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|Accident date||January 28, 2003|
|Aircraft type||Agusta A109C|
|Location||West Chicago, IL
Near 41.872223 N, -88.254444 W
HISTORY OF FLIGHT
On January 28, 2003, at 2053 central standard time (cst), an Agusta A109C helicopter, N109MX, piloted by an airline transport pilot (ATP), was destroyed during an in-flight collision with terrain about two nautical miles (nm) south of DuPage Airport (DPA), West Chicago, Illinois. Night marginal visual flight rules (MVFR) weather conditions prevailed at the time of the accident. The positioning flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot was fatally injured. The flight departed at 2051 and was maneuvering south of the airport at the time of the accident.
The helicopter was operated by Air Angels Incorporated, an on-demand air ambulance service. The operator is based at a heliplex located on the southeast perimeter of DPA. According to company personnel, the helicopter was returning from the DPA Flight Center after refueling with 56 gallons of Jet-A fuel.
The pilot of N109MX contacted the DuPage Control Tower at 2050:01 (hhmm:ss) and requested to "depart to the east if possible and head out to the south real quick and come back in on two left, and then land at the heliplex." At 2050:05, the tower controller told N109MX to "use caution departure uncontrolled, and ah, you gonna shoot an approach or just come in towards the numbers of two left?" The pilot of N109MX replied "I'm (unintelligible) status check a couple pieces of equipment we got then shoot two left, takeoff and land at the heliplex." The tower controller responded "that's no problem, Angel One you proceed as requested."
At 2051:10, a driver of a snow removal vehicle operating on runway 2L asked the tower controller if he needed to be off the runway to allow N109MX to land. The tower controller responded, "I was just debating that, um I would say you would be no problem out there, he's just gonna check some instruments and then break off probably at ah the approach lights and go to the heliplex." At 2051:15, the tower controller asked N109MX if he needed the snow removal vehicle to be off the runway during his approach. The accident pilot replied "That's negative." There were no additional communications with N109MX.
According to the tower controller, N109MX departed southbound from the Flight Center and while enroute the pilot "requested to continue south to check equipment." The tower controller stated he "observed a flash of light" to the south of the airport and that he was subsequently unable to communicate with the helicopter.
The helicopter operator initially reported that the marker beacon system was inoperative on the accident helicopter. However, at a later date the operator stated that the inoperable marker beacon system was not on the accident helicopter, but on another aircraft at their heliplex. A review of the daily usage logs for the accident helicopter failed to reveal any discrepancies with the maker beacon system within 30 days of the accident. The pilot who flew the helicopter prior to the accident flight did not report any malfunctions with the helicopter, and had successfully flown an instrument landing system (ILS) approach just prior to the accident pilot being dispatched with the helicopter.
Aircraft radar track data for the period before and after the reported accident time was obtained from the Chicago Terminal Radar Approach Control (TRACON) facility. The obtained data indicated a single aircraft transmitting a visual flight rules transponder beacon code (1200) maneuvering south of DPA around the time of the accident.
The first radar return was at 2051:17, with the helicopter positioned about 0.4 nm east of the DPA control tower at 800 feet pressure altitude or about 200 feet above ground level (agl). The helicopter traveled to the south about 1.7 nm before turning to the south-southwest around 2052:13. The final radar return was at 2052:31, with the helicopter positioned about 2.0 nm south of the control tower at 1,400 feet pressure altitude (~800 feet agl). The last radar return was about 425 feet east of the initial ground impact.
While traveling to the south, the helicopter climbed to 1,100 feet pressure altitude (~500 feet agl) while accelerating from 95 knots to about 125 knots airspeed. At 2052:00, the helicopter's climb rate began increasing from 500 feet/min to about 2,000 feet/minute over an 18 second period. During this 18 second period the helicopter decelerated from 125 to 100 knots airspeed. At 2052:22, the helicopter was positioned about 1.9 nm south of the control tower at 1,600 feet pressure altitude (~1,000 feet agl). Based on the last two radar returns, the helicopter descended approximately 200 feet that resulted in a 1,350 feet/min descent rate. Further examination of the data showed the helicopter decelerating from 85 to 35 knots airspeed during the descent.
DAMAGE TO AIRCRAFT
The helicopter was destroyed by impact forces and a subsequent explosion/fire.
According to Federal Aviation Administration (FAA) records, the pilot, age 52, held an ATP certificate with a rotorcraft/helicopter rating. The pilot also had commercial privileges for single and multi-engine land airplanes and instrument airplane operations. He was type-rated for the Bell 212, Eurocopter BK-117, and Sikorsky 58. The pilot also held a certified flight instructor certificate with rotorcraft/helicopter and instrument helicopter ratings. FAA records show the pilot's last medical examination was completed on April 2, 2002, when he was issued a second-class medical certificate with no limitations or restrictions.
The pilot began his flying career with the United States Army in October 1968 and remained on active duty until October 1984. Between December 1984 and July 1986, he provided instrument flight instruction for United States Army pilots while working for DWS Incorporated, Daleville, Alabama. The pilot was stationed in Yemen as the Chief of Standardization and Training for Bell Helicopter from September 1986 to April 1989. Beginning in May 1989 and continuing through January 1991, he was a pilot and company check-airman for Omniflight Helicopters, an air-ambulance operator based in Dallas, Texas. The pilot then took a position as a company check-airman for Petroleum Air Services, and was stationed in Egypt from February 1991 to August 1999. From February 2000 to August 2000 he was a pilot for Rocky Mountain Helicopters, an air-ambulance operator. The pilot was the Director of Training of Aris Helicopters Ltd., an air-ambulance operator, between August 2000 and September 2001. The pilot then joined Air Angels Incorporated on July 16, 2002.
According to company records, when hired the pilot had a total flight experience of 12,000 flight hours, of which 9,500 hours were in helicopters and 2,500 hours were in airplanes. The pilot reported having 11,200 hours as pilot-in-command (PIC). The pilot had accumulated 250 hours in actual instrument conditions, 310 hours in simulated instrument conditions, and 1,000 hours of night experience.
The pilot had flown 79.1 hours during the past year, 22.2 hours during the prior 90 days and 10.4 hours during the previous 30 days. The pilot had flown 1.9 hours during the 24 hours before the accident. The pilot's first flight in an Agusta A109C was on July 18, 2002, and he subsequently accumulated 56.3 hours in the helicopter. The pilot was approved for 14 CFR Part 135 operations after successfully passing a FAA Airman Competency/Proficiency Check on July 25, 2002.
The pilot worked 17 twelve-hour shifts during the previous 30 calendar days. The pilot's duty schedule comprised of 7 twelve-hour shifts, followed by 7 days off-duty. The accident occurred during the pilot's last shift for the seven-day work week. The pilot reported for duty on January 28, 2003, at 1900, after being off-duty for 12 hours. According to company personnel records, the pilot was working his final shift as an employee with Air Angels Incorporated when the accident occurred.
The accident helicopter was an Agusta A109C, serial number 7604. The accident helicopter was operated as a light utility emergency medical service (EMS) helicopter and was configured with an extended door conversion that increased the cabin interior volume. The extended crew and cabin doors were installed in accordance with supplemental type certificate number SH701NE, originally developed by the Keystone Helicopter Corporation, West Chester, Pennsylvania. The helicopter's maximum certified gross weight was listed as 2,720 kg (5,997 lbs).
The accident helicopter was issued a standard airworthiness certificate on September 23, 1998, after being imported from Germany. The helicopter was maintained under the provisions of a FAA approved inspection program. The last inspection, a 25 hour/30 day inspection, was performed on January 10, 2003, at 2,976.0 hours total time. Prior to the accident flight the aircraft had accumulated a total time of 2,994.3 hours.
The helicopter was powered by two 450 shaft-horsepower Allison 250-C20R/1 turbo-shaft engines. The left (number one) engine, serial number CAE295129, had accumulated a total time of 2,846.7 hours and 6,961 cycles. The right (number two) engine, serial number CAE295134, had accumulated at total time of 2,817.8 hours and 6,898 cycles.
The closest weather reporting station to the accident site was located at the departure airport, about 2.0 nm north of the accident site. The airport is equipped with an Automated Surface Observing System (ASOS). The following weather conditions were reported prior to and after the time of the accident:
At 1953: Wind 360 degrees true at 4 knots, visibility 3 statute miles (sm) with mist, few clouds at 2,400 feet agl, overcast ceiling at 7,000 feet agl, temperature -03 degrees Celsius, dew point -03 degrees Celsius, altimeter setting 30.02 inches-of-mercury, sea-level pressure 1017.7 millibars.
At 2053: Wind 340 degrees true at 8 knots, visibility 4 sm with mist, scattered clouds at 700 feet agl, broken ceiling at 1,400 feet agl, overcast ceiling at 7,000 feet agl, temperature -02 degrees Celsius, dew point -03 degrees Celsius, altimeter setting 30.06 inches-of-mercury, sea-level pressure 1019.0 millibars.
At 2104: Wind 350 degrees true at 6 knots, visibility 4 sm with mist, broken ceiling at 900 feet agl, overcast ceiling at 1,400 feet agl, temperature -02 degrees Celsius, dew point -03 degrees Celsius, altimeter setting 30.05 inches-of-mercury, ceiling variable between 500 and 1,200 feet agl.
Night conditions were prevailing with 15 percent of the moon's visible disk illuminated, according to data supplied by the U.S. Naval Observatory.
The pilot was communicating with the DuPage control tower at the time of the accident. A transcript of the voice communications is included with the docket material associated with this factual report.
The DuPage Airport (DPA) is located in West Chicago, Illinois. The airport has four asphalt runways: 2L/20R (7,570 feet by 100 feet), runway 2R/20L (5,100 feet by 100 feet), runway 10/28 (4,751 feet by 75 feet), and runway 15/33 (3,401 feet by 100 feet). The general airport elevation is listed as 758 feet mean sea level (msl).
The elevation of the runway 2L threshold is listed as 751.3 feet msl. Runway 2L is serviced by an instrument landing system (ILS) used for precision instrument approaches. The locator outer marker and middle marker are positioned 5.2 and 0.4 nm from the runway threshold, respectively. A medium intensity approach lighting system with runway alignment lights precedes the runway threshold.
The accident helicopter was not equipped, nor was it required to be equipped, with a cockpit voice recorder (CVR) or flight data recorder (FDR).
WRECKAGE AND IMPACT INFORMATION
The National Transportation Safety Board's on-scene investigation began on January 28, 2003.
A global positioning system (GPS) receiver was used to identify the position of the initial impact as 41-degrees 52.340-minutes north latitude, 88-degrees 15.26-minutes west longitude. The aircraft impacted a harvested cornfield located about two nm south of DPA.
The wreckage was distributed in a fan-shaped area that initiated from the initial impact point. The centerline of the debris field was situated between the initial impact point and the main wreckage. The main wreckage was positioned about 187 feet from the initial impact point on a 243 degree magnetic bearing. The main wreckage was located along a tree line and a barbed-wire fence that bordered the western edge of the field. The main wreckage consisted of the main transmission, main rotor mast and hub assembly, both engines, the cockpit, and a majority of the fuselage structural components. The main cabin and cockpit were damaged and fragmented.
The tail rotor, tail rotor gearbox, tailboom, and the upper vertical fin were found separated from each other, 20-25 feet from the initial impact point. The entire main landing gear assembly was found about 97 feet from the initial impact point. The EMS litter assembly was located about 152 feet from the initial impact point.
The main rotor system was destroyed. However, all portions of the main rotor system were accounted for at the accident site. Most portions of the fragmented rotor blade system were found on the north side of the debris centerline.
The wreckage was recovered and relocated to a nearby facility for reconstruction efforts, due to the extensive damage and overall distribution of the wreckage. The wreckage was first sorted by airframe location and then repositioned in a two-dimensional reconstruction. The two-dimensional reconstruction determined that all primary airframe structural components, flight control systems, rotor systems, transmissions, and powerplant components were present.
A majority of the recovered wreckage exhibited fire and heat damage on both internal and external surfaces. Flight control continuity could not be established due to the extensive damage to all components. The mixing lever assembly and the two lateral actuator magnetic brakes were found intact with fractured control rod-ends. Inspection of the recovered flight control components did not exhibit any evidence of pre-impact malfunction.
The tailboom assembly was found separated from the aft fuselage and all four structural longerons were sheared, consistent with overload. The lower tailboom surface was crushed upward along its entire length. The upper vertical fin was found separated from the tailboom. The lower vertical fin and stinger remained attached to the tailboom and were impacted up against the lower tailboom surface. The right and left elevators remained connected by their common torque tube, and elevator control continuity was confirmed throughout the tailboom assembly.
The tail rotor was found separated from its mast and gearbox. The tail rotor blade damage was consistent with rotational damage, including S-shape blade bending. The tail rotor gearbox was found separated from the tailboom, but remained attached to the upper portion of its tailboom structural support. The lower portion of the support remained attached to the tailboom and the fracture features were consistent with overload. The input pinion splines were not damaged and no abnormal wear signatures were noted. The tail rotor gearbox exhibited continuity when the output shaft was rotated by hand. The non-rotating levers, sleeves and linkages exhibited continuity when exercised by hand. The rotating components were fractured at the end lugs and the remaining portions remained connected to the tail rotor blade grips. The tail rotor servo actuator was removed for additional testing.
The aft tail rotor driveshaft remained attached to the tailboom. The driveshaft was displaced forward about three-inches. The Thomas drive coupling was bent to the left, exhibiting overtorque damage signatures. The aft adapter splines exhibited contact damage with the tail rotor gearbox input splines.
The main transmission was found with the main wreckage an