On October 24, 2019, about 2123 Pacific daylight time, Piper PA-28R-180, N4958J, was involved in an accident near Shelter Cove, California. Neither the private pilot and passenger nor the airplane have been located. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal cross-country flight. A witness at the Shelter Cove Airport (0Q5), Shelter Cove, California, reported that she observed the airplane depart about 2100 and noted that it was completely dark with no visible horizon. After the airplane lifted off the runway it made a left turn. No record of a preflight weather briefing, nor air traffic servicers were located, and no flight plan was filed. The airplane did not arrive at its destination, Gnoss Field Airport (DVO), Novato, California, and was reported overdue by family. On November 3, 2019, the search for the missing airplane was suspended; there was no wreckage debris located during the search. The Federal Aviation Administration found no evidence of automated dependent-surveillance-broadcast information transmitted from the airplane. Air traffic control flight track data revealed that the accident airplane first appeared in track data about 2.8 nautical miles southeast of Shelter Cove about 2104 and over the ocean. The airplane was at an indicated altitude of about 3,325 ft mean sea level (msl) and was transmitting a beacon code of 1200. The airplane maneuvered and made a right 360o turn followed by a left 360o turn. It then reversed course, conducted a figure-eight turn, and headed south-southeast bound, gradually climbing to about 6,000 ft msl before entering a left descending turn and rapidly losing altitude. The track data indicated that the airplane descended from about 5,800 ft to 2,850 ft msl in the last 24 seconds of recorded track data. The track data was lost about 2123.