The missing aircraft, a Boeing 737 operated by Karachi-based K2 Airways, was flying from Sharjah in the United Arab Emirates to Karachi when it reported a navigation system malfunction at around 9.18 pm local time, according to Pakistan's airport authority. Officials said radar data showed the aircraft suddenly descending and making a sharp change in direction at around 9.21 pm. Moments later, both radar and radio contact were lost about 155 nautical miles west of Karachi.