Is FLARM helpful?

At 18:03 24 November 2015, Richard wrote:
... Really James, I suspect something is very wrong with your
Flarm. ...

Interesting thought. That would mean a fault in the Flarm
algorithms, or (highly improbable) a bad but operable installation of
the Flarm firmware. And, BTW, more than one Flarm unit was used
over those years.
J.

On Tuesday, November 24, 2015 at 11:16:35 AM UTC-8, James Metcalfe wrote:
At 18:03 24 November 2015, Richard wrote:
... Really James, I suspect something is very wrong with your
Flarm. ...

Interesting thought. That would mean a fault in the Flarm
algorithms, or (highly improbable) a bad but operable installation of
the Flarm firmware. And, BTW, more than one Flarm unit was used
over those years.
J.

Since you've owned several I guess it's safe to say there's more benefit than downside.

I'd be hard pressed to say I've ever had a false alarm - I guess it depends on how you define such a thing. If you mean an alarm when there were no other gliders in the air I would definitely look at whether you need to replace the hardware or firmware. If you mean you got an alarm for a glider in the area that you didn't think was an immediate threat you might consider 'competition mode' which sets the collision parameters tighter before issuing an alarm. We all have our comfort zone, but I'd be dubious about reports of alarms where that projected flight paths of the gliders involved weren't crossing within the radius of error that the algorithm assumes. As you may recall, Flarm projects curving flight paths, so you don't need to be on a straight-line converging path to generate an alarm. In a busy thermal you'll get lots of alarms, but the flying is so dynamic that the threats can come and go with regularity. It's not so much a false alarm in that case, but a transient conflict and probably not super-helpful, but technology has its limits in the analog world.

If the OP is considering whether to equip with Flarm I'd say if you intend to fly with other gliders, get one and if the other gliders don't all have them already, organize a group purchase.

I've had lots of useful alarms. I'd wager at least one prevented me from taking the silk elevator home.

9B

One thing to point out is that James is likely referring to the European Flarm while most of us referring to Powerflarm which I understand is superior especially in the user interface side (butterfly display etc) and as such I believe better visually distinguishing between alerts and collision alarm..

Ramy

Am Dienstag, 24. November 2015 23:59:45 UTC+1 schrieb Ramy:
One thing to point out is that James is likely referring to the European Flarm while most of us referring to Powerflarm which I understand is superior especially in the user interface side (butterfly display etc) and as such I believe better visually distinguishing between alerts and collision alarm.

Ramy

I have about 1600 hours flying with the European Flarm in the French and Swiss Alps, and I have had more than one occasion where the Flarm warning solved a very hairy situation. I also have had many false alarms, but I can live with that - I'd always take a false positive over a false negative.
On the technical side, I take good care that my antenna coverage is acceptable in any direction (which requires more than one antenna on a carbon fuselage).

Bert
Ventus cM TW

It is amazing what we pay for gas, insurance, tow fees and hanger fees, and also life insurance. What is a parachute, the real life insurance not life insurance that pays your heirs. So what Flarm, another form of real life insurance, that will keep you from using your parachute incase you have too. Not to mention if you have had a collision with a sailplane or larger ship you will most likely be in bad shape. Yes I know chutes may need to be used with a collision. So to me, Flarm is just another form of real life saving insurance, that is pretty inexpensive for what it had and can do.

On the technical side, I take good care that my antenna coverage is acceptable in any direction (which requires more than one antenna on a carbon fuselage).

Bert
Ventus cM TW

Bert,
Could you tell us where you place your multiple antennas on your carbon fuselage, and the type of antennas you are using.
Thanks,
Mark

Am Mittwoch, 25. November 2015 17:34:47 UTC+1 schrieb :
On the technical side, I take good care that my antenna coverage is acceptable in any direction (which requires more than one antenna on a carbon fuselage).

Bert
Ventus cM TW

Bert,
Could you tell us where you place your multiple antennas on your carbon fuselage, and the type of antennas you are using.
Thanks,
Mark

I have an antenna splitter; one antenna is placed as a stripe antenna in the canopy to the side behind my head, and the other antenna is the standard "toothpick" placed next to a gear door.

Works well.

Bert
Ventus cM TW

At 22:59 24 November 2015, Ramy wrote:
One thing to point out is that James is likely referring to the
European
Flarm while most of us referring to Powerflarm which I
understand is
superior especially in the user interface side (butterfly display
etc) and as such
I believe better visually distinguishing between alerts and collision
alarm
Ramy

Indeed, I have not come across a Powerflarm unit, and don't know
what the differences are. But I don't feel that there is any
ambiguity in 'European' Flarm indications.
J.

Flarm just announced a new external antenna recommended for carbon and metal planes (Flarm and Powerflarm frequencies).

At 21:44 24 November 2015, Andy Blackburn wrote:
... Since you've owned several I guess it's safe to say there's
more benefit
than downside. ...

Sorry to disappoint: I haven't owned any. These were 3 different
units in 2 club-owned two-seaters, flown in the French Alps
where Flarm was mandated by all the clubs in the area.

On balance Flarm *may* indeed be beneficial. But the purpose
of my post was to point out that there *are* significant
downsides. Pilots should be aware of these and avoid indulging
in gratuitously risky practices, under the illusion that Flarm will
protect them. They should also avoid making vigorous evasive
manoeuvres in response to Flarm alone: it is imperative to see
the threat before making anything other than a gentle
manoeuvre, perhaps a small wing-waggle to aid conspicuity.
This applies not only to threats from behind / blind spots. I am
sure that vigorous manoeuvres (unexpected by the other pilot,
who could see that the situation was under control) will result in
collisions - or perhaps already have ("such a shame ... and they
both had Flarm")

Finally I should say that my initial expectation of Flarm (and
BTW I love the technology!) was that it would significantly
reduce effective lookout - I'm afraid that's just my view of
human nature. That may or may not have happened - how could
I tell? However, as soon as I flew with Flarm, I was shocked to
discover what crazy manoeuvres other pilots were making,
which I had not experienced before, and which disappeared
when I next flew without Flarm.

... I guess it depends on how you define [false alarm] ...

No, I didn't mean warnings given about empty space! I meant
collision warnings about a glider opposite me in the thermal, or
established in another, distant, thermal, or 500+ feet above or
below, etc. In other words, when no collision risk existed or
developed, regardless of how 'competitive' I felt.

J.