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ACRO E-mail Archive Thread: Competition questions


Thread: Competition questions

Message: Re: Competition questions

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From: "John Collier" <collier at>

Date: Tue, 06 May 1997 13:38:08 UTC


Having just come from a contest (Early Bird Regional at Edna, TX sponsored
by IAC #25 in Houston) where we had a 28 knot crosswind at the top of the box
I can tell you what I look for:

Looping maneuvers - the rule book says the loop must be flown in a "plane"
(a geometric plane). There was some discussion last year about whether that
plane was fixed or moved with the wind. I say it moves with the wind so your
wings better be level (perpendicular to the plane) at every point throughout
the loop. It looked like a corkscrew this weekend but if it was a round
corkscrew it got a 10. Wind correct for roundness, not ground track.

Same holds for the horizontal lines - if I can see you not parallel to the
X axis I'll downgrade you. If, because of the crosswind your groundtrack
is from one corner of the box to the opposite diagonal corner but your
heading is parallel to the X axis its not downgradeable.

All the judging criteria deal with figure geometry. The only place that
"wind correction" comes to play is in keeping the geometry of the loop
round. In all other cases, wind effects are to be ignored!

Wind affects positioning! Positioning scores are real small in the
lower categories. Your best bet for high scores is to fly the maneuver
as precisely as you can. If a crosswind causes you to be out of position,
take a break and reposition. In sportsman, a break is a 5 point penalty.
Try and cheat on a loop, lose a point of score because you aren't that
good at cheating and you just lost 10 points.

Good luck and have fun!

John Collier                         | Phone: (512) 823-6236 T/L 793-6236 
Solution Developer Operations        | FAX: (512) 823-6297
IBM Corporation                      | email: collier at
11400 Burnet Road, Austin TX 78758   |   

I will be entering my first contest (Orange, MA) in a couple of weeks.  I've
been reading the judging criteria in the Redbook, as well as reading from
various other sources, and understand most of what the judges are looking
for.  But I have a couple of questions regarding crosswind correction that I
hope this group can help to clear up.

I'm interested in (1) what the judges are supposed to look for, and (2) what
they really look for.  I won't turn down any suggestions on how to cheat...

Regarding looping maneuvers:  I understand you need wings level on
entry/exit, and that the track over the ground must be a perfect circle, as
of course all of mine are (yeah, right).  If there is a crosswind component,
this implies some combination of roll/yaw.  The question is, will the judges
downgrade if they see this, or are they just looking at the airplane's
center of mass?

Regarding horizontal lines (ie- a slow roll):  The way I read the rules,
you're downgraded for any of the following:
        - wings not level on entry/exit
        - longitudinal axis not parallel to X-axis.
        - Flight path over the ground not parallel to X-axis.

In a crosswind, the first two necessarily conflict with the third, leaving
your only option as cheating (OK with me), which in a strong wind and a weak
Decathlon is only going to get you so far.  It's not possible to avoid some
sort of a downgrade, and the real question is how to manage the flight to
minimize the downgrades.  Am I interpreting this correctly?

On an unrelated note- Anyone in the Boston area doing any critiquing this

-Steve Pennypacker


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