Snao G's

[Gray E Fowler]

Technically isn't a Rev avalanche snap just a negative level snap at the 
speed at which you entered?
Or is it a SNAO?


Gray Fowler
Principal Chemical Engineer
Composites Engineering




Ed Deaver <divesplat at yahoo.com>
Sent by: discussion-request at nsrca.org
01/27/2005 05:07 PM
Please respond to discussion

 
        To:     discussion at nsrca.org
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        Subject:        Re: Snao G's


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. 
 
So, if we can slow the rev avalanche down to 70mph then the G's would only 
be -7. 
 
This seems to go along with previous arguments that speed is the key.
 
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???? 
 
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.
 
Thanx Earl.  Interesting stuff
 
ed


Earl Haury <ehaury at houston.rr.com> wrote:
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.
 
Flat and level pos snaps @ (nominally) 100mph = 13G, dropping the speed to 
70mph = 7G. (A normal pull to vertical @ 100mph = 7G.)
 
An Avalanche with a neg snap at the top measured -5G @ 50mph.
 
A Rev Avalanche with a pos snap at the bottom measured 13G @ 95mph. 
(Masters maneuver - intentionally flown fast.)
 
An Avalanche from the top (push - F05) with a neg snap and a half at the 
bottom measured -14G @ 90mph. 
 
(I normally measure around 5G on upline and downline snaps with my 
Partner.)
 
All snaps were executed with rapid / high degree elevator lead and % 
reduction of elevator during rotation.
 
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).
 
Earl

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