NTSB Factual Report

HISTORY OF FLIGHT

On May 18, 1998, at 1351 central daylight time (cdt), a Bell 206L-1, N41BL, operated by a commercial pilot, while maneuvering over a residential area, departed controlled flight, impacting into a garage in Arlington Heights, Illinois. Visual meteorological conditions prevailed at the time of the accident. The business flight was being conducted under 14 CFR Part 91. No flight plan was on file. The helicopter was destroyed and the pilot and three passengers on board were fatally injured. The flight originated at Waukegan, Illinois, at 1248 cdt.

The helicopter had been chartered to carry a professional photographer and two staff members of the Chicago Futabakai School on a local flight over the Arlington Heights area, for the purpose of photographing the Futabakai School from the air. The owner said that the helicopter took off from in front of his company's hangar, on the Waukegan Municipal Airport, Waukegan, Illinois.

At 1302 cdt, the pilot contacted the Palwaukee Air Traffic Control Tower (ATCT), Wheeling, Illinois, and reported being 6 miles northwest of the Palwaukee Airport at 1,500 feet msl. The pilot requested to operate north and south of the Arlington Race Track in Arlington Heights. The Palwaukee ATCT issued the current altimeter setting and instructed the pilot to report when reaching the site.

At 1320 cdt, the pilot reported 3 miles west of the airport and below 1,500 feet msl.

At 1334 cdt, the pilot reported to Palwaukee ATCT that he was proceeding south and requested to talk to Chicago O'Hare ATCT. The frequency change was approved.

At 1337 cdt, the pilot contacted O'Hare ATCT and requested clearance into the Class B airspace. The pilot advised the tower that he would operate at or below 1,000 feet. Clearance was given, and the pilot was instructed to advise when the helicopter was on station.

At 1339 cdt, the pilot reported on station.

At 1344:07 cdt, the Chicago Terminal Radar Approach Control (TRACON) facility, at Elgin, Illinois, identified the helicopter's VFR beacon code, approximately 4.37 miles northwest of Chicago O'Hare International Airport. The helicopter was at an altitude of 500 feet above ground level (agl), on a 197-degree heading, and a ground speed of 70 knots.

At 1346:07 cdt, Chicago TRACON observed the helicopter turn to a 323-degree heading, at 300 feet agl and a ground speed of 70 knots. The helicopter was 5.24 miles northwest of Chicago O'Hare Airport.

At 1347 cdt, the pilot reported to the O'Hare ATCT that the helicopter was clear of the Class B airspace. The tower terminated radar services and approved a frequency change.

At 1347:26 cdt, the helicopter turned northeast on a 025-degree heading. The helicopter's altitude was approximately 600 feet agl, and its ground speed was 80 knots.

At 1348:49 cdt, the helicopter initiated a turn to a heading of 256-degrees. The helicopter's altitude at this time was approximately 500 feet agl, and its ground speed was 70 knots.

The last radar position that Chicago TRACON plotted on the helicopter was at 1350:17 cdt. The helicopter was 6.10 miles northwest of Chicago O'Hare Airport, heading 234-degrees, at 400 feet agl, and a ground speed of 60 knots.

A witness observed the helicopter from his 14th floor, west- facing apartment, located approximately 1/3 mile east-northeast of the accident site. The witness said that the helicopter flew over his apartment building within 100 feet. He watched the helicopter travel on a southwesterly heading away from the building in a level attitude. The witness estimated the helicopter to be approximately 350 feet above the ground. The witness observed the helicopter begin a slow banked turn to the left toward a southerly heading. The helicopter banked through 30 degrees up to 90 degrees of bank angle. The witness said the helicopter then pitched down and descended in a 70 to 80 degree nose-down pitch angle. The witness lost sight of the helicopter when it descended below the tree tops. The witness said that when the helicopter went over his building, he did not see any smoke trailing the helicopter. He also said that the helicopter noises sounded normal.

Another witness observed the helicopter from his 15th floor, west-facing apartment in the same building. The witness said that as the helicopter was going to the west, it was getting closer to the tree tops. The witness observed the helicopter turn south. The witness said that the helicopter "banked real hard [to the] south, so that the [main rotor] blades were perpendicular to the ground. The helicopter went straight down in a dive, nose first." The witness said that he was looking down on the helicopter from his vantage point, and estimated that the helicopter was only 15 feet above the tree tops when it dove in.

A third witness observed the helicopter from his second floor east-facing office, 1/4 mile west of the accident site. The witness said he saw the helicopter heading south very slowly. The helicopter then banked up on it's left side. The witness said that from his vantage point, he could see the bottom of the helicopter and make out both skids. The witness said that he lost sight of the helicopter behind some trees. The witness stated that he saw the helicopter "struggling in the wind."

At 1351 cdt, the Chicago Northwest Central Dispatch System received a 9-1-1 call that a helicopter had crashed into a residence at 311 South Fernandez Street, Arlington Heights, Illinois.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with ratings for rotorcraft-helicopter, instrument helicopter, and private privledges for single-engine land airplane. The pilot also held an instructor rating in helicopters. According to company records, the pilot had 5,300 total flight hours, 5,250 in helicopters, and 2,000 hours in Bell 206-series helicopters.

The pilot successfully completed an annual recurrent helicopter training course at the Bell Helicopter Customer Training Academy, Fort Worth, Texas, on February 3, 1998. During the course, the pilot received two flights in a Bell 206L-1, totalling 2.8 hours.

The pilot successfully completed an FAA Airman Competency/ Proficiency flight check on April 22, 1998. The flight was conducted in an Agusta 109A helicopter. The FAA inspector who conducted the flight check cited no discrepancies.

AIRCRAFT INFORMATION

The helicopter was one of two Bell 206 models owned and operated by Rotors-In-Motion, Corporation, of Waukegan, Illinois. The helicopter was used primarily for business purposes.

The helicopter had previously undergone an annual inspection, which included the entire airframe, 200 hour engine inspection, tail rotor, and driveshaft, on February 18, 1998.

WRECKAGE AND IMPACT INFORMATION

The NTSB on scene investigation began on May 18, 1998, at 1440 cdt.

The accident site was located in a residence at 311 South Fernandez Street, Arlington Heights, Illinois. The helicopter was found resting inverted in the southwest corner of the house at a 25-degree angle from horizontal, with the ground. The wreckage was confined predominantly to the garage of the house, the immediate driveway coming out of the garage, and a side yard southwest of the garage.

A witness mark, 22 feet long and 3 feet at its widest point, was observed beginning at the center of the roof, and running west- southwest to west, and ending at the roof apex over the front door porch. The roof tiles and wood framing along the witness mark were peeled up and back, in a southerly direction.

An 8 foot diameter hole was observed in the front portion of the garage roof. The helicopter's main wreckage rested beneath the remaining roof within the confines of the garage. Debris from the garage door and roof structure, pieces from the helicopter's cabin, and the left skid fanned southwestward from the garage in an 80-degree arc. The helicopter's left side litter door was broken out at the hinges and rested on the driveway, 10 feet from the garage. The left skid was located 40 feet from the garage on a 220-degree heading.

The main wreckage consisted of the entire fuselage, both skid cross-members, the engine and transmission, the tailboom, the horizontal stabilizer, the vertical fin, tail rotor, and tail skid. The main rotor was also located in the garage, but was separated from the helicopter at the base of the mast. The helicopter's right skid was found vertically embedded in the trunk of an automobile on the south side of the garage. The aft 3 feet of the skid penetrated upward through the collapsed roof.

The forward section of the helicopter including the nose structure, battery compartment, cockpit area, and passenger area aft to the bulkhead prior to the baggage compartment, was crushed inward and aft. The helicopter's nose and instrument panel were crushed aft and broken. The left and right windshields were broken out and shattered. The left and right crew doors were broken out at the door frame posts. The right side crew [pilot's] door was crushed inward and bent aft along the bottom. The top of the door frame was twisted inward and broken. The plexiglass window was broken out. The left side crew door was crushed inward. The upper plexiglass window was cracked and split laterally. The bottom sliding window was broken out. The cockpit floor was broken aft and bent upward behind the pilot's seat and behind the left side passenger seats. Both sets of control pedals were broken aft. The left pedal of the left set of control pedals was broken aft. The forward skid cross tube was crushed upward and aft through the bottom of the helicopter, into the front passenger compartment.

The ceiling of the passenger compartment was bent upward and aft, and split longitudinally in several places outboard either side of the transmission. The right passenger cargo door was broken out at the hinges. The plexiglass window in the right passenger cargo door was broken out and shattered. The window frame was bent aft and inward. The left passenger cargo door and litter door remained attached at the hinge-latches. Both doors were broken outward from the fuselage frame and bent aft. An 8- inch piece of plexiglass was broken out of the upper left passenger door window. The floor of the passenger compartment was broken laterally in two places. The front passenger floor section was broken aft of the crew compartment at fuselage station 73.00, and near the center of the compartment, just forward of fuselage station 122.90. This section was bent upward approximately 30-degrees from waterline 30.50. Passenger seats in this area were crushed upward and bent forward. The second floor section was broken at the aft cabin bulkhead, station 155.18. The aft skid cross tube was crushed upward and aft into the floor of the helicopter's intermediate section at a penetration angle of 47-degrees from waterline 20.

The transmission was intact and rotated freely. Push-pull tubes and control rods to the flight control system were examined in the field for continuity from the cyclic to the swashplate, and aft to the tail rotor. Flight control components examined displayed numerous fractures characteristic of overload failures.

The helicopter's intermediate section, containing the engine, cowling, firewalls, fuel tanks, and baggage compartment was predominately intact. The forward part of the cowling [forward faring and transmission faring], aft to station 150.00, was separated from the engine and broken into several pieces. The aft part of the cowling was bent and twisted outward, and showed areas of charring and soot. Several pieces of wood and roof tile were found embedded in this area. Some of the wood pieces were charred. The hydraulic reservoir and three hydraulic flight control boost actuators were broken out.

The engine was intact and was pushed inward. The top and right sides of the engine showed evidence of charring. The driveshaft was bent upward 65-degrees just forward of the freewheeling unit.

The upper portion of the intermediate compartment, beneath the engine, from waterline 73.586, was buckled outward and bent aft. The forward and aft firewalls were bent rearward approximately 25-degrees from the vertical plane. The bladder fuel tanks were torn open and shredded. The smell of jet fuel was prevalent. The baggage compartment door was separated at the hingeline.

The tailboom was buckled inward and bent 23-degrees to the left of centerline, and 18-degrees down, approximately 16 and 1/2 inches aft of boom station 31.855. The top of the vertical fin rested on the apex of the roof over the front door porch. No damage was observed to the tailboom, aft of boom station 31.855. There was no damage observed to the horizontal stabilizer, the vertical fin, or the tail skid. The tail rotor was intact and remained attached to the tail rotor gearbox. One tail rotor blade showed no damage. The other tail rotor blade was bent slightly inboard approximately 18 inches outboard of the output shaft. Examination of the tail rotor gearbox and output shaft revealed no damage. On removal of the tail rotor driveshaft cover, a torsional break in the 5th tail rotor driveshaft segment was observed, 16 and 1/2 inches inboard of the tail rotor gearbox.

The helicopter's main rotor was broken off at the mast, 34 inches inboard of the trunion. The mast fracture displayed torsional failure signatures. One blade (hence referred to as main rotor blade number two) was twisted upward and broken aft, 38 inches outboard of the blade bolt. Both blades (main rotor blade number one, attached to the rotor head and mast, and main rotor blade number two) were found resting parallel, next to each other, inverted, along the trunk and roof of an automobile in the north side of the garage. Main rotor blade number two rested north of blade number one, which was north of the helicopter's fuselage. Main rotor blade number two was bent upward at the fracture, twisted downward along the trailing edge, and displayed chordwise scratches and tar smears across the top of the blade.

Main rotor blade number one remained attached to the main rotor head at the blade bolt. The blade was bent upward and twisted forward approximately 30-degrees, beginning 17 inches outboard of the blade bolt. Beginning 50 inches outboard of the blade bolt, the blade was split longitudinally, outward to the blade tip. A 63 inch long, 8 inch wide aft section of the blade was bent upward approximately 90-degrees from the rotational plane. The blade section was also twisted inward 90-degrees. The leading edge of main rotor blade number one, from the point where the blade split, was bent and buckled outward to the blade tip. The final four inches of the blade at the tip showed chordwise scratches and tar smears.

A 38 inch long and 8 inch wide, piece of the trailing edge of main rotor blade number two was found in the attic of the house. It was bent upward, twisted aft, and displayed chordwise scratches and tar smears across the top of the blade.

Field examination of the engine controls and other helicopter systems revealed no anomalies. The engine and hydraulic flight control boost actuators were retained for further examination.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy of the pilot was conducted by the Cook County, Illinois, Medical Examiner on May 19, 1998, in Chicago, Illinois.

The results of FAA toxicology testing of specimens from the pilot revealed the following volatile concentrations: 0.007 (ug/ml, ug/g) Chlorpheniramine was detected in urine. Dextromethorphan was detected in urine. Dextrorphan was detected in urine. Dextrorphan was detected in blood. Nordextrorphan was detected in urine.

The Physician's Desk Reference for Non-Prescription Drugs states that chlorpheniramine is a sedating antihistamine found in many over-the-counter cold and flu medications. Chlorpheniramine taken in consistent dosages may cause drowsiness. Medications which contain chlorpheniramine will have a warning on the label stating, "Use caution when driving a motor vehicle or operating machinery." Dextromethorphan i

NTSB Probable Cause

Loss of helicopter control for unknown reasons.