[NSRCA-discussion] Snap entry in FAI

[rcmaster199 at aol.com]

A "Flick" and a "Snap" roll are the same roll in full scale aerobatics 
parlance and reference material.

Do these mean the same thing in model aerobatics? In my view, they do

The latest FAI regs allow actuation of the three main axes 
simultaneously...that is, the regs don't specifically differentiate 
"Pitch Break" from other deviations. I don't think they specifically 
require that the model must rotate about it's flight path either, I 
don't believe (.....plane must rotate in a conical fashion about the 
fight axis....). The model would probably present the best if that's 
done, so pilots may want to consider that when executing the maneuver.

In my take, a rapid Pitch is desired to preload the wing. Contrary to 
popular belief, both panels dot not have to stall for a snap to occur. 
Quite the opposite. Upon rudder deflection, the port panel will 
practically stall (lift much much less than the other panel) but the 
starboard panel must be lifting to create the autorotation. If both 
panels stall, the model will fall out of the sky for a distance and a 
snap would not occur at the correct moment in time

MattK

-----Original Message-----
From: Woodward, Jim (US SSA) <jim.woodward at baesystems.com>
To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
Sent: Mon, 16 Jun 2008 8:47 am
Subject: Re: [NSRCA-discussion] Snap entry in FAI

Guys,

I thought the FAI changes explicitly allowed flick rolls?  The rule
reads, "... fuselage attitude must show a definite break and separation
from the flight path."

It does not say, "MUST SHOW PITCH BREAK."   Please DO NOT ERROUNIOUSLY
APPLY A PASS/FAIL MAJOR DEDUCTION initial assessment to the snap roll.
Watch the whole maneuver then render your score.

A break and separation from the flight path simply means that the nose
and tail of the plane must rotate in a conical fashion about the fight
axis.  Yaw, roll, and pitch can all break at the same moment if that is
how the pilot does it.

Hey :) some really handsome smart guy wrote some stuff at this link
below about snap rolls to help clarify how they are done in IMAC.

http://www.mini-iac.com/DesktopDefault.aspx?tabid=77

thanks,
Jim