[NSRCA-discussion] Two killed by model airplane

Sun May 21 17:59:16 AKDT 2006

Assuming it was a radio reception problem. Maybe the
battery plug came out of the receiver, or a an
extension came unplugged, or the switch failed. There
are lots of failure points beyond the rf connection.

--- brett terry <brett.terry at gmail.com> wrote:

> Once they perfect the DSS systems we may see most of
> these problems go
> away.  It is my understanding that most of the
> interference we experience is
> significantly lower in frequency than the DSS
> channels (2.4 GHz).
> 
> On 5/21/06, Ed Alt <ed_alt at hotmail.com> wrote:
> >
> >  Bob:
> > Ther are kill switches that can be set to work
> with a pre-set failsafe
> > output.  I think the problem with what you wuold
> like to see is that without
> > some failsafe response from the receiver, it's
> hard to predict what you will
> > get during interference. I don't think it's
> unsolvable though.  If you used
> > a spare channel for the kill switch, even a PPM
> receiver solution could
> > work.  A partially reliable solution would require
> either a PCM or PPM
> > receiver to reliably hold one position and
> anything outside a narrow
> > tolerance range would trigger the cutoff.  That's
> easy to do.
> >
> > Here's a better solution, but it requires some
> cooperation from the radio
> > manufacturers.  What is really needed is a
> so-called "keep-alive" signal
> > sequence from the transmitter.  Veryone should
> standardize on the same,
> > exact thing in a case like this.  Keep-alives are
> used all the time in
> > computing gear, to help "harden" the solution for
> failure detection/recovery
> > etc.  It's as old as dirt, used in Telecom, other
> mission critical stuff for
> > medical, military etc.  The idea in its simplest
> form is that a cyclic
> > signal with known attributes is sent to the
> "target" (the kill switch for
> > us).  If the target doesn't get what it expects
> within it's timeout
> > interval, it can initiate whatever action is
> deemed necessary.
> >
> > This can be far superior than just camping on a
> simple steady pulse
> > position value, since you can make the probability
> of continuously receiving
> > a "good" sequence from a bad RF link
> astronomically high.  In other words,
> > you can set the level of signal link deterioration
> before acting on it to
> > something very fleeting or make it take longer to
> detect if you want a
> > higher certainty that it is time to act on a bad
> link.  So you could make
> > the "stay running" sequence a known series of
> varying pulse widths, even
> > using varying timing between the varying widths. 
> None of this is especially
> > difficult to do, nor should it be very expensive. 
> On top of this, you could
> > een couple the engine kill response to a loud
> piezo speaker and chirp out a
> > warning - "Incoming".  Make it an industry
> standard chirp sequence and it
> > wuold be an unmistakable sign that a model was no
> longer under control of a
> > good link.  Then, any 3rd party devices that want
> to work with this have to
> > get on board and be redesigned to recognize the
> standard LOS (loss of
> > signal) protocol.
> >
> > Ed
> >
> >
> > ----- Original Message -----
> > *From:* Bob Pastorello <rcaerobob at cox.net>
> > *To:* NSRCA Mailing List
> <nsrca-discussion at lists.nsrca.org>
> > *Sent:* Sunday, May 21, 2006 1:48 PM
> > *Subject:* Re: [NSRCA-discussion] Two killed by
> model airplane
> >
> > I have oft wondered if an "ignition CUT off" that
> sensed loss of RX
> > decoder outputs that would KILL the motor wouldn't
> help.  It would at least
> > mitigate the energy of the impact.  Never heard of
> one out there that works
> > exactly like I'm describing, and it would probably
> only be effective for
> > gassers at this stage, but it may REDUCE the
> degree of injury.
> >
> > I fear full DUAL RF_Link redundancy in our
> future....
> >
> > Bob Pastorello
> > www.rcaerobats.net
> > rcaerobob at cox.net
> >
> > ----- Original Message -----
> > *From:* brett terry <brett.terry at gmail.com>
> > *To:* NSRCA Mailing List
> <nsrca-discussion at lists.nsrca.org>
> > *Sent:* Sunday, May 21, 2006 12:39 PM
> > *Subject:* Re: [NSRCA-discussion] Two killed by
> model airplane
> >
> > Lest we forget, or become careless because of the
> relative size of our
> > planes to the 50% scale Pitts that killed the
> people in Hungary, remember a
> > young girl was killed in China a few weeks ago by
> a 21-size trainer.
> >
> > Like you said, it is only a matter of time.  We
> must always be wary of the
> > danger, and make sure everybody at our fields also
> follow safe practices.
> >
> >
> > On 5/21/06, Ed Miller <edbon85 at charter.net> wrote:
> > >
> > >  Having just spent a week at the Joe Nall event
> it is clear to me it is
> > > only a matter of time before a similar tragedy
> happens here in the US.
> > > Ed M.
> > >
> > >  ----- Original Message -----
> > > *From:* mike mueller <mups1953 at yahoo.com>
> > > *To:* NSRCA Mailing List
> <nsrca-discussion at lists.nsrca.org>
> > > *Sent:* Sunday, May 14, 2006 11:10 PM
> > > *Subject:* Re: [NSRCA-discussion] Two killed by
> model airplane
> > >
> > >  Sad news,it should remind us that were only a
> serious accident away
> > > from potentially being grounded. We can all say
> that we fly safe and yada
> > > yada yada but if the radio fails it could be a
> disaster. Man I hope this
> > > doesn't happen again. I once witnessed a young
> girl getting hit by a plane
> > > in the 70's and it still haunts me.
> > > --Mike
> > > *Doug Cronkhite <seefo at san.rr.com>* wrote:
> > >
> > >  Yep.. 4 others were injured. Looks like it was
> a 3W Pitts Model 12 that
> > > crashed. The pilot was arrested by police at the
> scene..
> > >
> > > -Doug
> > >
> > >
> > >
> > >  ------------------------------
> > >  *From:*
> nsrca-discussion-bounces at lists.nsrca.org [mailto:
> > > nsrca-discussion-bounces at lists.nsrca.org] *On
> Behalf Of *Ed White
> > > *Sent:* Sunday, May 14, 2006 7:50 PM
> > > *To:* NSRCA Mailing List
> > > *Subject:* [NSRCA-discussion] Two killed by
> model airplane
> > >
> > > Yikes.
> > >
> > >
>
http://english.mti.hu/default.asp?menu=1&theme=2&cat=25&newsid=219887
> > >
> > >
> > >
> > > _______________________________________________
> > > NSRCA-discussion mailing list
> > > NSRCA-discussion at lists.nsrca.org
> > >
>
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
> > >
> > >
> > >   ------------------------------
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> 
=== message truncated ===>
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Bob Kane
getterflash at yahoo.com

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