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<DIV><FONT face=Arial size=2>I agree with Dave in that 100mph is too fast. For a
first pass I simply tried to capture some basic data at the extremes (the
reason for using the YAK). </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I still plan to look at this in more detail,
including the forces for a variety of "non-snaps". It's surprising how much time
is involved in designing a flight plan to encompass the areas of interest,
flying the plan correctly (really need a caller), ensuring that "markers"
are flown to aid data identification, and then analyzing the data. Of
course multiples of each element must be flown to asses repeatability and
reproducibility.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>As I'm comfortable with the loads imposed during
the P/F05 flights, I'll focus on the Masters Avalanche with a variety of sizes,
speeds, snap positions, snap intensities, and "non-snaps". Still a lot of
stuff. Now if it quits raining.</FONT> <FONT face=Arial size=2>Oh, and I
can remember how to do a non-snap.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Earl</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>----- Original Message ----- </DIV>
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<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=DaveL322@comcast.net href="mailto:DaveL322@comcast.net">David
Lockhart</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, January 27, 2005 10:13
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Snao G's</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Ed,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>A couple answers I can think of (and
I'm sure there are more possibilities) -</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- Flight speed - for F3A at 150 meters, 100
mph is a pretty fast pace. 70-75 mph is on the the slow side. I
know I tend to fly at low 80s with my Vivats.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- snap wasn't/isn't really a snap.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- I do know of several planes coming apart on
either the 1.5 snap / 4/8 or the 1.25 snap / 1.25 opp roll in
F3A.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- Most of the F3A flying I saw did have a reduced
entry speed to the 1.5 snap.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- Average weight of F3A plane is lighter (but
same spar strength) resulting in less load on the tube/spar structure?
(compared to average weight of planes damaged to date on the Rev
Avalanche).</FONT></DIV><FONT face=Arial size=2>
<DIV><BR>Regards,</DIV>
<DIV> </DIV>
<DIV>Dave</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=divesplat@yahoo.com href="mailto:divesplat@yahoo.com">Ed Deaver</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, January 27, 2005 6:07
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Snao G's</DIV>
<DIV><BR></DIV>
<DIV>So, if I am interpreting these numbers(realize only one day and flight)
correctly. Beings the straight and level pos snap at 100mph(not
unusual speed) was -13G's and the Rev avalance at approximately 95mph was
-13G's, then the forces are about the same. </DIV>
<DIV> </DIV>
<DIV>So, if we can slow the rev avalanche down to 70mph then the G's would
only be -7. </DIV>
<DIV> </DIV>
<DIV>This seems to go along with previous arguments that speed is the
key.</DIV>
<DIV> </DIV>
<DIV>My question is, if the G's on flat and level snaps are approximately
the same, with approx equal speeds, as the rev snap, then why hasn't FAI
pilots been breaking planes with the 1.5snapopp 4/8???? </DIV>
<DIV> </DIV>
<DIV>Before anyone says it, I have seen many of these 1.5 snaps flown with
some speed, so they weren't just puttputt into it.</DIV>
<DIV> </DIV>
<DIV>Thanx Earl. Interesting stuff</DIV>
<DIV> </DIV>
<DIV>ed</DIV>
<DIV><BR><BR><B><I>Earl Haury <ehaury@houston.rr.com></I></B>
wrote:</DIV>
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<DIV><FONT face=Arial size=2>FWIW, I took a quick look at some snap G's
yesterday. Equipment was a Quique YAK (140 size) fitted with an Eagle Tree
Systems datalogger with G sensor. I only gathered data from one flight -
so take that into consideration.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Flat and level pos snaps @ (nominally)
100mph = 13G, dropping the speed to 70mph = 7G. (A normal pull to vertical
@ 100mph = 7G.)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>An Avalanche with a neg snap at the top
measured -5G @ 50mph.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>A Rev Avalanche with a pos snap at the bottom
measured 13G @ 95mph. (Masters maneuver - intentionally flown
fast.)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>An Avalanche from the top (push - F05) with a
neg snap and a half at the bottom measured -14G @ 90mph. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>(I normally measure around 5G on upline and
downline snaps with my Partner.)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>All snaps were executed with rapid / high
degree elevator lead and % reduction of elevator during
rotation.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I may look at this further as the mood
strikes. As expected, controlling speed into snaps is easier on
your airplane. None of the observed loads (in my opinion) should damage a
well constructed aerobatic model (wouldn't want to ride in it
though).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>Earl</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>