MIA97FA070

Witnesses observed the helicopter flying from north to south and collide with a 253-foot agl radio tower at about the 235-foot level. The main rotor blades partially separated and the helicopter descended uncontrolled to ground impact. The radio tower was depicted on aviation charts and was marked by an operational strobe light. The pilot had many years of operational experience in the area. Postmortem examination of the pilot showed he suffered from moderate chronic pulmonary emphysema and that he had a carbon monoxide level in the blood of about 26%. The pilot was reported to smoke about 1 pack of cigarettes daily. The 3 passengers did not have carbon monoxide in their blood. The source of the carbon monoxide level in the pilot could not be determined.

History of flight

On January 23, 1997, about 0751 eastern standard time, a Bell 206-B3, N2047R, registered to Mitsui and Company USA, Inc., collided with a radio tower while in cruise flight near Fort Lauderdale, Florida, while on a Title 14 CFR Part 91 worker transport flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter was destroyed and the commercial-rated pilot and three passengers were fatally injured. The flight originated from a boat ramp parking lot, 4 miles from the crash site, about 0748.

The operator of the helicopter stated the company holds an Air Taxi Certificate issued by the FAA under Title 14 CFR Part 135. They were under contract to the South Florida Water Management District to provide helicopter services, and conducted these flights in accordance with Title 14 CFR Part 91. The pilot was taking workers to the Everglades to perform ground eradication of trees.

A supervisor for the workers who were passengers on the helicopter stated the helicopter arrived at the boat ramp parking lot around 0730. On arrival the pilot parked the helicopter facing south and left the engine running. He then exited the helicopter and unloaded reserve fuel containers, placing them in an area to the northwest of the parked helicopter. The pilot then joined two supervisors who were standing about 35-50 yards in front of the helicopter and to the left front of an airboat that had a running engine. During this time the pilot smoked one cigarette. After returning to the helicopter, the passengers were loaded and the flight departed toward the south. This was about 15-20 minutes after the flight arrived.

Witnesses observed the helicopter flying from the north to the south on the west side of highway 27. They stated the helicopter appeared to be flying at normal cruise speed and sounded normal. A short time later they heard, and one witness saw the helicopter collide with a radio tower. They then observed the helicopter descending nose first and the tail section separating from the helicopter. They also observed debris from the main rotor system falling and that the top of the radio tower was damaged.

Personnel information

Information on the pilot is contained in the First Pilot Information section of this report and in attachments to this report.

Aircraft information

Information on the aircraft is contained in the Aircraft Information section of this report and in attachments to this report.

Meteorological information

Visual meteorological conditions prevailed at the time of the accident. Sun and moon calculations showed that at the time of the accident the sun was at an altitude of 7.9 degrees on a bearing of 121.1 degrees and the moon was at an altitude of -12.3 degrees on a bearing of 298.7 degrees. Additional meteorological information is contained in the Weather Information section of this report and in attachments to this report.

Wreckage and impact information

The aircraft crashed in a grass area adjacent to a parking lot on the west side of Highway 27. The crash site is across Highway 27 from the Sawgrass Recreation Area. Examination of the crash site showed that about the top 20 feet of a 253 foot agl radio tower was separated and lying about 100 feet to the south of the tower base. Several guy wires had been broken. The bending on the remaining top portion of the tower was toward the southwest. Debris from the main rotor blades of the helicopter was found near the base of the tower and along a line leading to the main wreckage of the helicopter, which was about 300 feet to the south of the tower. One portion of the main rotor blade that was found at the base of the tower had damage consistent with impact with the tower structure.

Examination of the helicopter main wreckage showed that all components of the helicopter which are necessary for flight were located on or around the main wreckage except for the outboard portions of the main rotor blades, which were located to the north toward the radio tower. The helicopter had impacted nose first and came to rest on the left side, on a heading of 165 degrees. The tailboom was separated and lying near the aft end of the fuselage. The complete skid system had separated from the fuselage and was lying forward of the fuselage. Continuity of the flight control systems was confirmed. All separation points in the flight control systems were typical of overstress separation.

The engine to transmission main driveshaft was partially separated at the main transmission end due to impact force. The main transmission was rotated and continuity of all drive outputs was confirmed. Continuity of the main rotor head and the tailrotor driveshaft was confirmed. All separation points were consistent with overstress separation.

Examination of the engine showed the compressor section was crushed and had severe rotational damage. Continuity of the compressor section, burner section, and turbine section was confirmed and all damage was consistent with impact damage. There was no evidence of precrash mechanical failure or malfunction of the engine assembly. Examination or testing of all engine controls showed no evidence of precrash mechanical failure or malfunction of the controls.

Portions of windshield debris found at the crash site showed the windshield was in good condition with no scratches or crazing.

Medical and pathological information

Postmortem examination of the pilot was performed by Dr. Eroston A. Price, Associate Medical Examiner, Broward County, Florida. The cause of death was attributed to multiple blunt trauma injuries. Findings during the postmortem exam were arteriosclerotic cardiovascular disease mild and chronic pulmonary emphysema moderate.

Postmortem toxicology studies on specimens obtained from the pilot were performed by Gene deTuscan, Toxicologist, Broward County Medical Examiner's Office, Dr. Dennis Canfield, FAA Toxicology Laboratory, Oklahoma City, Oklahoma, and Dr. Gary Kunsman, Armed Forces Institute of Pathology, Washington, D.C. The Broward County Medical Examiner tests were positive for 13 percent carbon monoxide and negative for ethanol alcohol and drugs. The FAA Toxicology Laboratory tests were positive for 26 percent carbon monoxide and negative for cyanide, ethanol alcohol, and drugs. The Armed Forces Institute of Pathology tests were positive for 28 percent carbon monoxide using the FAA Laboratory specimens and positive for 6 percent carbon monoxide using the Broward Medical Examiner specimen. No other tests were performed by this laboratory.

Postmortem examination of the three passengers was performed by Dr. Eroston Price, Broward Medical Examiner's Office. The cause of death in each case was determined to be due to multiple blunt trauma injuries.

Toxicology studies on specimens obtained from the three passengers were performed by Gene deTuscan, Broward Medical Examiners Office. The tests on all three passengers were negative for carbon monoxide and drugs. The passenger seated in seat 2A was positive for .02 g percent ethanol alcohol. The other two passengers were negative for ethanol alcohol.

For additional medical and pathological information see Supplements K to this report and the toxicology test reports attached to this report.

Fire

There was no evidence of a precrash or postcrash fire.

Tests and research

The radio tower that N2047R collide with was owned and operated by the U. S. Army Corps of Engineers. The tower was located at position 26 degrees 11 minutes north latitude and 80 degrees 27 minutes west longitude. The tower had a height of 253 feet above ground level and 271 feet above sea level. According to an FAA inspector the tower was equipped with a medium intensity strobe light that operated full time and therefore was not required to be painted for visibility. The tower is depicted on aviation sectional navigation