Tiny Surveillance Aircraft To Fly In Tucson

MAVs are tiny, radio-controlled airplanes — less than six inches in diameter — that carry video cameras. They're designed for reconnaissance missions and can be used for search-and-rescue, law enforcement, military surveillance, or in any situation (such as a nuclear power plant breakdown) where sending in a human observer might be dangerous.

MAVs are silent beyond 50 or 60 feet and their small size makes them difficult to bring down if they are detected.

MAV pilots usually wear goggles that receive video images from the plane, allowing them to fly the aircraft as though they're sitting inside its microscopic cockpit.

The flying part of the competition will be held on Saturday, April 10, at the International Modelplex Park Assoc. (TIMPA) flying field, a city-owned airport for radio-controlled models west of Tucson. If rain or wind prevent competing on Saturday, the flying events will be held on Sunday, April 11.

AeroVironment Engineer Discusses Company's MAVsThe competition begins Friday, April 9 at 5:30 p.m. with refreshments in the Aerospace and Mechanical Engineering (AME) Building courtyard on the University of Arizona campus. (Northeast corner of Speedway Blvd. and Mountain Ave.) Opening ceremonies begin at 6 p.m. in Room S202 of the AME building.

Joel M. Grasmeyer, an aeromechancial engineer from AeroVironment, Inc., will give the keynote address, detailing the company's experience with MAVs and high-altitude endurance aircraft.

Each team will then make a short presentation, explaining its aircraft and the design issues involved. Martin R. Waszak, senior research engineer with NASA Langley Research Center, also will talk about the future of MAVs and the kinds of entries NASA hopes to see in next year's competition.

Ornithopers are New to Event this YearSaturday's flying events begin at 7 a.m. with ornithopters, which are new to the competition this year. These airplanes have flapping wings and mimic the flight of insects and birds.

The competition centers on building the smallest radio-controlled ornithopter that can fly the most laps around a pylon course during a two-minute period. The pylons are spaced about 40 feet apart and the ornithopters can fly an elliptical course around them or a figure 8 through them. The figure 8 laps are worth twice as many points as elliptical laps, giving the edge to maneuverablity rather than top speed. The final score is calculated by dividing the number of laps flown by the ornithopter's largest dimension squared.

MAVs to Fly Two EventsThe MAV competition begins at 9 a.m. and has two parts — surveillance and endurance.

During the surveillance competition, the objective is to fly the smallest MAV that can return a legible image of a symbol located about 4/10ths of a mile (600 meters) away from the launch point. The symbol, which is about five feet high, is enclosed in a 5-foot-high fence that is 12 feet on a side.

The endurance competition involves building the smallest MAV that can fly for the longest time, up to 15 minutes. The winner is determined by dividing the flight time by the MAV's largest linear dimension cubed. In the event of a tie, the lightest plane wins.

Teams also are judged on a technical paper submitted before the competition that summarizes their design effort.

The overall winner is determined by the combination of scores from all the events. UA's Micro Air Vehicle Club, which is hosting this year's event, placed third out of 12 teams in last year's competition.

MAV Design is not Trivial"The problems that MAV teams must solve to be successful are very difficult," said Assistant Professor Sergey Shkarayev, advisor to UA's MAV Club. Research into optimal airfoil design for MAVs already has resulted in two master's theses at UA, he noted, and future graduate research probably will focus on propeller design and ultralight control mechanisms.

He and his students discovered that slight changes in airfoil shape can mean the difference between high performance and a plane that won't fly at all. "We designed and flew a 12-inch airplane and then decided to modify it slightly by making it a little longer and slightly decreasing the reflex (upward turn) along the trailing edge of the wing," he said.

From a seat-of-the-pants, geometrical perspective and from experience with conventional airfoils, this looked like a simple change. The result was a plane that wouldn't fly. "Only when we cut off two millimeters on the trailing edge and returned to the reflex shape we had found to be optimal did the plane fly," Shkarayev said.

The 8th International MAV Competition is sponsored by:

• Advanced Ceramics Research

• AeroVironment, Inc.

• American Institute of Aeronautics and Astronautics (AIAA)

• Boeing

• FMA Direct

• NASA

• The New Nose Co., Inc.

• Raytheon