LAX99LA113

The pilot was ferrying the Thai-registered aircraft from Thailand to the United States mainland. After departing Honolulu, when the aircraft was approximately 810 nautical miles northeast of Hawaii, the pilot noticed that the engine oil pressure was decreasing and reversed course back to Hawaii. Over the next 3 hours the pilot reported decreasing engine oil pressure, increasing temperatures, and decreasing engine manifold pressure. When 345 miles from Hawaii, the pilot advised the flight crew of an escorting U.S. Coast Guard C-130 that an engine failure was imminent and that he would need to ditch the aircraft. The Coast Guard crew advised the pilot of the best procedures for making an approach into water. The pilot then made an emergency descent and ditched the aircraft. The aircraft bounced off a swell, then hit another, and nosed down. The aircraft remained afloat in an upright position for about 45 minutes before sinking. The aircraft doors were not opened and the pilot was not observed in the water after ditching. The C-130 loitered over the ditched aircraft until it disappeared. The pilot and aircraft were not recovered. The government of Thailand delegated the accident investigation to the NTSB.

On February 28, 1999, at 1240 hours Hawaiian standard time, a Cessna P210N, Thai registration HSKCC, ditched in the Pacific Ocean approximately 345 miles northeast of Maui, Hawaii. The aircraft remained afloat for about 45 minutes before sinking. The airline transport pilot was not observed in the water after ditching and is presumed to have suffered fatal injuries. The aircraft was operated by Pilot Services International, Ltd., and the flight was conducted under the provisions of 14 CFR Part 91 as a ferry flight. The aircraft departed the Honolulu, Hawaii, airport, about 0500, and was en route to Hayward, California. An instrument flight rules (IFR) flight plan was filed and visual meteorological conditions prevailed.

The National Transportation Safety Board offered to conduct the accident investigation for the Thailand Department of Aviation in accordance with ICAO Annex 13, paragraphs 5.3 and 5.3.1. The Department of Aviation accepted the offer on March 18, 1999.

The pilot ferried the aircraft from Bangkok, Thailand, to Honolulu on February 18, 1999. He then departed Honolulu en route to Hayward. At 0933, when the aircraft was approximately 810 nautical miles northeast of Oahu, Hawaii, the pilot first radioed that the engine oil pressure was decreasing and that he was returning to Honolulu. At 1006, the pilot radioed that the oil pressure was 10 pounds above the lower red line limit, there was no increase in temperature, and that the cabin was depressurizing. At 1026, the pilot reported that the oil pressure was on the red line and the temperature was increasing. At 1036, he reported the oil pressure was continuing to drop and that the manifold pressure was decreasing. He believed that the engine turbocharger was failing. At 1043, the pilot radioed that the engine was operating at normally aspirated manifold pressure level and that some temperature had increased by 10 (degrees). At 1206, the pilot radioed that the engine oil pressure was one needle width below the red line, (a) temperature had increased slightly and manifold pressure was 22 inches.

A U.S. Air Force KC-135 aircraft diverted from its course at 0949 and initially escorted the aircraft. A U.S. Coast Guard C-130 later relieved the KC-135. At 1234, the pilot advised the C-130 flight crew that an engine failure was imminent and that he would need to ditch the aircraft. The flight crew advised the pilot of the best procedures for making an approach into water. The pilot then made an emergency descent and ditched the aircraft. A USCG officer reported that the aircraft bounced off a swell, then hit another, and nosed down. The aircraft remained afloat in an upright position for about 45 minutes before sinking. The Coast Guard officer reported that the aircraft doors were not opened and the pilot was not observed in the water after ditching. The C-130 continued to fly over the ditched aircraft until it disappeared.

According to the USCG, weather at the site was approximately 1,500 foot scattered, 1,700 foot broken ceiling, visibility 20 miles with surface wind from the south at 5 knots. The sea swell was from the north-northwest at 6 to 9 feet. The aircraft ditched on a southwesterly heading.

The ocean depth is approximately 18,000 feet. The aircraft was not recovered.

The aircraft was previously registered as N83HM in 1982.