On May 22, 1998, at 2107 hours Pacific daylight time, a Piper PA-28-161, N2480Q, descended into the Pacific ocean after takeoff from the Half Moon Bay, California, airport. The aircraft was destroyed, and the private pilot and three passengers all suffered fatal injuries. The personal flight originated from the Reid-Hillview Airport in San Jose, California, at 1850, and stopped at Half Moon Bay. No flight plan was filed. A pilot-witness who departed from the airport about 30 minutes after the accident aircraft reported the weather conditions as 1,200 feet overcast, with tops at 2,500 feet. The witness also noted that it was a very dark night with only a 10 percent moon illumination. The pilot rented the aircraft from Inbound Aviation at the Reid-Hillview airport, and was to return the aircraft that evening. About 1930, the pilot-witness reported seeing the accident aircraft parked on the ramp at the Half Moon Bay airport when he arrived from San Jose. He stated that he recognized the aircraft as one operated by Inbound Aviation. He further reported that the aircraft was no longer there at 2130 when he departed for San Jose. Employees of a restaurant in Half Moon Bay reported serving four men who matched the descriptions of the men believed to have been onboard the accident aircraft. Several ground witnesses were located on the shore south of the airport just after 2100, and reported that they heard an approaching plane and saw it flying low northbound along the beach. They all said that they could not see what color the plane was, but could see the lights on its wings. The witnesses stated that the engine made a sputtering sound. The airplane continued north and began to climb. The engine made a high pitched whining sound and the plane rolled left and out of their sight. The witnesses then reported they heard a loud crash. They were unable to tell if the aircraft had hit the ocean or land, but were sure that the plane had crashed. The owner of the aircraft issued an ALNOT on March 23, 1998, when he found it missing from the ramp. On that same day, a fisherman in Half Moon Bay pulled aboard a seat that was determined to be from a Piper PA-28. Fragmented human remains were found by search units washed up on shore, with articles of clothing identified by family members as belonging to the pilot. A wallet containing identification from one of the passengers was also later found on the beach. Radar data was retrieved from the Oakland Air Traffic Control Center (ARTCC). Review of the data disclosed a 1200 code secondary beacon at a mode C reported altitude of 300 feet just off the north end of the Half Moon Bay runway at 2103:03. The next 12 beacon returns depicted a climbing left downwind departure that achieved a mode C reported altitude of 1,700 feet. The next and final return displayed a 900-foot altitude at 2106:03. A friend of the pilot reported to the San Mateo County Sheriff's office that she had spoken with the pilot approximately 1645 on the day of the accident. He told her that he was going to fly his "normal route" to Half Moon Bay at 1800, and would be home at approximately 2100. The pilot was supposed to telephone her upon his return; however, she did not hear from the pilot again. The pilot held a private pilot certificate with a single engine land rating. He possessed a third-class medical dated March 10, 1997. According to the Federal Aviation Administration Airman database, none of the other three passengers possessed pilot certificates.