Task TP:0Ó is displayed.

IN-FLIGHT USE OF THE CAMBRIDGE SYSTEM
The strength of the Cambridge system is that the two instruments are fully
integrated. The L-NAV takes its feed from the GPS/flight recorder. In
particular, the L-NAV displays the distance to the current turn point
selected in the GPS/flight recorder. Therefore, to change the L-NAV to the
next turn point, you do this with the GPS/flight recorder display.
Once airborne, but before you start a task, the GPS/flight recorder will
show the task start, i.e., Benalla, as the destination turn point. Once you
have crossed the start line, and are on task, you will want to change to
your first turn point. You change to the first turn point, and subsequent
ones, in the same way.
On the GPS/flight recorder display move to the right two screens
(pressing RIGHT) to the ÒTask TPÓ screen. This will show the next turn point
in the current task and the direction and distance to this turnpoint. Press
GO to make this turn point the current turn point. You will be taken back to
the Main Navigation Screen where the new turn point will be displayed.
The L-NAV will also now display the distance to the new turn-point. Simply
repeat this procedure as you turn a turn-point and head for the next.

CREATING A TASK
From the GPS-NAV Main Flying Screen move right 6 screens to the
"Task Selection" screen. Press GO to enter the Task Edit screens.
"Select Task A" will be displayed. Press DOWN repeatedly to view other
existing tasks until you come to a zero length task, say Task C.

Select Task
C

Dist    0.0
is displayed.
Press RIGHT. The following message is displayed:

Turnpoint C0
^ Select v

The ^ and the v are a hint to select a turn-point by using the UP and DOWN keys.
Turn-points are stored in alphabetical order. Use DOWN to reach turn-points
towards the beginning of the alphabet and UP to reach those towards the end.
NOTE: turn-point 0 is your start point which almost always will be
Benalla A/D so you should find Benalla first. When you have the desired
turn-point displayed, press RIGHT to begin selection of the next turn-point.
Repeat the previous two steps until all your turn-points have been entered.
When you have selected your last turn-point (the finish point) press GO to save
the task. Before being returned to the Main Flying Screen you will be presented
with a choice of declaring and/or starting the task (see "DECLARING AND STARTING
A TASK" above for an explanation of this).

EDITING A TASK
Modifying (editing) an existing task is similiar to creating a task.
From the GPS-NAV Main Flying Screen move right 6 screens to the "Task Selection"
screen. Press GO to enter the Task Edit screens. "Select Task A" will be displayed.
Press DOWN repeatedly to view other existing tasks until you find a task you wish
to modify, say Task C. Using the RIGHT key move to the turn-point(s) you wish to
change. Then use the DOWN and UP keys to find the turn-point you want to replace it
with. With the new turn-point displayed press RIGHT to move to the next turn-point,
or GO to save the edited task.
Before being returned to the Main Flying Screen after pressing GO you will be
presented with a choice of declaring and/or starting the task (see "DECLARING AND
STARTING A TASK" above for an explanation of this).



							Robert Dorning
							January 6, 2007