[NSRCA-discussion] basic judging question

Wed Oct 7 17:47:14 AKDT 2009

Bob I agree there is a need for rules clarification. I checked AMA's change proposal calendar and found a cutoff date of September 30 of 'Year One'. 
http://www.modelaircraft.org/search.aspx?query=rULES+CHANGE+CYCLE
Contest Board Procedures Changes_v2final.pdf - Posted on: 11/17/2008
page 18

I became curious as to what the rule actually stated for the Figure M and found that in the maneuver description the track is clearly spelled out.

Figure M with or without Rolls: Model pulls up into one-quarter (1/4) loop to a vertical track, hesitates then performs prescribed roll, hesitates then executes a stall turn through 180 degrees, hesitates, performs prescribed roll, hesitates then executes one-half (1/2) outside loop to vertical track, hesitates, performs prescribed roll, hesitates, executes a stall turn through 180 degrees, hesitates, performs prescribed roll, hesitates then recovers with another one-quarter (1/4) loop to level flight. Direction of rolls and stall turns are pilot’s option. The length of the vertical segments is not a judging criterion. Downgrades: 
1. Model not vertical at start and finish of rolls and stall turns. 
2. Stall turns not exactly 180 degrees. 
3. Model does not execute prescribed rolls. 
4. Rolls not centered in vertical lines. 
5. Bottom of outside half loop not at same altitude as entry and exit. 
6. Loop segments not the same size and radius. 
7.Pendulum movement after stalls.

This got me curious so out came the old rulebooks.
1992-93 had a figure M with half rolls and this description. "Model pulls up into a vertical attitude, -----" the first downgrade was "Model not vertical at start and finish of rolls and stall turn"
1994-95 changed the description to.  "Model pulls up into a vertical track, -----" However the maneuver downgrade "Model not vertical at start and finish of rolls and stall turn" didn't change. This discrepancy remained through the last rulebook I have (2002-2004 and is with us today.
These apparent conflicts have been with us a while.

I think it is generally accepted that wind correction overrides general maneuver description unless stated otherwise. The mention of 180 degree rotation can probably be eliminated, superceded by the requirement to display a wind corrected vertical down line. A 180 degree rotation in a crosswind immediately brought back to a wind corrected down line would be rather ugly, however on occasion I have stalled down wind exceeding 180 degrees to prevent a 2-3 wingspan offset resulting from excessive up line wind correction.

Jim Hiller

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Bob Richards
Sent: Wednesday, October 07, 2009 10:13 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] basic judging question

Jim,

What you said is exactly how I remember the judging discussion presented at the Youth Masters re: IMAC stall turns. And I remember thinking to myself that this is not the way we did it in pattern in the '90s. Oh, well, I did not want this to turn into a pattern vs IMAC discussion again. :-\

Getting back to my original question, I think the stall turn should be wind corrected as much as possible through the stall turn itself. However, that is not how the maneuver description is written for the Figure M or the Double Stall Turn. The language used for the regular Stall Turn w/ or w/o Rolls should be duplicated, IMHO.

Bob R.

--- On Wed, 10/7/09, Woodward, Jim (US SSA) <jim.woodward at baesystems.com> wrote:

From: Woodward, Jim (US SSA) <jim.woodward at baesystems.com>
Subject: Re: [NSRCA-discussion] basic judging question
To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
Date: Wednesday, October 7, 2009, 11:02 AM
Bill – I can see where the confusion is -  as I perfectly relayed the information as taught in the SE judging seminar and confirmed in the practical judging practice held on Sundays.  The IMAC judging committee interprets the definition to mean that the attitude (fuselage) must be in the vertical plane during the rotation.  They further back this up by stating that if the plane were to be in the “wind-corrected” attitude (not perfectly vertical) during the rotation, that it would be subject to the 0.5 pt per 5 degree rule.  I’ve been in the room 3 times when Wayne M. has explained this and answered many questions from it.

Lots of discussion took place over this in the judging seminar.  Basically they are teaching that for “yaw” you can remain wind corrected, but for the pitch axis, you must be in the vertical plane.  Sorry if this seems to contradict the rule, but this is what is being taught and practiced in the South East.  

I think it looks funny, and I would prefer for the interpretation to allow “wind-correction” for any time, but I must fly what they teach as the scoring criteria SE.  On the other hand, I would love to know if this has changed as well.
Thanks,
Jim

From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Bill's Email
Sent: Wednesday, October 07, 2009 9:48 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] basic judging question

Woodward, Jim (US SSA) wrote: 

However, this dovetails into the recent IMAC & Pattern comparison threads.  In IMAC, the plane is supposed to be brought into the “vertical plane” prior to the stall-turn(pivot) taking place.  This is mostly evident if you are flying in a strong headwind where you are wind correcting the vertical line.  Just prior to the stall turn, the pilot hast to pitch the plane into the vertical plane, then yaw around the pivot, then return to the wind corrected down line.

 Not sure where you got this about IMAC, but it is incorrect. This may be the cause of your confusion (from Rule 8.5):

The wings must remain in the vertical geometric plane throughout the turnaround, and the aircraft‘s attitude before and after the turnaround must be absolutely vertical (unless wind correction is required), with no extraneous tail movement. There must be no rotation around the pitch or roll axis. If there is movement around any axis other than the yaw axis, often referred as "torquing" (Fig. 25), there is a deduction of 0.5 points per 5 degrees of axis.

At no time in IMAC is the actual attitude of the plane judged, it is ALWAYS the track of the theoretical center of mass. You are not required to alter the pitch of the plane at the point if the rotation starts if the pitch attitude in not vertical due to wind correction.

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