First, let's review the rule as written:

4. Aerobatic Airspace:

4.1: X-Axis and Y-Axis
The X-Axis is the main axis of flight, parallel to the flight line. The Y-Axis is perpendicular to the X-Axis (flight line).

4.2: Deadline.
The ―Deadline is located 100 feet (30.5 meters) in front of the contestant. This line delimits the “no-fly” zone for safety reasons. The judges shall zero (0) any maneuver where the aircraft completely crosses this deadline.

4.3: Airspace Control Score 

Judges will evaluate each individual sequence flown, in its entirety, for overall airspace control. Each judged Known and Unknown sequence, shall have one ―figure‖ added to the end of the score sheet, after individually judged maneuvers. This figure shall be known as the Airspace Control Score and will be assigned by each judge. The Airspace Control Score will have a K value dependent on the class flown. This score will then be multiplied by the K Value for the individual class.

The following standard will be used for accessing the pilot‘s performance in maintaining control and awareness of the aerobatic airspace and placing figures in the airspace in a manner that allow the figures to be optimally judges.

The highest standard for Airspace Control will be the pilot that exhibits a significant ability to control the location of the aircraft inside the airspace, relative to the judges, which results in a tight footprint and has the aircraft such that it can be optimally judged at all times. The pilot that exhibits excellent airspace control should receive a ten (10).

The lowest standard for Airspace Control will be the pilot that exhibits a poor ability to control the location of the aircraft inside the airspace, relative to the judges, which results in an excessively large footprint and has the aircraft consistently so far away as to be difficult to properly judge. The pilot that exhibits very poor airspace control should receive a zero (0). Pilots exhibiting airspace control within the range of these two standards will be graded with a range of possible scores from ten (10) to zero (0) in whole point increments.

The K factors for the Airspace Control Score are:

· Basic = 3K
· Sportsman = 6K
· Intermediate = 9K
· Advanced = 12K
· Unlimited = 15K

Airspace Control Score Examined…

Everyone that participates in a competitive event dislikes subjectivity in the rules even though there are sports where almost everything is based on subjective judgments (ie. competitive diving, figure skating, dressage/show jumping, etc). Outside of racing or skeet shooting, most sports contain various pieces and parts that require a consistently applied judgment to render a final result. So it is with our sport of aerobatics.

Many argue that most of our scale aerobatic rules are subjective regardless of our rulebook attempts at the definitive. Judge One’s judgment call that the plane over rotated 20 degrees may be considered only over rotated by 10 degrees by Judge Two. In reality, they were probably both wrong as it only over rotated by 15 degrees but it required them to look at a situation in real time and render an immediate JUDGMENT as to what they saw. Is this subjective or just bad judging? The point is that virtually everything we do in this sport requires some degree of educated judgment to be applied.

Explaining how the airspace control score was developed would fill pages but here is a Cliff Notes version:

1> The inaccuracy of judging an invisible rectangle of air using angled lines is well understand and documented. With larger planes, it forces the pilots to fly further away in order to not violate the angled lines. It really does not work properly in pattern flying either but the size of the aircraft and types of maneuvers used in pattern help negate the issue. There are those that will argue it does “work” but that doesn’t change the laws of physics or math.

2> The old zoned box system inherited from pattern with center line criteria resulted in over weighted centered maneuvers and pilots tended to fly longer end lines to give them time to “set up” and hit the center line.

3> R/C flying fields typically cannot accommodate the use of boundary judges (such as IAC) because of their out of the way locations (unless you want to stand in a river, or a swamp, or a giant corn field, etc). Additional issues with lack of manpower and the fact that at a typical IMAC event there are at least two flight lines in operation take this option out of consideration.

4> We experimented with GPS systems and boundary tracing and the result was interesting but not cost effective nor particularly reliable. The data collected from this experiment was helpful in pointing out just how small an area we had in which to actually fly.

5> We found ourselves with an “aerobatic box” rule in the book that was, for all intents, useless and could not be enforced using any practical cost effect method.

6> The only asset available that could be brought to bear on the issue when all was said and done…was the judge’s eyes and judgment. Although certainly not perfect, it was the place to start.

The ACS was defined very simply:

On a scale of 1 to 10, how well did the pilot demonstrate awareness and control of the airspace used to fly the sequence?

Seems simple enough but it has become obvious that without further guidance as to what constitutes awareness and control, judges have been very reluctant to use their judgment in determining a score. This directly translates into pilots considering the ACS to be a non-issue and even into CDs directing judges to “just give everyone a 10”. Basically, the rule has never been given any chance to impact our flying footprint.

There is no doubt there are more issues at work in dictating our area of flight operations than pilots ignoring the ACS. It is very obvious that sequence design controls about 60% of the airspace used. Weather conditions, pilot skill, and personal flying preferences dictate the remaining 40%.

While the sequence committee works on their part (a very tough challenge!), we as pilots and judges MUST work on our part as well. To that end, let us consider the following checklist as a starting point for developing a sense of consistency with ACS scoring:

1> Does the pilot make obvious their awareness of their airspace? This may be most evidenced by the lack of long across the airspace lines just getting from one figure to another. A pilot that is making an effort to place his figures is usually easily detected by the use of these shorter lines and/or by flying smaller figures.

2> Does the pilot end up at extreme distances in flying the sequences? Does this happen throughout the sequence or just once or twice? In situations where high winds are pushing everyone everywhere, how well is this pilot doing keeping the aircraft in the proper airspace? This is not a wind correcting issue - we already have rules for downgrades as they apply to track. This is more about the ground covered by the aircraft during flight and adjustments made in to accommodate the conditions.

3> Fight the BIAS! Bias is likely to influence any decision when ever natural personal likes and dislikes exist. With “practiced objectivity” it can be subdued to some extent, but in the real world, it generally results in pilots, planes and particular styles of sequence flying that are “liked” getting better marks than those that are “disliked”. Even experienced judges must continuously fight their personal biases to arrive at the best evaluation of the flight.

4> Pilots properly controlling their airspace MAY appear to be “rushed” when compared to what we have become used to seeing over the years.  It is vital that a pilot using the entire airspace (vertically and close in) SHOULD NOT be downgraded as long as they do not break the deadline.  As judges, we have to understand the goal of airspace control and get away from our “comfort zone” of big figures and long lines.  Pilots react to their perception of what type or style of flying will score best with the judges.  To meet our goals, the pilots have to be comfortable with the fact that they are NOT going to get downgraded for flying tighter.