You really are beating a dead horse here Dean. The rule is what it is and you know what the official interpretation is. You are over interpreting what Brian Howard said. Plus he feels that way due to his IAC background. We ARE NOT saying "fly it as you want to". Rather you are saying "judges deduct what you want to without regard to the actual rules". I like our method better. It says that there are no downgrades for displacing the line during the snap as long as the two lines are exactly parallel before and after the actual snap. How much more clear does it need to be??

You actually prefer a system where Judge "A" can take two points off for any displacement, Judge "B" might take 1 point, Judge "C" might take whatever hits him as right and so on?? This is the pitfall of the "judges should develop a consistent system...." Which by the way is NOT mentioned anywhere in the snap section when talking about this issue. It is in the loops and that is being changed for exactly the reason stated above.

Here are the pertinent phrases from the F&JG

From Section 8.9.3 (bottom of page)

Throughout the snap roll, the main axis of the snap roll’s rotational
must be in the correct plane and direction of flight.

A changing rate of rotation or the nose moving more
onto the flight path (like a roll) is the most often observed change in
character.
END QUOTE


OK. So it clearly says that the snap roll must be in the "correct plane and direction of flight". Notice it does NOT say that it must be on the same line!! In fact the next line infers that if it IS on the same line it is likely more of an aileron roll as opposed to a snap roll.

The one and ONLY possible nit to pick here is that this does not specifically allow for a change in altitude on horizontal snaps, where if it happened, it would be most noticeable. This is in fact what bothers Brian the most. I know this from having discussed it with him several times. The interpretation made by Fred, Wally, and myself when we did the Summary Card was that it is reasonable to expect that if lateral displacement (on the same plane of flight, not line) is allowed then it is NOT unreasonable to also allow a displacement in altitude. Allowing a displacement along the two primary axis of control in a snap (pitch and yaw) seemed consistent.

So again, the rules AS IS are VERY clear that there is NO requirement to be on the same line, only the same plane. Further, the rules infer that being on the same line MAY be cause for a downgrade and indicate the snap was not done properly. So, the interpretation was made that allowing a vertical displacement (altitude when horizontal) was consistent. the requirement is to maintain the exact same track prior and after the snap roll. This maintains the base geometry of the figure.

I hope this puts to issue to bed for you and any others that may be having difficulty with this issue.

Bill Malvey
Chairman - IMAC Rules Committee