Are positive snaps in the Advanced pattern Avalanche zero's?

[Dean Pappas]

Speed is the answer: if you have enough speed at the top of the loop (and loop tightly enough) then the plane is "G" loaded sufficiently that the transition to stall happens quickly and cleanly. Back in the early Turnaround two-stroke 60 days, I would change my avalanche from positive to negative if I was flying big, the day was hot, or the needle was a click too fat. If the 'mo was there, though, the positive snap would maintain heading better. 
Regards,
    Dean P.

-----Original Message-----
From: Troy Newman [mailto:troy_newman at msn.com]
Sent: Tuesday, August 12, 2003 2:43 PM
To: discussion at nsrca.org
Subject: Re: Are positive snaps in the Advanced pattern Avalanche zero's?


no...
 
Positive or negative snaps are allowed in an Avalanche...the direction or the orientation of the snap is not defined.
 
Diving or climbing has nothing to do with the stall....
 
If this diving into a stall was the case how could there be snaps on a downline....? F3A has many of them
 
To snap a model you have to stall the wing...which means it gets a pitch Break...this break can be up or down....what happens is the model pitches quick enough that the wing stalls...
 
It has nothing to do with speed of the model or orientation of the model...you can still stall the model and complete a snap. At any speed, any throttle setting, any orientation you can stall a model...sometimes it might take more elevator than other times. Example the higher the energy coming into it...the harder it is to get the stall clean...and you need lots more elevator throw...But the model doesn't care if its upside down snapping inside or right side up snapping outside........it can be accomplished if the model stalls. 
 
I sometimes will snap in the positive direction on an avalanche as it helps me personally maintain the loop radius...depends on the model too..some models will snap better in an avalanche doing a pos or a neg vs the other way.
 
TN

----- Original Message ----- 
From: mike  <mailto:mups1953 at yahoo.com> mueller 
To: discussion at nsrca.org 
Sent: Tuesday, August 12, 2003 2:14 PM
Subject: Are positive snaps in the Advanced pattern Avalanche zero's?

I was on RCU and I happened upon this post by Mark Novak from Belgium. It's in reference to the 0's that CPLR received on his snap at the WC's.
  
The snap roll has been discussed at length this season. 	(post  <http://www.rcuniverse.com/showthread.php?postid=1278081#post1278081> # 45)	

5B.4.3.5. SNAP-ROLLS 
A snap-roll is a rapid autorotative roll where the model aircraft is in a stalled attitude. 
Snap-rolls have the same judging criteria as axial rolls as far as start and stop of the rotation and constant flight 
path through the manoeuvre. 
Since the model aircraft is in a stalled condition throughout the manoeuvre, the attitude and flight path must 
show a definite break before the rotation is started. If the stall does not occur and the model aircraft barrel-rolls 
around, the manoeuvre is zeroed. 
Snap-rolls can be flown both positive and negative. The same criteria apply. If the model aircraft returns to an 
unstalled condition during the snap, it is severely downgraded. 


The type of critical judging is not taking place in national or regional contests...probably a disservice to the pilots rather than a good to have gimme'. The extraordinarly rapid roll accelerated with rudder (hmm, reminiscent of IMAC and TOC flying) is no longer going to constitute a "stalled condition" and it never should have. Full size pilots have battled about high scores going to what really amounted to dirty rolls and would have more properly deserved to be zeroed. Without the stalled condition, the perfect exit upon heading amounts to squat. 

I guess it is better now to sacrifice a little in heading and exit altitude than to speed through the dirty roll looking pretty with a big goose egg to show for it. 

It seems correct. if Christophe even took a 3 or 4 on the snap..4/8 he would have a significant margin of lead at this time.

Mark



Now this has got me thinking about the Avalanche in the Advanced pattern.If one did a positive snap at the top than the score would have to be a 0. How could you stall a plane while diving into a snap? If this is correct than the only way to do this maneuver is with a negative snap. The rule book states that the snap is an option. I know that the snap issue has been beaten to death but I think this merits attention. Mike



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