Moshe Braner wrote on 11/18/2020 6:52 AM:
On 11/18/2020 9:18 AM, Eric Greenwell wrote:
Moshe Braner wrote on 11/17/2020 8:12 PM:
...

How long should a unit be allowed to go beyond a year without updating? one month? One year?
10 years? You are suggesting that units with newer versions must recognize the version of
other Flarms and compensate for their reduced functionality, giving us a system that is not
operating as well as it could - which reduces our safety.

Eventually, older versions must be updated. You accept this when you install it, and it can
easily be part of your annual inspection. If you have a Flarm compatible display, it will
announce the need for the update; if you choose a non-compatible display, it is your
responsibility to remember when to update. This is no different than expecting pilots to
update their charts and check for NOTAMS.

Perhaps every Flarm unit should have a loud, annoying buzzer that activates at the end of the
first flight with outdated firmware :^)* In the meantime, Ramy's "Johnny Appleseed" approach
and reminders at contests and camps are worthwhile efforts.

AFAIK, the FLARM units transmit position reports in the blind, and there is no reason they
should stop doing that if the firmware is old.* On the receiving side, they need to interpret
the data packets that come in. As long as they can understand those packets, they should use them.

As I mentioned in my other posting, at any given moment some properly-updated FLARM units have
firmware that is up to a year older than others.* Perhaps even a larger gap, since when you
"update" it you get some version of the firmware from the FLARM web site, that is already some
months old.* Last spring we were told to use an older version 6.8.x for PowerFLARM since the
latest version 7.x had some bug.

And my guess (would love to hear from those who really know) is that the data packets
themselves have not changed in some years, even as the algorithms the unit uses to predict
which ones represent a collision hazard have improved.* Yet another reason why a unit with
older firmware should keep on operating.

Of course one should do the firmware updates, but what upsets me is the unit refusing to
operate at all if you don't.* Like I said, it should instead give some sort of semi-annoying
reminder, like an occasional sound.

My understanding is they broadcast a projected flight path for the glider in which they are
installed. The receiving Flarm calculates the collision potential based on that projected
flight path, and the one it projects for it's own glider. Flarm is not just a simple position
reporter, and it depends on both units using the same GPS data in the same way, and making
calculations the same way.

Would you excuse a pilot that does not update his database, then uses the wrong CTAF when
landing at an airport? I think the requirement for a yearly update is reasonable, the manual
states that requirement, and the unit will announce the problem on a compatible display.

A buzzer to warn the pilot might help; possibly, the Flarm could continue to broadcast it's
position and expired status, then receiving Flarms could show a big red "X" so other pilots
know they are flying near an expired Flarm. Later, they can bring their USB drives to the pilot
and encourage him to update.

I still wonder how long you think a unit should operate without updates.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1