Chapter 107 of the International Aerobatic Club (IAC) has announced that Brady’s Curtis Field is the site for its first annual Hill Country Hammerfest Aerobatic Contest on March 29-31. This regional aerobatic competition is expected to draw approximately 25 to 30 aerobatic pilots and their aircrafts from Texas, Louisiana and Oklahoma. Pilots will compete in one of five categories ranging in difficulty from basic, sportsman, intermediate, and advanced through unlimited. The Hammerfest, will begin on Thursday, March 29 with the arrival of competitors. Practice flights will be flown throughout the day in the aerobatic box located immediately adjacent to the west of Curtis Field. The competition flights will begin at 8 a.m. Friday, March 30 and continue until sunset, and will resume at 8 a.m. on Saturday, until sunset. An awards ceremony will be held at the Brady VFW hall Saturday evening. The general public is welcome and encouraged to attend, but this event is not an “airshow.” The aerobatic sequences flown in the competition are designed to demonstrate pilots’ abilities to fly precisely and safely, and are not necessarily designed for entertainment value. There are few sports that demand as much physically and mentally from the participants as sport aerobatics. The competition sequences, as the flights are called, must be flown with split-second timing, precise speed and altitude control, constant calculation for such variables as wind and temperature, and very precise planning on the pilot’s part. Any wrong turn, misplaced pullout, and roll in the wrong direction can put the pilot out of the running because of a zero score by the judge. The sequences are flown in an aerobatic zone over the airport commonly called the “Box.” This box is an area 3,300 feet square with the top at 3,500 feet. The bottom of the box varies according to the competition category. For Sportsman pilots, it is 1,500 feet – for unlimited it is 328 feet. The flights are graded by a team of five judges who are assisted by two people each. These judges grade each individual figure as well as how well the sequence is positioned within the box. The figures are graded on such factors as precision of the lines and angles, symmetry of figures and other factors spelled out in the IAC “Official Contest Rules.” Each Judge has a copy of the figures the pilot will fly. On these sheets the figures are graphically represented by symbols. The system of graphically depicting the figures was devised by Jose L. Aresti of Spain for use in world aerobatic competitions. It has been successfully used for many years. Since 1988, the FAI Aerobatic Catalogue has been in use. In addition to the graphical symbol, each figure is assigned a difficulty coefficient of “K factor” based on the difficulty involved in performing the figure. The Judges, in turn, grade the figure on a scale of 0 to 10. The K factor and grade are multiplied to derive the points for that figure. A computer then adjusts the totals to account for bias. Each competition category’Basic, Sportsman, Intermediate, Advanced and Unlimited (in powered aerobatics)’flies a different set of sequences. The greatest number of pilots will be flying in the Sportsman category. It is IAC’s most popular and where the competition is most keen due to the great number of entries in that category. There is also an even more simplified entry-level category called Basic. Although the sport of aerobatics is relatively new in aviation, the excitement and spectacular action of these magnificent aircraft doing the precision aerial ballet under the most difficult environmental conditions for the pilot has destined the sport to become one of the most interesting in aviation. Questions regarding IAC or aerobatic competition should be directed to International Aerobatic Club, P.O. Box 3086-H, Oshkosh, WI 54903-3086.