[NSRCA-discussion] Mid-Air discussion

[J N Hiller]

Yes Tony. It makes a lot more sense than designating someone to anticipate a
potential midair far enough in advance to call for an official flight
interrupt for the pilots to initiate avoidance maneuvers. The impact would
likely occur before the horn sounded. The flight interruption if sounded
unnecessarily would likely have a negative effect on the pilot’s flight
scores. Attached is a PDF file printed from a CAD layout showing the flight
lines angled 5 degrees from two flight stations 30 m apart. Those of us that
regularly fly 10 degrees off line generally initiate the error exiting a
turnaround which even if parallel to the other line of flight would have
sufficient separation. The close flight I had this season was with a master’
s pilot (I fly advanced). Prior to the close call in the center we went up
on a turnaround together with little more than the flight line separation
between us. Although it looked like impending doom as I remember one was a
stall turn and the other a half square resulting in no exit conflict, which
I was aware of at the time and totally comfortable with. I surely would not
have wanted to hear the abort horn.
Got to go fly now.
Jim Hiller

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Mark Atwood
Sent: Wednesday, September 26, 2007 7:56 AM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] Mid-Air discussion

Offsetting the flight lines by 10deg where it can be done has a HUGE impact.
That reduces the mid-air “zone” by about 80%.   Spotters really aren’t all
that practical.  The few times that you can really “see” a mid-air coming is
when both planes are tracking in the same direction in similar maneuvers and
you see it coming...those mid-airs are seldom the catastrophic ones that
total the aircraft.  It’s the head on collisions that  no one sees that put
both planes in the ground.  There’s maybe .5 seconds to see it coming IF you
were just looking for that, and there’s no way to react to that.

IMAC events call avoidance more easily because A) the planes are flying MUCH
slower, B) they’re MUCH bigger so it’s easier to gauge their depth and C)
they’re less often in the exact same plane of reference.

I really think the offset...where it can be done, would provide the most
benefit.  Very easy to accomplish at most fields.

-M


On 9/26/07 10:43 AM, "Tony" <tony at radiosouthrc.com> wrote:
Or we can go to less-rounds per event and fly one at a time.  They do that
in Europe for exactly that reason.



Tony Stillman, President
Radio South, Inc.
139 Altama Connector, Box 322
Brunswick, GA  31525
1-800-962-7802
tony at radiosouthrc.com
  _____

From: nsrca-discussion-bounces at lists.nsrca.org [
mailto:nsrca-discussion-bounces at lists.nsrca.org]
<mailto:nsrca-discussion-bounces at lists.nsrca.org%5D>  On Behalf Of Jay
Marshall
Sent: Tuesday, September 25, 2007 6:52 PM
To: 'NSRCA Mailing List'
Subject: Re: [NSRCA-discussion] Mid-Air discussion

I’ll say again - the easiest way to prevent mid-air collisions is to fly in
different (geometric) planes. If the flight planes are intersected 10 deg.
to each other then the probability of collision is greatly reduced.


Jay Marshall

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org [
mailto:nsrca-discussion-bounces at lists.nsrca.org]
<mailto:nsrca-discussion-bounces at lists.nsrca.org%5D>  On Behalf Of Keith
Black
Sent: Tuesday, September 25, 2007 5:48 PM
To: NSRCA Mailing List
Subject: [NSRCA-discussion] Mid-Air discussion


Following my mid-air at the N. Dallas contest this weekend there's been an
RCU thread started on the subject. >From this discussion an interesting idea
has evolved. For those who would like to read the thread here's the link:
http://www.rcuniverse.com/forum/m_6409493/anchors_6413018/mpage_1/key_/ancho
r/tm.htm#6413018



If you'd just like to hear the idea I'll paste my RCU posting below:



This is my third mid-air in four seasons. My first may have been avoided,
but the last two were a complete shock to both me and my caller. In fact, in
mid-air #2 my caller said "you're good" (meaning we were not going to hit).
The other pilot's caller walked up to me and apologized saying that he told
the other pilot that he was in the clear. Therefore, I don't know how
effective a third "spotter" sitting between the lines could be.
That being said, two recent events have given me an idea of how we might be
able to greatly improve this problem. The first light bulb was Vicente's
suggestion of the spotter that warns the pilots. The second event was my
walk out to pick up the fragments of my beloved Brio. As I was walking back
I stood for a bit to observe the planes looking down the flight path. It was
amazing how clearly you can see each plane as it moves in and out from the
flight line.
So here's the idea: What if we sat a spotter at the corner of the box to
watch plane separation in the distance out dimension and then had the other
spotter sitting between the judges (or even back under the cover) watching
in the right to left dimension. These two spotters could use radios with
headsets and continually talk to each other. There are many times that
planes appear to be close to a mid-air from the flight line viewpoint,
however, the number of times that both spotters would be alarmed should be
fairly minimal. When this occurs the spotter could sound an alarm (this
deserves discussion as to the details) and each pilot could peel off of
their course. If one pilot froze the collision may still be avoided by just
one pilot taking action. Sure, this could cause a mid-air, but viewing from
two dimensions should help in alerting only when an impact is probable.
Some have stated that they've seen very few mid-airs, but my experience in
D6 and NATS is that at least 70% (if not more) of the contests I've attended
have had mid-airs. I'm not going to run away crying and quit the hobby due
to this mid-air, but reducing such losses would be a benefit to us all!
Keith Black
  _____

_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20070926/08786b26/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Angl Flt Ln.pdf
Type: application/pdf
Size: 2924 bytes
Desc: not available
Url : http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20070926/08786b26/attachment-0001.pdf