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Flights of the SCtingray

A Radical Design Proves a Winner for USC Students

September 27, 2006 — A team of USC undergraduate engineering students with a radical flying wing aircraft called “SCtingray” won fourth place at the 2006 Design/Build/Fly International Competition sponsored by the American Institute of Aeronautics and Astronautics.
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The flight team takes a bow. (Click the photo to view)
From left to right, Chris Poblete, George Sechrist (kneeling), Ed Smetak, Jeff Kaiser, Joe Yeargan, Karl Brecht, Sam Ekweghariri, Mark Page, Luke Hardman, Matt Miller, Tomas Campuzano, Suzie Miles, Ron Blackwelder (advisor), Andres Figueroa, Caitlyn Fahey, Lane Dalan, Cristina Figueroa, Ian Whittinghill, Wyatt Sadler (advisor), AllieAnderson, and Ewald Schuster (pilot). Kneeling behind the plane are Tai Merzel, Jessica Calhoun, Tanner Yaberg, and Shweta Shrivastava.

A total of 49 teams entered the competition, held in Wichita, Kansas, but because of the rigors of the construction and competition, only 41 planes from the U.S., Israel, Turkey and Canada actually flew.  All of the planes were radio-controlled and equipped with battery-powered electric motors. Each aircraft had to fit in a 2 x 4 x 1.25-foot packing crate, take-off within 100 feet of launching and fly with three diverse payloads.

“I’m really proud of these students,” said faculty advisor Ron Blackwelder, professor of aerospace and mechanical engineering.  “USC has entered this competition each year during the last nine years and has placed first once, finished second twice, and was third twice in addition to placing fourth this year.  The rules change every year, and the competition gets tougher and tougher.”

The 2006 competition emphasized transporting cargo.  After passing a rigorous safety inspection, each team was asked to complete two different types of missions with their aircraft.  In the first, the plane carried 96 tennis balls for two laps.

“Almost all the teams chose to fly only 48 tennis balls at one time, necessitating landing and loading the additional 48 balls for a second flight of two laps,” said Blackwelder. 

In the second mission, the plane had to demonstrate it could fly with three different types of cargo.  It had to do one lap each with 48 tennis balls, four liters of water and a 2-foot-long, 4 x 4-inch block of wood.

"Ole Foamy" tested a radical design blending the wings with the body of the aircraft.

“The scoring for this mission was based upon the time required to exchange the cargo while on the ground,” Blackwelder explained. “The planes had to take off within 100 feet and fly around a 1,000-foot pylon course with additional turns to demonstrate maneuverability.  Since the planes were all limited to less than three pounds of batteries, energy management was an extremely important part of the design and flying, in addition to the need for a versatile cargo bay.” 

Blackwelder said that an added degree of difficulty was introduced into the competition by the weather, namely Wichita’s notorious gusty winds.

The total score for each team was determined by their best flight performances on the two missions, their score on a written report documenting the aircraft design and selection, and a "rated aircraft cost" representing the weight of their plane. USC’s ‘SCtingray came fourth in the flying score and the team placed third in the written report section.
The design/build/fly competition is a project that involves student participation over an entire school year, with teams forming in the fall to design and build the aircraft for the spring competition.  Following a thorough examination of the rules, the Viterbi team decided they would attempt a design that blended the wings with the body of the aircraft.

“They needed a light weight plane that would have a voluminous cargo area,” said Blackwelder. “This radical design required developing several new design and manufacturing tools. The aerodynamics proved especially difficult due to the extreme amounts of twist that had to be added to the wing to satisfy the control constraints.”

Although a panel of engineers from industry who reviewed the Viterbi students’ initial design was skeptical, the team decided to forge ahead. They quickly built a full-size model out of a big block of foam.

Some quick adjustments were needed during competition.

This model, called ‘Ole Foamy,’ proved that the flying wing concept was not only sound but promised to be a strong competitor.  Its stability and controllability far exceeded the team’s expectations, so they proceeded with construction of the final plane.

When the aircraft was completed, the students conducted systematic sets of flights on weekends to insure the aircraft had sufficient power and endurance, could take off within the prescribed distance and would allow a quick payload exchange.  They simulated the required missions for the competition.

The team leader of the 2006 team was Tai Merzel, an aerospace major.  His team consisted of 20 aerospace students, nine mechanical engineering students, and eight other engineering students from different departments. The team had two industry advisers, Mark Page from Swift Engineering, Inc. and Wyatt Sadler from Aerovironment, Inc.

The team’s organizational structure  was modeled after industry. There were discipline groups for aerodynamics, stability and control, propulsion, etc, with each responsible for designing a sub-component of the aircraft. Each group was required to provide a written description of its effort for the written report part of the compettion.

Freshmen and sophomores usually team up with upperclassmen, with juniors and seniors serving as group captains, Blackwelder said.  Thus, all of the students got experience working on teams and older members gained leadership experience.

Up, up and away.

The team usually visits local industry to present their project to working industrial engineers, thus providing students with experience in technical presentations and oral communication.

The annual competition was supported by Cessna and the Office of Naval Research to promote aerospace engineering and aircraft development in undergraduate educational programs.