Concerns over risky aerial engagements were spotlighted after a Chinese fighter jet came within 9 meters (30 feet) of a U.S. Navy P-8 Poseidon plane over the South China Sea in August. The ongoing feud over control of the islands has sparked fears of a collision or shoot-down, with Japan saying it has boosted jet scramblings by almost 30 percent in response to approaches by Chinese planes. Robinson said the U.S.