On 8/30/2011 5:14 PM, ursus wrote:
On Aug 29, 5:38 pm, Mike
wrote:
On 8/29/2011 7:26 PM, Westbender wrote:







On Aug 29, 7:09 pm, Darryl wrote:
wrote:
On Aug 29, 11:54 am, wrote:
On Aug 29, 8:48 am, Darryl wrote:

BTW the landing glider's PowerFLARM did not warn of threats as
stationary/on the ground FLARM/PowerFLARM units do not transmit
signals.
I suspect this is done for many reasons including you do not want
to
distract pilots when they are landing. Just another example of an
all
round impressive system.

Darryl

The aircraft on the ground actually do transmit a signal, but alarms
are being suppressed for landing gliders as it would distract the
pilot too much.
Urs

Under what "landing" conditions are alarms suppressed? I'd certinly
like to be alerted to an opposite base head on with another glider or
a tug.

They are suppressed if the other glider is on the ground. Don't know the
exact details of what counts as on the ground. I've had similar
comments from folks at other busy fields how well this works and Urs
explained it to me at a seminar, and I still got it backward. Sorry.
Sigh.

Darryl

Sounds like it can tell whether the target is moving or not. The ships
on the ground are probably indicating speed = zero in the flarm radio
packets. If that's the case, this device is not meant for
helicopters. )

That's an interesting question. A couple of years ago I almost had a
midair with a helicopter that was hoovering 5' off the ground at the
arrival end of the runway. Never saw him until we turned base and were
committed to landing.

If the helicopter were FLARM equipped, would he have shown up as an
alarm? Would he show up as a target on a display with a FLARM
interface, so we could have seen him before we entered the pattern (even
more important that generating an alarm at the last moment)?

--
Mike Schumann

The FLARM version for helicopters has a 'hover detection' based on
ambient noise level and accelerations / vibrations.
http://www.triadis.ch/index.php?floice
The sending unit decides on its state and broadcasts it. So the
receiving unit does *not* decide based on ground speed of the sender.
Is a FLARM equiped hoovering helicopter visible on a GPS display
connected to a FLARM unit in a glider if there is not an imminent threat
of a collision?

--
Mike Schumann