History of Flight
On October 15, 2008, at 2358 central daylight time, a Bell 222 helicopter, N992AA, operated by Air Angels Inc. and piloted by a commercial pilot, was destroyed when it impacted a radio station tower and the ground in Aurora, Illinois. The tower stood 734 feet above ground level. A post crash fire ensued. The emergency medical services (EMS) transport flight was conducted under 14 Code of Federal Regulations Part 135, and was en route from the Valley West Hospital Heliport (0LL7), Sandwich, Illinois, to the Children’s Memorial Hospital Heliport (40IS), Chicago, Illinois, when the accident occurred. Night visual meteorological conditions prevailed in the area of the accident site. All four occupants, including the pilot, a flight paramedic, a flight nurse, and the 14 month old patient, were fatally injured. The flight originated about 10 minutes prior to the accident.
Reach dispatch (Air Angels flights were dispatched by Reach Air Medical Services in Santa Rosa, California) was notified of the need for EMS transport at 2112 and opened a case record at that time. At 2113, the flight was accepted by Air Angels; however, the flight did not depart the Air Angels base in Bolingbrook, Illinois until 2254. The flight had been delayed until a receiving hospital could be identified. At 2311, N992AA arrived at 0LL7. At 2338, the pilot made a flight following call to Reach dispatch as required in Reach/Air Angels protocol. The flight following call included the helicopter's takeoff weight of 7,635 pounds, the helicopter's center of gravity of 251.7 inches, center of gravity range of 247.65 to 256.0 inches, the planned initial heading of 080 degrees, distance of 38 miles, estimated time en route of 18 minutes, 4 people on board, 1.5 hours of fuel on board, and Children's Memorial Hospital as the destination. The flight following call was made prior to takeoff from 0LL7.
At 2355, the pilot checked in with the DuPage Airport (DPA) air traffic control tower (ATCT) and reported his position as "over Aurora," and that the helicopter was at 1,400 feet above mean sea level (msl). Radar data showed that at the time of the radio call to DPA ATCT, the helicopter was about 12 nautical miles (nm) northeast of the departure heliport. Radar data showed that the helicopter continued on a 072-degree magnetic course. The radar data showed the helicopter on a steady course at a constant altitude of 1,300 feet MSL. The radar track ended at 2358:25 and the location of the last radar return coincided with the location of a radio station antenna tower.
Personnel Information
The pilot, age 69, held a commercial pilot certificate with rotorcraft-helicopter and instrument helicopter ratings. The certificate also listed private pilot privileges for single-engine land airplanes. The pilot's most recent second class medical certificate was issued in January 2008 and stated that the pilot must wear corrective lenses for near and distant vision.
The pilot was hired by Air Angels in July 2006. A review of the pilot's Air Angels training records indicated that he had accumulated 3,564.7 flight hours total time, including 3,182.7 hours in helicopters and 382 hours in fixed wing aircraft. While employed by Air Angels he had accumulated 282.7 hours in the Bell 222, including approximately 50 hours and 23 hours in the preceding 90 and 30 days respectively. During the month of October the pilot had flown 5.7 hours at night and made 20 night landings in Bell 222 helicopters.
Training records showed that the pilot completed new hire and initial training in July 2006 and his most recent recurrent training was accomplished in August 2008. The pilot's most recent annual line check (FAR Part 135.299) was completed on September 25, 2008.
Aircraft Information
The helicopter was a Bell 222, serial number 47062. It was configured for medical transport of a single patient on a gurney. Air Angels acquired the helicopter in February 1999. The crew consisted of a single pilot, flight nurse, and paramedic. A review of the helicopter's maintenance records revealed that it had 5,302.6 hours total time as of October 14, 2008. The helicopter had two Honeywell (Lycoming) LTS-101-650C engines. The number 1 engine had 5,694.0 hours total time, and the number 2 engine had 3,717.1 hours total time. The most recent phase inspection was performed on September 24, 2008, at 5,270.9 hours total airframe time.
During the flight-following radio call to Reach Dispatch, the pilot reported the weight of the helicopter as 7,635 pounds, the center of gravity (CG) at 251.7 inches and a CG range of 247.65 to 256.0 inches. The Bell 222 Flight Manual, limitations section listed the maximum gross weight for takeoff and landing as 7,850 pounds. Referring to the Bell 222 Flight Manual gross weight center of gravity chart, the CG that the pilot reported was within the normal operating limits as defined by that chart.
Communications
At 2338:25, the pilot contacted Reach dispatch for his pre-takeoff flight following call. The call included the following information: Initial heading 080 degrees; distance 38 miles; estimated time en route 18 minutes; destination-Children's Memorial Hospital; 4 people onboard; 1.5 hours fuel onboard.
The helicopter was being operated in night visual flight rules (VFR) conditions and was outside of the DuPage Airport (DPA) class D airspace. However, at 2355:21, the pilot, identifying the flight as Lifeguard Angel 1, contacted DPA ATCT. The controller acknowledged the transmission. At 2355:28, the pilot stated, "Ah sir we are just over Aurora en route to Children's Hospital ah downtown Chicago at about 1,400 feet." At 2355:36, the controller responded, "Lifeguard Angel 1 cleared through the delta current altimeter 3014." The pilot acknowledged the altimeter setting at 2355:42. At 2358:26, an unidentified transmission similar to "ahhhhhhhh" was heard on the frequency. There were no further contacts with the aircraft.
Wreckage and Impact Information
The helicopter impacted the ground in a forest preserve. The terrain at the location was flat with prairie grass that stood about 6 feet high. The helicopter had impacted the 734-foot tall radio station tower on its west side about 50 feet from the top of the tower. The tower structure had buckling of the vertical structural members. The tower was supported by guy-wires that extended from the tower structure at an outward angle toward the ground. The uppermost guy-wire on the west side of the tower was severed and found lying on the ground. The tower was equipped with a high intensity strobe lighting system with the one set of strobes installed at the top of the tower and another set installed about 2/3 of the height of the tower. The conduit that contained the electrical wiring that supplied power to the strobe light system was severed about 50 feet from the top of the tower and the strobe lighting system was not operational after the accident. The distance and direction from the radio station tower to the main wreckage site were about 1,250 feet and 070 degrees respectively.
The helicopter was severely fragmented and sustained damage due to a post impact fire. The vertical tail and portions of the tail rotor and gearbox were found near the initial impact point of the main wreckage. Both engines, the helicopter transmission, and the majority of the fuselage were found farther along the wreckage path. The helicopter's main rotor mast had separated at the point where the shaft entered the transmission. The separated portion of the rotor mast, along with the rotor head and rotor blades was found about 450 feet and 210 degrees from the main wreckage. The rotor head remained intact with the large portions of both rotor blades still attached. The main rotor blades exhibited damage along their entire span. The tips of both blades along with their respective counterweights had separated from the inboard portions of the blades. The blades exhibited delamination of the composite skins and fracture of the honeycomb core material aft of the metal leading edge. Pieces of honeycomb core material, composite skin and the counterweight tips from the blades were recovered from an apartment complex located adjacent to the location of the tower.
Examination of the helicopter remains after removal from the accident site revealed no defects that could be determined to have existed prior to the impact.