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ACRO E-mail Archive Thread: Proposed Rule Changes - An open letter to Howa ...


Thread: Proposed Rule Changes - An open letter to Howa ...

Message: Proposed Rule Changes - An open letter to Howard Stock

Follow-Up To: ACRO Email list (for List Members only)

From: AcroDrew at

Date: Sun, 13 Oct 1996 13:20:50 UTC


  This is an open letter to Rules Committee chair and IAC Vice President Howard

The following rules changes are proposed for consideration.


Change the wording of this single paragraph section to include,"Results of
the Unlimited 4-minute freestyle will not be included in this determination."
 This sentence should be placed between the first and second sentences.

The purpose of this change is becuase the grading criteria for the 4-minute
freestyle are different than the criteria for all other contest flights.  In
addition, according to rule 5.6.6, the Contest Jury decides who may
participate in the event.  In at least one instance in a major contest (U.S.
Nationals) the team trophy was awarded to a Chapter only by including both
the normal constest flight percentage and the 4-minute freestyle flight
percentage from a single pilot (as separate percentages) along with the
normal contest flight percentage of another pilot.  In other words, only the
performance of two pilots was considered becuase one's performance was
considered twice (normal sequences + 4-minute freestyle).


Change rule 5.1.2. to move the unknown programs ahead of the freestyle:
"Category flight programs will be flown in the following order: Known, Unknown
, Free, and 4-Minute Free."

The purpose of this proposed change is to allow truncated contests to test
more than skills of practiced flights only.  By adding moving the unknown
ahead of the freestyle, there is more likelihood that a contest that is
shortened by weather problems will have included the Unknown programs which
test skills not demonstrated in practiced flights.


Add requriements for additional figures and difficulty to the Intermediate
Freestyle as follows:

Change difficulty in rule 6.2 for the Intermediate category to 200K.
Change versatility specified in Chapter VI of the Intermediate category to
include a requirement for a vertical upward roll of no less than one-quarter
turn and a requirement for at least one combination roll of any type.

The purpose of this proposed change is to make the Intermediate freestyle
program a better venue for learning the skills necessary for flight in
Advanced or Intermeidate categories and to make the Intermediate category
flights more difficult than Sportsman without an excessive difference between
the two.


Delete section 8.3.3., 8.3.4., and 8.3.5. because they add nothing to the
discussion of wind correction.  Instead, replace the deleted 8.3.3. with the

"Any visible deviation from the correct geometry of a figure as defined by
aircraft attitude or flightpath, as appropriate, will be downgraded according
to the criteria described in this chapter."

Replace deleted 8.3.4. with the following:

"There are no downgrades required by this Chapter for sideways movement of an
aircraft unless that sideways motion is accompanied by an incorrect flight
attitude which contributes to that sideways motion."

Regarding criteria for "Loops and Part-Loops," change paragraph as

"A loop must have, by definition, a constant radius, and be flown in the same
vertical plane throughout.  The vertical plane in which a loop is to be flown
defines the airplane's attitude and therefore any sideways drift during a
loop or part-loop is not to be downgraded.  Wind correction in loops is for
purposes of maintaining constant radius only.  It starts and ends in a well
defined line which for a complete loop...."

The purpose of this change is lay to rest the arguement that the reference in
this paragraph to the vertical plane which defines the loop means that the
competitor must wind correct for not only radius of the loop, but also for
lateral displacement in looping figures.  Some persons believe that a loop
flown with a crosswind must not only be round as defined by the radius, but
also must also close precisely over the spot on the ground where it started
by correcting for the sideways motion of the airplane caused by the crosswind
(all the time without changing the perfect attitude; i.e. imparting yaw to
counteract the crosswind).

Family 2.3 - 2.15 - Rolling Turns

Change the deduction for rolling turns by adding the "no more than" to items
1 and 4 as follows:

1. Constant rate of roll (no more than one (1) point deduction per
4. No recognizable variation in the rate of turn (no more than one (1) point
off for each).

The purpose of this change is because the downgrade criteria make no
allowance for the magnitude of the variations and in the opinion of many are
excessively harsh.  Also, I don't want to hear another U.S. Nationals judges
briefing in which judges are urged to deviate from the prescribed criteria
for judging figures as defined by our red rule book becuase people don't
agree with the criteria.  That sets a bad example and has occurred during the
briefing for the last two National contests.  Let's change the rule instead.

Family 5 - Hammerheads

Make a correction to the third paragraph which would mirror that discussed
above regarding loops in which the "vertical plane" is again mentioned.
 Change the paragraph to read as follows:

"As the aircraft nears the point where it would stop, it must pivot in the
vertical plane around an axis whihc must not be further from its center of
gravity than the wingtips.  The nose and tail exchange their attitudes while
maintaining the same vertial plane.  The vertical plane defines the
airplane's attitude rather than flightpath and therefore any movement of the
aircraft not caused by incorrect attitude in reference to this plane is not
to be downgraded."

Family 7 - Loops, Ss, and 8s

Make a clarification regarding the "vertical plane" references.  Modify the
first paragraph as follows:

"...there will be variations of speed and variations of angular velocity.
 The loop must be flown in one vertical plane.  The vertical plane in which a
loop or part-loop is to be flown defines the airplane's attitude and
therefore any sideways drift during a loop or part-loop is not to be
downgraded.  The circular loop must be wind corrected to maintain constant

The purpose of this change is to again clarify that the wind correction of
loops and part-loop is for maintenance of the radius only.

In addition, IAC should adopt a policy that Intermediate Known sequences must
include a verical roll of one-quarter turn ( and at least one
combination roll (e.g., 1.1.1+

Thanks for your consideration of these proposed changes.

Andrew A. Lundgren
IAC #12502


© Dr. Günther Eichhorn
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