On February 19, 2006, approximately 0200 central standard time, a twin-engine Bell 222B helicopter, N306CH, registered to and operated by Central Helicopters Inc., of Houston, Texas, sank into ocean waters following a loss of control while on approach to an ocean vessel in the Gulf of Mexico. The airline transport pilot and commercial rated copilot were not injured. Dark night visual meteorological conditions prevailed, and a company flight plan was filed for the 14 Code of Federal Regulations Part 91 position flight. The flight originated from the William P. Hobby Airport near Houston, Texas, at 0104, en route to the ship Shaula Star, which at the time of the accident was navigating in the Gulf of Mexico, approximately 85 miles south of Galveston, Texas. The 11,308-hour airline transport pilot reported on the Pilot/Operator Accident Report Form (NTSB Form 6120.1/2), that he and the copilot had the brightly lighted ship within sight and was preparing to land. The pilot stated that there was a 25-knot wind and haze. He had the autopilot engaged and turned on the landing light, set the parking brake, and extended the landing gear. Additionally, the pilot reported that the copilot was preparing to assist the ship's crew once on deck. The pilot stated that he disengaged the autopilot system and pressed the SAS/ATT (Stability Augmentation System/Attitude Retention System) button to change from attitude mode to SAS mode, when he looked up just in time to see the water. The helicopter sank in approximately 200 feet of water and was not recovered. The pilot added that there was no mechanical problem with the helicopter prior to the accident. A review of the helicopter's Blue Sky flight tracking program revealed the helicopter was en route to the ship at an altitude of about 500 feet. At 08:02 UTC, the last recording, the helicopter was at an altitude of 640 feet, at a speed of 89 knots. In the NTSB Form 6120.1/2 under the section; Recommendation (How This Accident Could Have Been Prevented): The pilot stated that better cockpit crew resource management and "standardization of crew coordination procedures has become paramount importance due to this very avoidable accident". Additionally, the pilot stated that the helicopter's radio altimeter has a light annunciator, but no audio warning. He added, that the company is seeking to install audio warning signals that activate with separate and distinct tones at 150 and 50 feet. The weather recorded near the departure time by the automated weather observing system at HOU; was wind at 030 degrees at 13 knots, 9 miles visibility, few clouds at 600 feet, overcast sky at 800 feet, temperature 39 degrees Fahrenheit, dew point 35 degrees Fahrenheit, and an altimeter setting of 30.36 inches of Mercury. The pilot's forecast weather en route was for 10 miles visibility in haze, clouds at 800 feet, and an overcast ceiling of 800 variable to 1,200 feet.