By Cho Jin-seo
Staff Reporter
Making airplanes is not an easy job even for technologically advanced countries like Japan and Germany. Making airplanes that fly without a pilot is more difficult, and making airplanes that fly without a pilot and can go either horizontally and vertically is far trickier. Still, scientists and engineers at Korea Aerospace Research Institute have been developing such a plane on a small budget.
The year 2008 will be a crucial time in determining whether KARI's ambitious plan of making a tilt-rotor unmanned air vehicle (UAV) will bear fruit. In November, KARI demonstrated that it may become the leader in the field by successfully flying a prototype plane, that is about 40 percent in size of the full-sized plane, scheduled to be built in 2009.
``The next step is to mount satellite positioning systems onto the plane,'' said Koo Sam-ok, the chief systems evaluator for the Smart UAV project. But it is relatively an easy job compared to making the tilt-rotor work, he said.
``It's just like the computer game `Mine Sweeper','' he told The Korea Times. ``We don't know what kind of risks lay ahead because it is uncharted territory. I think we have so far swept up most of mines hidden in the main road, but we still don't know whether there are more mines left on the side roads.''
The test was carried out in Goheung, South Jeolla Province. The 2-meter-long UAV with a wing span of 2.8 meters flew for about 20 minutes, and boasted its maximum speed of 140 kilometers per hour until it safely landed on the ground.
Koo said the most difficult part is the lack of information. Korea and the United States are the only two nations in the world that are working on the tilt-rotor UAVs, and not surprisingly, the United States is not willing to share its know-how with other countries, Koo says.
Unmanned aircrafts, in general, have been in use in both military and civilian purposes for more than a decade. The U.S. armed forces are the most frequent user of such vehicles, as they have deployed various versions of UAVs like the Predator and Global Hawk in Iraq and Afghanistan in scouting and bombing missions in dangerous zones with heavy artillery fire. But the scope of the UAVs is relatively limited, as they need a runway to take off and land while the helicopter type cannot fly far and fast enough to efficiently survive enemy fire. The tilt-rotor technology is believed to be able to solve the geographical problem.
As the name implies, a tilt-rotor aircraft uses a pair of tilting (rotating) propellers, for lift and propulsion. For vertical flight the propellers are angled vertically to direct their thrust downwards, providing lift, just like a helicopter. As the craft gains speed, the propellers are slowly tilted forward, eventually becoming perpendicular to the ground. In this mode the wing provides the lift, and the tilt-rotor gives the propulsion, like a turboprop aircraft. The trickiest part is to maintain balance while the rotor is tilting, and Koo's team has succeeded in doing that in November's demonstration.
The versatility of a tilt-rotor aircraft makes it an ideal device in mountainous regions such as Korea. The only commercially successful tilt-rotor vehicle was V-22 Osprey, which has been mainly used by U.S. Marine Corps and also appeared in the movie ``Transformer'' last year. Bell, the company that makes Osprey, is the one of two entities that is developing an unmanned version, along with KARI.
For KARI, it will take at least three to four years to have a commercial product, Koo expects. Its main obstacles are money and pessimism. The 10-year project is receiving 10 billion won every year from the Ministry of Commerce, Industry and Energy, but many people have shown cynical responses to the potential of the tilt-rotor UAV project, Koo said.
``For ordinary projects, 10 billion won per year may be enough. But for an aerospace project, it's not enough,'' he said. ``The project can benefit not only KARI but also many related industries and schools. One of our missions is to convince those people.''
indizio@koreatimes.co.kr