GPS-NAV
How
do I edit or remove Mark Points?
Why
do multiple flights show up as one flight log?
I have downloaded a Turnpoint Database from
the Internet, how do I load it into my Flight Recorder?
I sent in my GPS-NAV for Calibration and
received a Certification Sheet, why?
Does the GPS-NAV contain an "Event
Marker"?
Why
am I finding task declarations in files which were not
declared.....?
I just flew a record flight but my GPS-NAV
is out of calibration, what should I do?
Does my GPS-NAV contain a 12 channel
receiver?
Why is the GPS altitude different than the
recorder altitude?
How do I install my GPS-NAV and L-NAV in a
two place ship?
Will
my GPS-NAV continue to function correctly in the Year
2000?
I have found that with GPS
version 5.1 I cannot delete Markpoints in the Markpoint
menu.
Is there any way to make
Markpoints into turnpoints through an easy process, or
does one have to write down the Lat/Lon of the Markpoint
and enter as a turnpoint through the PC?
Recent GPS-NAV Firmware
releases removed the capability of deleting Navigation
Points. This includes Markpoints captured with the
GPS-NAV LCD screen during flight. This change was made to
prevent inadvertent Navigation point deletion under the
high stress conditions of a competition.
Markpoints can be edited
from the GPS-NAV screen. Editing includes naming
the point, giving it an identifying number, changing the
captured altitude to a known elevation, and giving the
point Turnpoint (T) and/or Landable (L) attributes.
Turnpoints show up in the Task editing screens, while
landable points show up in the Navpoint selection screen
ordered by distance from the current location.
If you edit the points
from the GPS-NAV screen, they will show up in the
appropriate form while viewing the flight (provided you
choose to view the flight with Navpoints from the flight
log.). An extra step is required to bring Markpoints into
the PC database. Here are the required steps:
1. Make sure the PC
Navigation Point Database is for the appropriate Site.
2. Display the Flight Log
that contains the Markpoints of interest.
3. From 4 - PC Databases /
6 - Special Functions, select the IMPORT button at the
top of the screen.
4. Choose the Import
source labeled "Most recently displayed flight
log", and press enter.
5. Select "IMPORT
NEARBY NAVIGATION POINTS FROM THIS FILE"
This will add the
Markpoints to the PC Database for the selected site. Once
the Markpoints are in the PC database they can be edited
in the normal way. This means you do not have to edit
point on the GPS-NAV screen.
Why do multiple flights
show up as one flight log?
A flight recorder cannot
reliably distinguish a "real" flight from the
short auto tow from the glider trailer to the takeoff
point. It also cannot distinguish between a real soaring
flight and an aero retrieve after a landing. Also,
consider the case where the pilot inadvertently turns the
flight recorder off and back on again during a flight.
How can a device of limited intelligence understand all
possible variations in flight logs and reliably assign
the appropriate declaration?
Therefore, one of the
early (1992!) decisions we made concerning flight logs in
the GPS-NAV was to have only one declaration in the
flight recorder. We also decided to record substantially
all the motion detected within a "day" as one
flight log. To assure that no flight logs would be
inadvertently written over by the PC, we assigned unique
file names to each log.
The PC program and a human
observer are much more adept at flight log interpretation
than the flight recorder. Our system guarantees that
there will be a declaration for the simple case of one
declaration, one flight.
How does the GPS-NAV know
when to create a new flight log? Versions 5 and above
look for gaps of more than 8 hours between logged points.
Logged
points separated by less than 8 hours are grouped
together as one flight. Logged points separated by more
than 8 hours are listed as separate flights. If you
transfer a flight log and then do another flight with
less than an 8 hour time separation, the first flight log
will have the file name YM DCsss1.cai, and the second
flight log will have the file name YMDCsss2.cai. The
second flight log will contain all the points from the
first flight log. It is left up to the observer to
evaluate this data.
It is possible to make two
separate declared flights on one day, but it is not
convenient. If one pilot wishes to make two flight with
different declarations, the first flight must be
transferred to a PC before the second declaration is
made. If two different pilots each wish to use one
GPS-NAV to make a declared flight on one day, the first
flight must be transferred and the new pilot's name must
be entered in the GPS-NAV before the second flight is
declared. The act of transmitting new pilot or navigation
point data to the GPS-NAV also deletes previously
recorded logs and declarations.
The primary goal of our
flight recorder was to reliably capture both declarations
and flight logs. Convenience in somewhat rare situation
where two declared flights were to be made in one day was
a secondary goal.
Laptop computers can be
used on the glider field to transfer flight logs.
Adequate laptop computers can now be purchased for less
than $1200 new and $500 used.
Cambridge will soon have
Pocket-NAV graphic display software that will transfer
flight logs from the GPS-NAV to a compact flash card.
Logs can then be transferred to a PC at the pilot's
convenience.
I hope I have explained
clearly the design rationale for the GPS-NAV, and the
reasons why it evidently does not meet your expectations.
Thanks for taking the time to express your concerns to us
at Cambridge. Customer feedback is a vital part of the
thought process we use in upgrading our products and in
the design of new products.
Dave Ellis
I
have downloaded a Turnpoint Database from the Internet,
how do I load it into my Flight Recorder?
Download the list of
navpoints in .CAI file format.
Copy the file to your C:\cai\data\ directory and give it
the extension .dat, in other words, if you have a
file titled uvalde.txt then you would copy the file to
your C:\cai\data\ folder and call it uvalde.dat
Once you have accomplished
this then start the GPS-NAV Software (go to C:\cai and
type GPS). You must have your GPS-NAV connected to your
computer via the serial data port.
Go to PC Databases.
Then go to Soaring Sites.
Then ADD a soaring site.
Give it a name and enter through all the other fields
until you see POST at the top of the screen. (Post just
means 'save changes').
Now you have a new soaring site with no navpoints.
Now choose Exit.
Now go to Special Functions.
Now choose Import.
Now choose Navpoint Export File.
Now type in the full path and filename,
C:\cai\data\uvalde.dat and press Enter.
Select Import All Navpoints.
Now it should tell you how many navpoints there are.
Select Import XXX navpoints.
It should tell you XXX navpoints were imported. Press any
key.
You should now have the turnpoint database loaded in your
Flight Recorder.
Last
September, I sent in my GPS-NAV barograph for
calibration. I received a certification instead. I'm
planning on documenting some badge flights but the rules
state that calibration is required. Was this because the
certification showed that the accuracy was already
sufficient and calibrating would not improve anything?
The sheet that you poses,
thought it is titled "Certification", is indeed
the "Calibration" sheet. You are right in that
the accuracy of the instrument was sufficient. The
confusion lies in the wording of the rules. When you sent
your instrument in for service we did indeed certify that
the original calibration was still within specifications.
If we would have found that the calibration was not
within specifications, we would have physically adjusted
the altimeter to bring it within the specification. That
being the case, we would have sent you the same document
stating that the calibration was within specifications.
This is not the first time
this question has come up, so we have since re-titled the
sheet the "Calibration" sheet. We are not doing
anything different to the instrument, but by re-naming
the sheet we are making the rule makers happy.
Does the GPS-NAV contain an
"Event Marker"?
At the 1999 Worlds in
Bayreuth the IGC will require all competitor's Flight
Recorders to have Event Marker capability.
We have released version
5.4 for the GPS-NAV. This release has the Pilot
Event marker that works as follows:
If you press the ON key
you will hear a single, short "beep" from the
GPS-NAV. The "fix" recorded at that instant
will have a flag bit set. This will be interpreted in
both the .CAI file and the .IGC file as a Pilot Event.
The ON key is hard-wired
directly to the GPS-NAV Flight Recorder. This means that
a GPS-NAV with no LCD screen can still have a remote
pushbutton for the Pilot Event. Click here to view how to wire the remote
event marker switch.
As always, Cambridge Aero
Engineers will be present at the competition to provide
support and facilitate upgrades to Cambridge Flight
Recorders.
Why am I finding task
declarations in files which were not declared and how can
I edit the file to remove the declaration?
A flight declaration can
be made from the GPS-NAV display or from the PC software.
The usual method is from the GPS-NAV display. A PC task
with code "A" will be sent to the GPS-NAV
during database transfer. This permits a declared flight
to be made without need for a GPS-NAV navigation display.
Our primary goal in
defining how declarations work in the GPS-NAV was to
preserve a valid declaration with its associated secure
flight log. The GPS-NAV keeps only one flight
declaration; it is transferred with every flight log. The
declaration contains its own date and time. This can be
used to determine if the declaration applies to the
flight in question.
The only way to remove a
declaration from the GPS-NAV is to transfer a new
database into it.
A declared task stays in
the GPS-NAV until another task is declared. Any flight
that is transferred from the GPS-NAV to a PC will contain
the Declaration.
If you do not want to see
an inappropriate declaration with each flight, view the
flight with the database from the PC rather than the
flight log. The PREFERENCES menu lets you highlight this
database source by default.
If you do not have the
appropriate database in your PC, you can import it from
the flight log itself.
I just flew a record flight and
my GPS-NAV has not been calibrated since I purchased it
two years ago. What can I do?
You may send you
instrument to the factory and we will do a certification
of the altimeter and motor run. What this means is that
we will check it against our calibration station and
record the variances in altitude. You may still claim
your record flight, but you must include the
certification sheet. The variances will be factored into
your claimed altitude.
The cost of this
certification is $60.00 (U.S.) and at the same time we
will calibrate your instrument. this calibration will be
good for twelve months.
I have heard that Garmin has
introduced a 12 channel GPS receiver. Does my instrument
contain one? If not, can I have one installed into my
GPS-NAV?
We changed to the 12
channel receiver with serial number 499. There is a
significant improvement in performance with the 12
channel receiver. Satellite acquisition is faster and the
addition of up to four more satellites reduces the
occurrence of signal drop-out.
If you would like to have
your instrument upgraded, you may return it to a service
dealer or the factory. For factory upgrades the charge is
$350.00 (U.S.).
Why is the GPS altitude
different than the recorder altitude?
Our GPS-NAV measures
altitude with an internal pressure transducer which
should be accurate to within 50-100 ft. This is viewed in
the pressure altitude screen. The GPS altitude screen
provides altitude information derived from the GPS
receiver which can be off by as much as a couple of
hundred feet. This is the reason for the transducer-it's
simply more accurate and reliable.
How do I install my GPS-NAV and
L-NAV in a two place ship?
Click here to view written instructions.
Click here
to view wiring diagram.
Will my GPS-NAV continue to
function correctly in the year 2000?
Below are listed the
products with comments as related to the Y2K issue.
M-NAV: Non issue.
S-NAV: Non issue.
L-NAV: Non issue.
CAV: Non issue.
GPS-NAV PC Software: The Y2K bug has been
corrected in Version 5.88.
GPS-NAV: The
release of V5.4 for the Flight Recorder has a fix for a
leap year bug that was discovered during our Y2K
investigation. During our investigation no Y2K
problems were found. However, we did find that if a
flight log is being recorded at midnight UTC, December 31
at the beginning or end of a leap year, the flight log is
divided into two parts.
The GPS receivers
contained within the Models 10, 20, and 25 is supplied by
Garmin International. Please read the Garmin Y2K Statement on their website.
During the end of
week event (EOW) in August some GPS-NAV Model 10s
experienced problems with satellite acquisition due to
the old eight channel receivers. Garmin states that they
no longer support the old eight channel receiver
(GPS-10). After the event, we were able to write some
code that enabled the GPS-10 receivers to "wake
up". We were not able to anticipate (simulate) the
EOW event as we have no control over the data that is
received by the GPS-NAV from the satellites. We do not
know what will happen at the rollover to the year 2000
with regard to the GPS-10 receivers. Garmin states that
there should not be a problem. If there is, Cambridge
Aero will make every attempt to correct the problem.
Worst case is that the Model 10 will need an upgrade to
the current GPS-25 receiver. This hardware upgrade will
not be considered a warranty issue.
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