LAX06FA043

The airplane impacted the ocean following a departure from controlled cruise flight. The airplane had decelerated from 120 knots to approximately 60 knots while maintaining an altitude of 3,500 feet mean sea level (msl), then descended as rapidly as 7,000 feet per minute, finally spiraling toward the ocean in a corkscrew manner before it impacted the water. No pre-accident anomalies were noted with any systems examined, and no distress calls or communications preceded or followed the upset. The autopsy report on the 51-year-old airline transport pilot was consistent with a condition known as left ventricular hypertrophy (LVH), a substantially thickened main heart chamber. It also noted moderate to severe coronary artery disease with evidence of at least one prior small heart attack. The combination of coronary artery disease and LVH would have substantially increased the risk for sudden cardiac death in this pilot. There was no evidence that the pilot was aware of his heart disease. The behavior of the aircraft cannot be explained by any reasonable scenario in which the 11,500-hour pilot was deliberately controlling the aircraft. Therefore, it seems likely that the pilot was unable to control the aircraft, an inability that can reasonably be explained by an incapacitating cardiac event.

History of flight

On November 19, 2005, at 1403 Pacific standard time, a Cessna T210N, N546BC, impacted the Pacific Ocean and sank about 3 miles south of Dana Point, California, following a departure from controlled cruise flight. T.R. Builder Corp. of Newport Beach, California, operated the airplane under the provisions of 14 CFR Part 91 as a personal flight. The airline transport pilot and his three passengers were fatally injured, and the airplane was destroyed. Visual meteorological conditions prevailed and a flight plan was not filed. The flight departed the Brown Field Municipal Airport in San Diego, California, at 1335 and was destined for the John Wayne Airport in Santa Ana, California.

The airplane was not receiving air traffic control services at the time of the accident; however, radar data was obtained from the FAA's Continuous Data Recording (CDR) using the Camp Pendleton Air Surveillance Radar (ASR-9). The flight was utilizing a transponder beacon code of 1200. Using the radar data and wind information provided by the NTSB's weather group, a NTSB vehicle performance specialist conducted an aircraft performance study, which revealed the following information:

The airplane was in level, cruise flight at 3,500 feet mean sea level (msl) and at a calculated airspeed of about 120 knots when at 1359:47, the airspeed began to decrease. The airplane maintained an altitude of 3,500 feet as the calculated airspeed decreased. About 1401:19, the calculated airspeed had decreased to approximately 60 knots when the altitude information showed the airplane depart from level flight, reaching a maximum descent rate of about 7,000 feet per minute down to an altitude of 2,000 feet msl.

There were no distress calls heard over the local radio frequencies or any reports from the pilot after departing the San Diego area.

A witness located on a sailboat approximately 2 miles offshore indicated he looked up and observed an airplane in a nose low attitude spiraling toward the ocean in a corkscrew manner. He believed the airplane was conducting aerobatic maneuvers, but watched for about 10 seconds before realizing it was not going to pull out before impacting the ocean. The airplane impacted the water in the nose low attitude about 100 yards from the boat. The witness and other boat crewmembers boarded a smaller motorized boat and traveled to the impact point. The largest piece of debris located was a door from the cockpit/cabin area. When asked if the airplane was intact as it descended toward the ocean, the witness said he believed it was (mentioning he noticed the tail and the wings). The witness added that he did not hear any engine noise associated with the airplane.

Personnel information

The 51-year-old pilot held an airline transport pilot certificate with single- and multi-engine airplane ratings, and a commercial pilot certificate with single-engine sea and glider ratings. He also held a flight instructor certificate for single-engine, multi-engine, and instrument airplanes. His second-class medical certificate was issued on April 9, 2004, with no limitations.

According to the pilot's last medical certificate application he accumulated a total flight time of 11,000 hours. Review of his latest logbook revealed he logged 409.5 hours since the medical certificate, the majority of which were logged in the accident airplane and a Cessna 310. The last flight recorded in the logbook was on June 27, 2005. The pilot's family provided copies of a calendar he used to record flight time before he transferred the time to the logbook. From July 2005, until November 15, 2005, the pilot posted 124.9 hours mostly in the accident airplane. On March 28, 2005, the pilot satisfactorily completed a flight review as per FAR Part 61.56.

Friends and family of the pilot provided a 72-hour history of his activities prior to the accident. The information provided indicated that on November 16 at 1630, the pilot arrived at the Orange Coast College to teach ground school. His class lasted from 1800 until 2200. He arrived home at 2230 and went to bed at 2300. On November 17, the pilot awoke at 0600 and left for the John Wayne Airport at 0630. At 1630, he finished work and his last flight for the day. After completing some paperwork he arrived home at 1800 and went to bed at 2230. On the 18th of November, the pilot awoke at 0615 and departed for the John Wayne Airport at 0845. He was to fly the accident airplane to Mexico where he was to monitor off-road races in the San Felipe area of Baja California. He cleared Mexican customs at 1030 and tracked a race between 1145 and 1900. About 1900, the pilot refueled the airplane and continued tracking the race between 1945 and 0030 on the 19th. At 0045 on the 19th, he finished flying in San Felipe and went to bed at an unknown time. At 0900 on the 19th, he began preparing the accident airplane for the return trip to John Wayne. At 1300, he arrived at the U.S. customs facility at the Brown Field Municipal Airport in San Diego, California, and departed at 1335 for the last leg of the flight.

According to his family, he did not report any physical problems in the days leading to the accident.

Aircraft information

The accident airplane (serial number 2103663) was equipped with a six-cylinder Continental TSIO-520-R9 engine (serial number 294346-R). Review of the aircraft maintenance records revealed that the airplane underwent its last annual inspection on October 21, 2005, at an airframe and engine total time of 4,801.0 and 642.1 hours, respectively. The total time of the airplane at the time of the accident was 4839.4 hours. The engine underwent a factory rebuild and was zero-timed about 680 hours prior to the accident.

The airplane had undergone a number of modifications, one of which included the installation of a Robinson STOL (Short TakeOff and Landing) kit. According to the STOL kit Supplemental Type Certificate (STC) holder, installation of the equipment and modification of the aircraft does not result in a reduction of stall speed. The system is only intended to increase controllability at slower airspeeds. According to the STC holder, the stall speeds remain the same as published in the pilot operating handbook (POH)/information manual. According to the T210N information manual the stall speed at 4,000 pounds, with the most rearward center of gravity, flaps retracted, and power off, is 67 knots calibrated (68 knots indicated).

Meteorological information

At 1353, the weather observation facility located at the John Wayne Airport reported the wind as variable at 4 knots, visibility 10 statute miles, with clear skies, temperature 28 degrees Celsius, dew point -03 degrees Celsius, and an altimeter setting of 30.00 inches of mercury.

Witnesses reported the weather as clear skies and calm wind in the vicinity of the accident site around the time of the accident.

Wreckage and impact information

Witnesses to the accident marked the location where it impacted water as 33 degrees 24.6 minutes north latitude and 117 degrees 40.9 minutes west longitude. Recovery of the wreckage took place on November 22, 2005. The airplane remained intact via its primary structure and/or control cables. The lower side of the fuselage and engine sustained significant impact damage from the bottom side up and aft. The wings were cut from the fuselage to facilitate transport. The airplane was then taken to Aircraft Recovery Services in Palmdale, California, where it was examined on December 8, 2005, by the NTSB investigator-in-charge, two FAA inspectors from the Long Beach Flight Standards District Office (FSDO), an investigator from Cessna Aircraft Company, and an investigator from Teledyne Continental Motors.

The engine remained attached to the firewall, but the left-side engine mounts were fractured and separated. The right-side engine mounts were at