Radio Control Aerobatics
Albert and A.C. Glenn [[email protected]]
Last year's F3A World Championship
In this month's column, we cover more of the airplane "Whisperer," include a report on the F3A World Championship, and Albert (aka "the Dog") writes "What the Dog Saw."
As the team manager, I thank all those who supported the US team. We finished third (winning the Bronze) in Pombal, Portugal, against some outstanding competitors from all over the world.
The French team rose to the top. A performance by former world champion Christophe Paysant-Le Roux bordered on perfection; he won all but one round.
More incredible was his fellow teammate and brother, Benoit Paysant-Le Roux, who won the Silver Medal and helped the French defeat the Japanese. The Japanese team had three pilots in the final round, versus two for the French team.
The US team had two pilots in the Finals, but only one counting toward the team score. Jason Shulman finished sixth and Andrew Jesky finished 11th, barely missing the top 10 after being there until the last round of the semifinals. Brett Wickizer finished 13th in his first World Championship.
Defending world champion Quique Somenzini, who finished seventh, floated between the second and third spots in the Preliminary and Semifinal rounds. The Finals were different; Quique threw the dice in the last round of Unknowns, and it lowered his position.
The US had the largest team of pilots and supporters at the World Championship. Attendees put forth a huge effort toward trying to bring home the Gold.
In 2011, the F3A World Championship will be held in Muncie, Indiana, at the International Aeromodeling Center. It will require that same high level of support for the US to rise to the top and put on a world-class event.
Thank you to the Portugal World Championship Committee and to the wonderful hospitality of the people in Pombal and Portugal, who made this World Championship one of the best.
What the Dog Saw in 2009:
- The complexities of the maneuvers in FAI are becoming more difficult to fly, but even more so to judge.
- The organizing and judging at contests are at a high level, but inconsistency still exists and creates barriers to increasing consistent participation.
- In AMA and FAI classes, some pilots are better than their airplanes. Trimming aircraft seems to be a lost art in the world of ARFs, and pilots with outstanding skills are flying models that need trimming.
- Electric-powered aircraft at the F3A World Championship were the majority, but glow power still won the contest and was used by half of the pilots in the Finals. The latest versions of glow engines seem to be as reliable as electric for those in the Finals. I don't know the numbers at the AMA Nats, but I would guess that the ease of electric power makes it the main power source in the US.
- Aerodynamic aircraft aids to make the vertical stabilizer and rudder more effective — and biplanes — seem to be answers to the more demanding maneuvers. T-canalizers, dorsal fins, small V-tail wings, dorsal strake, and new biplanes are the latest changes.
- We now have a large choice of reliable and reasonably priced, high-quality radio systems, batteries, and new ARFs that are within most pilots' reach. It now costs less to purchase an ARF than it does to scratch-build an F3A airplane.
- The Europeans have a Europe Championship; it would be to the advantage of the US aerobatics community to promote an America's Championship in the off-World-Championship year to develop pilots and judges.
- There is often news about unmanned aerial vehicles (UAVs). Maybe our sport should be "Precision UAV Aerobatics." This might attract new sponsors and a higher level of business interest.
That's all from the Dog. If you have comments or photos for use in the column, please send them to our e-mail address.
The Airplane Whisperer
In the November column, we published the first installment — by Bryan Hebert — of this new series. Following is the latest from him.
"Here we are again talking about my favorite subject, 'perfect trimming.'
"In the last article, we laid out where we have come from in the evolution of our designs and schedules. We talked about the increases in difficulty that are expected in our setups. I would like to lay the foundation for my trimming methods now and try to explain how to achieve a consistently good flying airplane, without having a master's degree in radio mixing.
"First, because this is a trimming article aimed at Pattern (RC Aerobatics) flying, we will assume you have a greater-than-average understanding of setup, radio installation, and slop-free linkages. It is very important to do the shop work and precise radio setup before you even attempt to start flying and trimming.
"If you are new to the sport and need some basic knowledge, there is a great article written by Dean Pappas called 'Trimming From the Ground Up.' You should read this article by Dean first before attempting to digest any other trimming advice from anyone. [You can find the web address where you can access this article in the 'Sources' list at the end of the column.]
"Now, I've been doing this long enough and helped enough fliers in trimming their aircraft to know that trimming is an art. Even some very good fliers have trouble disciplining themselves to allow the airplane to fly purely, without correction or cheats, while trying to perform simple tasks in the trimming process. Learning how to trim an airplane and being able to duplicate that trimming procedure with another airplane can be laborious work, but in the end, it is worth it.
"Here is the goal we are trying to achieve, and to do it these rules must be adhered to. What we want is for the airplane to fly itself — yes, fly itself.
"You say, 'Bryan, what do you mean?' Well, I'm glad you asked. Let me explain. The airplane, absent our input, should do what we told it to do last, at all times, even in the wind. That is when we know the trimming process is nearly complete.
"When you pull the airplane into a 45-degree up line, you want the airplane to follow that line as long as possible without correction, not even by using the elevator. The same holds true with a vertical up line or a 45-degree down line. No input at all should be required to maintain the line.
"That is why it's important to be absolutely certain that you have hands-off trimming on a straight horizontal line of flight. You must be certain that you have no adverse trim effects on any line that requires neutral elevator input. This is an achievable goal and should not be overlooked; it is the most important step in the analysis process.
"Let me start by saying you must be as honest with yourself as your skills allow. There is no cheating in aerodynamics; compromises will always show their ugly heads somewhere down the line and usually where it hurts the most. The greatest percentage of the time it is in snaps and spins.
"Here is the first unbendable rule: when all else fails you must remember this — a perfect setup will improve every maneuver in our schedule, from Sportsman to F3A, from stall turn to snap roll.
"So if you think you are finished, and you have a couple of maneuvers that are not quite as good as they used to be, or if you are having trouble hitting a particular maneuver, you either have to tweak your control-throw/expo setup (something often overlooked after an adjustment) or you still have something out of whack!
"A real improvement will correct more than one maneuver. It will usually change, to the good, all maneuvers. So, let's get started, shall we?
"Bench trimming: This cannot be stressed enough; you must be as precise as possible in your base setup. You must know where your actual starting point lies. You need to be sure of your wing incidence in degrees, down thrust of the motor in degrees, and C/G position.
"Another very important step is to know the exact throw, in degrees, of all control surfaces. What we are talking about here is the actual amount of deflection for every moveable surface. We call this the control throw, or just throw, of the surfaces.
"Now, check, re-check, and duplicate every setting until you can be certain of these parameters every time. One of the biggest problems I encounter while helping pilots trim their airplanes is that they are not aware of the throw and incidence settings of their airplane control surfaces and wings.
"Many airplanes have been cut and twisted in order to fix a so-called bad flying airplane. Some have even been redesigned due to bad diagnosis regarding unexpected performance, such as finding that an airplane which will not snap or spin, when the only problems were incorrect throws and incidence, or the C/G was not correctly set.
"Every airplane requires a slightly different setup in the amount of control-surface throws for spins and snaps. That is why it is so important to set a baseline of settings (incidences, throws, and C/G) for all non-input flying such as level flight, vertical flight, and single-input flight (like knife-edge flight and inverted flight).
"Without these maneuvers being flown hands-off, or at least flying with very limited input, it is impossible to have a base upon which to build your inputs for the complex maneuvers. The small imperfections in trim will turn into big course deflections in the complex maneuvers, requiring large corrective inputs from the pilot. The simple things have to be perfect, just like trying to assemble a maneuver.
"If your straight lines are not straight, then you have no foundation upon which to build perfect geometry. The less you have to apply course corrections to the airplane, the less chance you have of making an incorrect input. Even if you have an airplane that will fly hands-off at numerous angles, knife-edge will be the most important and the hardest to achieve, so pay close attention to all of the steps in your setup."
We will be back next time with another installment of setup tips from Bryan Hebert. MA
Sources
- "Trimming From the Ground Up"
www.modelaircraft.org/MAG/FTGU/Part%2029/29main.html
- National Society of Radio Controlled Aerobatics
Transcribed from original scans by AI. Minor OCR errors may remain.
