[NSRCA-discussion] Snap

[John Ferrell]

>From my point of view:
1. It remains the pilot's responsibility to satisfy the judges.
2. What is and is not a snap is defined by our rules.
3. All airplanes do not snap alike, see #1.
4. "Burying the Snap" by over controlling will eventually put you in a 
situation that will score poorly.

IMHO:
Those of us with a chronic problem of over controlling usually wind up 
selecting control travel limits based on what it takes to snap and spin. 
Those with the gift of fine motor control can get away with more sensitive 
controls.

John Ferrell    W8CCW
"My Competition is not my enemy"
http://DixieNC.US

----- Original Message ----- 
From: "Adam Glatt" <adam.g at sasktel.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Tuesday, July 04, 2006 2:26 AM
Subject: Re: [NSRCA-discussion] Snap


> Bob, my personal experience tells me that such a snap roll is only
> possible with little to no elevator, and decent amounts of aileron and
> rudder.  This shouldn't be a great surprise to anyone who has thought
> about the control inputs we prescribe to perform a snap.  Elevator input
> causes the plane to pitch, and pitch causes the plane to displace from
> its former path, whether the wing is stalled or not.  Rudder causes the
> plane to yaw, but yaw is much less effective at causing the plane to
> displace from its former path.  Rudder during a roll forces the tail and
> nose to rotate around the flight path.  What two things can a judge or
> pilot look for during a roll to determine if it is a standard roll,
> barrell roll, or a snap roll?  The first is the tail being at an angle
> that isn't the flight path and then not rotating around the flight
> path.  The second is the CofG staying on a rather straight path.
>
> A stalled wing (due to elevator application) produces a ton of lift.
> That lift is going to drastically move the CofG off the previous flight
> path.  This is why I advocate and practice very little elevator
> deflection during a snap.  Meeting the rules requires strong elevator
> application to begin the snap, and it also _requires_ releasing most of
> that elevator during the rotation.
>
> Of course, this is all just talk and typing.  Most important is to
> ensure your snaps don't tempt judges to whip out the big zero.  And that
> you can hit wings-level every time.  Jeez, I better keep practicing...
>
> -Adam
>
> Bob Richards wrote:
>>
>> */Nat Penton <natpenton at centurytel.net>/* wrote:
>>
>>     When the stall occurs lift only diminishes, it does not go to zero.
>>
>> Agreed, and therefore the CG of the plane can't travel a straight line.
>>
>> The "break" will cause the the wing to go through its maximum lift
>> AOA. That alone will cause the path to deviate. Once "stalled" the
>> wing is still lifting, 3D flying proves that.
>>
>> I recently flew a plane that was being video taped, and performed
>> several snap rolls coming straight towards the camera. When the
>> playback was slowed down, it was apparent the plane was NOT following
>> a straight path. The plane obviously stalled, and autorotated, but the
>> path was a spiral.
>>
>> I would like for someone to produce a video of a snap roll, flown
>> straight towards or away from the camera, where the CG stayed on a
>> straight path.
>>
>> Bob R.
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> NSRCA-discussion mailing list
>> NSRCA-discussion at lists.nsrca.org
>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>