[NSRCA-discussion] Suggested New Snap Roll (Brake Roll) Description

[rcmaster199 at aol.com]

Jerry Budd explained pretty well the fact that pattern planes are so lightly loaded that a?large amount of?force in pitch must exist to cause a stall. Stalls, accelerated and/or assymetric,?I don't think are what happens in a pattern snap.


?


I believe an?assymetry in lift does however. Think of the the wing as two halves (fancy that) where one sides lifts the equivalent of its whole area and the other side only a small percentage. Neither panel is stalled per se....one simply lifts less than the other. Yaw will induce the differential lift once the wing has been loaded in pitch. Assymetric lift will cause the wing to autorotate in roll axis.....we accelerate that autorotation with ailerons (duh!!). Some planes will snap with yaw command alone once pitch loading has happened. Most pattern planes will not because, as Jerry pointed out, it doesn't take a whole lot of lift to keep a pattern plane flying


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My 2c


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MattK


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-----Original Message-----

From: Martin X. Moleski, SJ <moleski at canisius.edu>

To: General pattern discussion <nsrca-discussion at lists.nsrca.org>

Sent: Fri, Oct 16, 2009 6:43 am

Subject: Re: [NSRCA-discussion] Suggested New Snap Roll (Brake Roll) Description





Keith Black wrote:?

> How about this definition:?

?

> At the start of a snap-roll, the fuselage attitude must show a?

> definite break and separation from the?

> flight path, before the rotation is started, since the model aircraft?

> is supposed to be in a stalled?

> condition throughout the maneuver ...?

?

That what Vicente (and others) are arguing is a bad?

definition for our purposes.?

?

I agree with those who want to remove all references to?

stalling from the definition of the maneuver.?

?

The model must depart (break away) from all three?

axes. Saying that the first departure must be separated?

from the other two does not make good sense to me.?

?

Demonstrating the kind of "stall" that leads to a?

spin entry is very different from the assymetric stall?

required for autorotation--at least in my own understanding?

of what accelerated stalls are like.?

?

? Marty?

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