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Old August 26th 08, 03:37 PM posted to rec.aviation.soaring
5Z
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Posts: 405
Default GPS-NAV security sealing

On Aug 26, 6:39*am, Sam Discusflyer wrote:
I want to understand the difference between the average joe (me) and a commercial
operation doing this task that was / still is in some instances conducted
by the 'official observer' on paper?


What task is that?

The FR is a "secure" instrument that is protected by a variety of
methods to prevent tampering. The GPS-NAV is the oldest of these
devices and depends on an internal battery to keep the seal intact, so
this battery must be replaced regularly (for example, during
calibration). If the battery goes bad, then an authorized facility
must reseal the unit. This way, that facility is held responsible for
any "unusual" IGC files that may come out of this FR.

If 'any Joe' could seal the FR, then prior to sealing, the electronics
inside the unit could be modified or replaced by 'Joe', and nobody
would be the wiser. The OO would see a sealed FR, trust it to
generate a true record of the flight, and a valid IGC file would be
generated.

The OO ensures that the pilot and FR were actually onboard the same
glider at the same time, and that, to his best ability, no funny
business was performed by the pilot during the flight. Since the FR
is out of the OO's control during the flight, it must be sealed by a
3rd party, and that seal must not be modifiable by just anyone at any
time.

Yes, there are a lot of holes and vulnerabilities in this system, and
all sorts of interesting ways to hack it, but so far as we know, that
has not been done yet. And the bottom line, is that those are the
rules. If you don't like them, then you can lobby to change them.
But in the meantime, this is what we have.

-Tom