At about 1708 Pacific time, a Piper PA-28R-200 collided with hilly terrain about six miles southwest of Chino while en route from Long Beach to Corona, Calif. The pilot and passenger were killed. Instrument conditions prevailed in the area. The airplane departed Long Beach in VFR conditions with a 1,300-foot overcast. At 1653 the pilot requested a transition through the Fullerton airspace, which was VFR with a 1,700-foot overcast.. At 1700, the pilot requested a frequency change from the Fullerton frequency. The last recorded radar contact was 1707. The Long Beach and Corona airports are separated by a range of low hills, which rise to 1,781 feet msl. The accident site was located at an elevation of about 1,400 feet msl.