The National Society of Radio Controlled Aerobatics (NSRCA) is the US Special Interest Group (SIG) that supports and encourages R/C indoor pattern through its newsletter, website and the organization of competitions in the United States. You can find more information about the NSRCA www.nsrca.us.
The F3P acronym stands for:
F = Flying model
3 = Radio control
P = Indoor Aerobatics
The Federation Aeronautique Internationale (FAI) class of F3P is an aerobatic event for radio controlled model aircraft flown indoors. Competitors fly a complex sequence of known manoeuvres to the highest degree of precision possible. Judges are positioned immediately behind the pilot and evaluate the quality of each manoeuvre. The manoeuvre sequences are designed to be flow in spaces as small as 130 x 65 x 25’, but national and international competitions typically are flown in larger spaces.
F3P models are allowed to be up to 2 meters (78.74”) in wingspan and length, but can not exceed 300 grams weight (10.58 ounces). Any powerplant may be used so long as it does not generate any kind of emissions, or exceed 42 volts. Construction materials generally used are foam, carbon fiber, and mylar. At the 2013 World Championships, the average F3P model was 39” long, 34” wingspan, and approximately 70 – 125 grams (2.5 – 4.4 ounces). Two-cell lipos were used by all competitors for power supply, with the top models using counter-rotating coaxial motor systems. At the 2015 World Championships, some aircraft are expected to weigh just under 40 grams with power supplied by one-cell lipo, and two-cell lipo aircraft will weigh in at 60 +/- grams.
The F3P class is a team and an individual competition. FAI member countries may enter a team of up to 3 competitors as a national team for world and continental championships. Team results are the sum of the three competitors' scores at the end of the contest. Countries may also elect to send a Junior (18 years old or younger during the year of the contest) team member.
Even though takeoffs and landings are not judged, F3P models must takeoff and land on the “runway” without assistance. After takeoff, a maximum of two 180 degree turns are permitted prior to commencing the aerobatic sequence. An F3P sequence consists of six center manoeuvres and five end (turnaround) manoeuvres, all of which are judged. The manoeuvres include elements and combinations of lines, loops, rolls, knife-edge, stall turns, torque rolls, and tail slides.
Each competitor will be entitled to four preliminary flights, of which the best three normalized scores will determine his placing. For each flight, the highest score will be set equal to 1,000 points, and the remaining competitors scores will be equate to a percentage of the highest score. For preliminary flights, the “AP-xx” sequence is flown, where xx is the year of the world championship.
At world and continental championships (and optionally at larger national competitions), the top 25% of pilots (minimum of 10) complete three additional finals flights using the “AF-xx” sequence. The total of the best three preliminary flights is normalized to 1,000 points and counted as a single score. This single score and the three finals scores give four normalized scores. The sum of the best three normalized scores is used to determine the final placements. The fourth score is only utilized in the case of a tie.
The competitor's performance is assessed by a panel of judges who will award marks, independently from each other, between 0 and 10 for each manoeuvre. Manoeuvres are assigned a difficulty factor (K-factor, which is a multiplier applied to each manoeuvres) depending on the complexity of the particular manoeuvre. Judging is based on four basic criteria: precision (or geometry), smoothness and gracefulness, positioning (display), and size of manoeuvres. Points are subtracted for various types of defects observed by the judges, the severity of these defects, and the number of times these defects are observed. Should the aircraft touch the walls, floor, or ceiling, the manoeuvre being performed is scored a zero.
Also included in the F3P class is a separate event; Aerobatics Freestyle to Music (AFM). AFM is a timed 2 minute aerobatic flight choreographed to music. Scoring, from 0 – 10, is completed for each of three categories; flying style, artistic quality, and overall impression. Flying style includes the elements of precision, effective use of the full flight envelope, and innovation of new manoeuvres and manoeuvre combinations. The highest scores for artistic quality will be earned when the music includes fast and slow segments and a broad dynamic range, and the flying is well choreographed and synchronized to match the music. Overall impression considers the use of the entire flight area, the use of special effects, interaction and reaction of the crowd, and the fluidity of transitions. Typically, participation in AFM is limited to the top 50% of competitors in the pattern segment (AP-xx and AF-xx).
Here you can see the 2 different sequences that will be flown during the 2015 World Championships in Poland.
And some examples of AFM:
By Dave Lockhart, November 2018 K-Factor
By Greyson Pritchett, December 2018 K-Factor
By Bill Pritchett, August 2018 K-Factor