[Rick Kroeze]

Per Lee's suggestion. (We'll see if it stays civil.)

A copy of the last....

There are a few more things that could be posted if there is interest. I thought maybe post them individually so they can be questioned/discussed if needed.

Some of them might not be new to you but they were an eyebrow raiser to me.

Here is one:

It's not happening yet but they are getting ready, in a future season, to add 45 lines with roll elements to the entry and exit of a hammer. They are studying the repercussions because the potential for huge K factors is very high. You could have combination rolls on both the 45 lines as well as the vert up and down lines (egad!)

This has been prompted because it has been added to the FAI catalogue which we are basing our figures on.

[isabel]

Regarding the stall turn requirement mentionned by Ted (having to remove any wing-correction before the pivot and put it back aftewards) - Rick you say it sounds contradictory to remove the pitching but not the yawing and it sure does... I didn't know this rule but when I re-read the section on stall turns I see the statement: "As the aircraft nears the point where it would stop climbing, it must pivot in a plane parallel to vertical." This would imply pitch correction but not yaw correction.

Good to know... thanks for pointing out all these things. So far I thought by reading the manual I was covered, but some things, like the above, might be missed even if you are diligent in your reading...

[Rick Kroeze]

OH NO!

She's brushing up on the rules as well?

We don't stand a chance.

[scaleguy]

OK I am confused. Must the aircraft return to vertical flight in both pitch and yaw or only pitch?

[Rick Kroeze]

Only pitch

[isabel]

Hi Jim, as supporting evidence to Rick's answer (since I already typed it up while he answered) here are the rules that govern the attitude of the aircraft during the pivot part of the stall turn (quote from the rule book)

#1 As the aircraft nears the point where it would stop climbing, it
must pivot in a plane parallel to vertical.
#2 In the case of strong cross winds, the aircraft will most probably
be ‘crabbing’ to wind correct the up and downline. The pivot at
the top of the line might therefore be less or more than 180 degrees
and no downgrade should be applied to it.

I interpret it as such: From #1, the pitch has to be returned to vertical. From #2, it is understodd that the pilot is not to correct the yawing. Therfore, correct pitch but not yaw.

[isabel]

[deleted post duplicate by mistake]

[isabel]

[deleted post duplicate by mistake]

[tommy321]

Today is a day where I feel like listening to my own voice.

I'm not sure if I'd say that the line: "As the aircraft nears the point where it would stop climbing, it must pivot in a plane parallel to vertical" implies that you need to remove the pitch correction at the top of the climb. I mean, techincally, in a perfectly executed tail slide, the aircraft is also pivoting in a plane parallel to the vertical.

In the copy of the rules I'm looking at (2007-2008 AMA Competition Regulations Governing Scale Aerobatics) it says:

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.

I think that the term "vertical geometric plane" is a poor choice of words... it doesn't tell me what vertical they're referencing. Is it the earth centered vertical? or the aircraft vertical? And the phrase "wings must remain in..." doesn't mean much either. Do they mean the leading edge of the wings? the trailing edge? the chordline?

Where it gets even more confusing is where it says "(unless wind correction is required)"... which to me says that, if wind correction is required then the aircraft attitude before and after the turnaround doesn't have to be vertical. How long before and after the turnaround do we have to be "absolutely vertical".

*sigh*... Realistically, one judge will deduct marks because I broke the rule that, "There must be no rotation around the pitch or roll axis...." while judge number two will decuct marks because I broke the rule that, "the aircraft’s attitude before and after the turnaround must be absolutely vertical"

Definitely an area where the rules are as clear as mud. Just like any good engineering specification. It's still fun to pick apart though.

Tom

[Rick Kroeze]

Tom I understand some of your anguish.

However,

To me it is clear and not muddy. The plane must be vertical in pitch at the point of rotation (ideally the point of stall) It must be wind corrected going up to this point and back down from it. A "plane" (by that I mean "on a plane" stupid english language) other than dead 90 degrees up is not vertical.

Yes the aircraft will blow downrange during this rotation with no downgrades applied.

The judge 1/ judge 2 comparson is what we need to get corrected so that everyone is judging correctly and equally.

Potentially neither of those judges is getting it correct. Judge one is only correct if they are applying that criteria up to and after the turnaround, not during. Judge 2 has made up a rule. I do not see that wording. The track before and after is what is to be judged, not the attitude.

Perhaps someone could attempt at explaining it better than I? Are there those that think I have misinterpereted?