A rescuing helicopter flies over China's Antarctic exploration ship "Xuelong" near the estuary of the Yangtze River in east China April 12, 2009. A mechanic was missing and the three other crew members were rescued after the helicopter taking off from China's Antarctic exploration ship "Xuelong" crashed into the East China Sea off Shanghai Sunday. Four crew members, all men, were aboard the helicopter when it crashed near the estuary of the Yangtze River, said a spokesman for the China Marine Search and Rescue Center. [Xinhua]