Aerial Scramble

Aerial Scramble
Type	Engineering
Category	Build
Latest Appearance	2023
Forum Threads
2023 2022

Aerial Scramble (also called Aerial Scrambler) is a Division B and Division C trial event. It was run in both divisions at the North Carolina and Indiana state tournaments in 2018 and 2019, and in Division B at the Georgia state tournament in 2019. The event requires that teams assemble and fly a rubber-powered airplane on site.

The Event

At the event, competitors will be given two model airplane kits, such as the AMA Alpha. This kit will not require adhesives, and can be disassembled to fly again. The competitors will be given a minimum of 20 minutes to build the airplanes and test them, with the goal of making them fly for as long as possible. At the end of the building/testing time, the competitors will make up to two timed flights, using one or both of their airplanes. Any tools used, as well as any custom rubber or winders, must be brought by the competitors.

Preparation

The competition organizers will announce the kit to be used at the competition at least two weeks in advance, and it is advisable that competitors begin preparing as soon as it is announced, if not sooner. Competitors should procure at least one kit for testing, and possibly another to use when practicing the building. It may be beneficial to practice building generic kits even before the announcement of the official one, to get a feel for (and eventually fine-tune) a speed-building technique. Once the official kit is confirmed, it would be a good idea to build one airplane and test it as one would for a Wright Stuff airplane, testing various adjustments and logging them. This way, the coarse adjustments are already known for the competition day, and one can begin testing fine adjustments for each individual plane during the competition time slot.

Building

It is important to read carefully and follow the directions given in the kit closely. Some general things that are universal across kits is that the planes, if flown indoors, are instructed to be built in a way that makes the airplane fly in left-hand, counter-clockwise circles. This is achieved by numerous factors such as rudder deflection to the left, or tilting the horizontal stabilizer so that the left side is higher than the right (from a back view). With kits such as the AMA Alpha, it is easiest to deflect the rudder by simply bending it a little. However, if the wings and rudder are constructed out of foam, it's important not to bend or stress the foam too much as it can easily become weakened from overuse.

Flying and Trimming

The most important part of this event is being able to make appropriate changes to make your plane fly as long as possible. Please see the Wright Stuff page for a description of proper winding technique and more details regarding trimming. While doing initial flight tests, only wind for about 300-400 times (around 25 turns on a 15:1 ratio winder, or 20 on a 20:1 ratio winder as provided in the Alpha Kit) as there is limited time to fly. Add more winds once your plane flies smoothly.

Diving

If the plane seems to be immediately nosediving to the ground upon release, raise the wing incidence by making the leading (front) edge of the wing higher than the trailing edge, add ballast (clay) towards the back of the plane to move the center of gravity backward, or try winding a bit more. Test one variable at a time and only make one adjustment before another flight in order to determine which adjustments are most effective.

Stalling

If the plane appears to climb, then immediately drop nose down, then climb again, the plane is stalling. This can be fixed by moving the center of gravity forward by adding ballast toward the front of the plane, lowering the leading edge of the wing, or moving the entire wing rearward on the motorstick.

Rubber Motor

For official flights, the amount of winds will depend on your motor, though it typically is around 1500 winds. While practicing for competition it may be a good idea to experiment with different widths and weights of rubber motors to determine the best combination. The goal is for the plane to land just as it runs out of winds. If the plane runs out of winds too quickly, use a heavier motor or thinner rubber, if it lands with many winds left use a shorter motor or thicker rubber. Instructions given in the kit is a good starting point.

Materials

• Rubber lubricant - Using lubricant such as Armor-All or something similar will allow for more winds to be put into the motor which is imperative for longer times.
• Tools - It's a good idea to bring a set of basic tools such as X-acto knives or razor blades for any adjustments that may be necessary on site.
• Glue - Fast-drying glue like cyanoacrylate would be best in a timed situation to make any repairs.
• Clay - This may be utilized to add ballast to the front or back of the plane and adjust the center of gravity.
• Rubber - While many kits may provide a winder and rubber (as the AMA Alpha does), you may wish to experiment with different widths, as kits general provide only one.
• O-rings - While not completely necessary, these are attached to the motors and make it much easier to transfer the motor from winder to the propeller.
• Logbook - It is required for participants to bring a logbook to competition. Logbooks must include information regarding tasks used to build the plane or to test the plane.

Teams may also bring tools such as winders, sandpaper, and other assets as long as they fit in a container. Always be sure to review the rules before putting this kit together.

Scoring

The final score is calculated by adding the lengths of both flights together. Ties are broken by the longest single flight time.