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Redbook Review – November: Rolls and Radii

Posted by tl3
Posted on 11/8/2017

November 2017 Issue 8

There are those who profess that a perfect one-roll rolling turn demonstrates mastery of all flight axes and conditions represented in Scale Aerobatics flight.  I am not going to argue that, but I will place on an equal pedestal – if not maybe slightly above – a down loop with roll combinations at the bottom.  For many pilots, nothing makes the “check drawers light” blink on quite like having to perform a loop towards the ground and start rolling through the radius while they’re still headed down.  I know, this is supposed to be about judging, I’m getting there.   As difficult as these maneuvers are to fly well, they can also be quite challenging to accurately judge, particularly if you’re not entirely up to speed on the criteria for judging roll elements through a loop or part loop.  So here’s a little refresher on loops, part loops (both up and down), and how to properly judge those integrated roll elements. Oh, and in case you haven’t noticed, there might be some down loops in the 2018 Known sequences.

nov_grahpic_1There are numerous figures in both families 7 and 8 where pilots and judges may encounter roll elements integrated into loops or part loops (those ISC guys are a little twisted). In other words, the roll must be flown “on the arc of the loop.” As a judge, when you are faced with these figures, it is helpful to break them into their layered components.

1) Judge the base figure: The first and primary level of assessment is of the geometric base figure on which the roll elements are placed. If it’s a loop (7.4.1), for example, the judge must grade for roll axis errors (wings level), altitude and track changes on the entry line, radius changes, flat spots, perpendicular track displacement (corkscrewing), and the entire figure being completed in the vertical plane.

2) Judge the roll elements: Now that we’ve accounted for the base figure it’s time to judge the roll element(s), which can also be broken down into multiple additional layers: How the elements are integrated into the loop, and the criteria specific to the particular roll(s).

A) ALL roll elements that appear on loops or part loops are required to be integrated into the radius of the loop. If we look at a full inside loop ( with a full aileron roll ( on top, there are two fundamental aspects of grading the roll element that relate to the loop criteria: The entire roll element must be centered at the apex of the loop, and the roll element must continue the established radius of the loop.

B) Once the criteria related to the base figure have been applied to the roll elements, judges must account for the criteria that apply specifically to the type of roll, i.e. hesitation rolls, aileron rolls, or snap rolls.


There are, of course, a few other intricacies and details of which judges must be cognizant. Roll elements do not necessarily consist of a single roll type, but may be combination elements: Roll and snap, snap and point roll, etc. As previously mentioned, centering on the apex, or bottom, is a very important criterion. Often times, judges, and pilots alike, question how combinations are supposed to be centered. The simplest answer is that the entire combination must have equal lengths before and after the loop apex or bottom. For example, if the combination is a snap then aileron roll, from a centering perspective the only thing that matters is where on the radius the combination starts and where it finishes. Picture a clock face: If the pilot initiates the combination at 2 O-clock, it must finish at 10 O-clock, or vice versa. The pause or change between roll types is irrelevant with respect to centering. 

nov_grahpic_3Snap rolls bring another element of complexity to looping figures. As already established, all roll elements are to be integrated into the radius. Yes, that includes snap rolls. However, we also know that due to the pitch and yaw components, and the partially stalled nature of them, snap rolls may result in lateral and or vertical track displacement upon recovery. As such, when judging snap rolls in looping figures, judges must be aware of and account for this possibility. Due displacement effect, it is possible to have a loop figure that appears to be geometrically flawed if viewed only for entry and exit positions and not judged by means of accounting for the specific deductions. Though exaggerated for effect, the illustration represents how snap displacement can result in a loop exit that differs in both altitude and track than the entry, yet the figure may still meet the criteria for a perfect loop. Please note, however, that this displacement is not a judging criterion in of itself! This is simply a collateral effect of snap rolls that may or may not occur, and if it does there is no deduction for the track displacement directly attributed to the snap element. Conversely, one cannot assume that the lack of displacement indicates an improper snap element.

While the intent of this narrative is to delve a little deeper into the intricacies of Scale Aerobatics rules and clarify some of the not so obvious points, it is not a substitute for the actual rule itself. For the complete text regarding looping figures, please refer to your AMA Scale Aerobatics rulebook, specifically SCA-33 for general loop criteria, SCA-42 for Loops and Eights, and SCA-45 paragraph 8.7.4.a for roll elements flown on the arc of a loop.

It is easy to sit on the couch and describe the layered, or levels approach to judging complex aerobatic figures in intricate detail. However, the reality of real-time judging is a bit different. In actual flight, these “layers” are happening simultaneously, not in a nice tidy step by step fashion. Consequently, a proficient judge must be able to glance at an Aresti figure and or hear the caller announce the figure, and then concurrentlyimage and automatically account for all the levels or layers of complexity. Much like flying these intricate figures, judging them accurately takes time, practice, and dedication to the craft. It sounds a daunting task, but the great news is that we’re entering judging school season, and whether you’ve attended one, none, or twenty, I promise you’ll leave a judging school having learned something about being a better judge, and in turn a better pilot as well. Watch your regional event calendars for judging schools near you, and let’s get 2018 off to a more educated beginning. I hope everyone has a great holiday season; before you know it the time to swap the couch for a judge’s chair will be upon us.

Photo Credit: Curtis Cozier

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