FTW98FA068

On takeoff from an automobile accident site, with the patient on board, the air ambulance flight made a climbing right turn and flew into power lines. Witness marks on the helicopter provided evidence the helicopter struck the transmission line from below and impacted the ground in an inverted attitude below and to the west of the lines. Light conditions were a dark night with emergency response, construction, and emergency response vehicle lights illuminating the landing site area. The existence of the power lines was unknown to the fire rescue on-scene commander and the light conditions prevented the pilot from seeing anything outside the lighted area. The unmarked power lines were 622 feet apart and oriented northeast/southwest. The southern tower was 106 feet high and the northern tower 83.5 feet high. The towers and lines did not meet obstruction-marking criteria and were not marked. In addition, they were not depicted on sectional or topographic maps. Company policy, promulgated through documents and training, provided landing zone departure procedures which instructed the pilot to climb straight ahead in a near vertical climb to a minimum of 300 feet agl before turning. The horizontal distance from the helicopter's takeoff position to the power line was approximately 630 feet based on global positioning system (GPS) measurement.

History of flight

On December 14, 1997, at 2200 mountain standard time, a Bell 407 helicopter, N771AL, operated by Air Methods Corporation as an air ambulance, impacted power lines then terrain during initial climb following takeoff from an accident scene in Littleton, Colorado. The helicopter was destroyed and the commercial pilot, two flight nurses, and the patient received fatal injuries. Visual meteorological conditions prevailed and a company flight plan was filed for this medical evacuation flight operating under Title 14 CFR Part 135. The flight departed a hospital in Aurora, Colorado, approximately 20 minutes prior to the accident.

According to witnesses, the flight arrived from the northeast and circled the site clockwise before landing heading south on U. S. Highway 85. After picking up the patient, who was one of the victims in a multiple injury/fatality automobile accident, the flight was on initial climb following takeoff, and in a right turn, when it struck power lines. The lines were to the west of the takeoff point across the South Platte River and located on a riverside golf course bounded on the west by condominiums.

Measurements, information from Public Service Company, and the witness marks on the helicopter provided evidence the helicopter struck the transmission line from below and impacted the ground in an inverted attitude below and to the west of the lines.

Personnel information

The pilot was a former U. S. Army helicopter pilot and reportedly had extensive rotary wing experience. He held commercial pilot certificate number 1987204, issued January 17, 1979, with a helicopter rating. He held an instrument rating in helicopters.

According to the company, he had 4,118 hours of flight experience, all of which was in helicopters, and had 122 hours of flight experience in the Bell 407. He had 583 hours of night flying experience and 333 hours of simulated instrument experience. He did not have any actual instrument flight time recorded.

Federal Aviation Administration (FAA) records provided information the pilot held a first class medical certificate issued June 3, 1997, with the restriction that he wear corrective lenses while exercising the privileges of the certificate.

According to company records, the pilot was hired on June 6, 1996, and completed initial flight training, including a 14 CFR Part 135 flight check on July 1, 1996. During initial training he received 11 hours of flight instruction in the Bell 206 L-3 which is certified for both VFR and IFR operation.

He completed Bell Helicopter factory training on the Bell 407 on February 3, 1997. The training included 2.2 hours of flight training and was VFR only.

He completed recurrent ground training on February 18, 1997, and recurrent flight training in the Bell 407 on May 4, 1997. His flight check in the Bell 407 was completed on May 5, 1997. He then had another recurrent training session in the Bell 407 on December 5, 1997. The training was VFR only because the Bell 407 was certificated for VFR only operations.

Flight time duty time records for the pilot are attached for the months of October, November, and December, 1997. They provide information that the pilot was on duty from 0900 to 1900 the day prior to the accident and flew 1.1 hours during daylight on that day. He was off all company duty for 23 hours and reported for duty the day of the accident at 2100. The accident flight was his first flight after reporting for duty.

Aircraft information

The aircraft was a Bell 407 helicopter, serial number 53068, manufactured in 1996. At the time of the accident, it had accumulated 464 total hours and had flown 130 hours since the last inspection. It was certificated in the normal category for single pilot operation and was powered by an Allison 250-C47B turbo-shaft engine rated at 630 shaft horsepower. The engine serial number was CAE0847092. It was manufactured in 1996 and had accumulated 474 total hours.

The helicopter was equipped for emergency medical service and, in addition to the pilot, was equipped to be occupied by one patient and two flight nurses. The medical kit installation was done in accordance with Supplemental Type Certificate (STC) number SR00275DE, dated April 16, 1997. Copies of the technical data related to the STC are available from the Federal Aviation Administration, Denver Aircraft Certification Office.

It was equipped with a Pointer 3000 emergency locator transmitter, which was in the armed position, and activated during the impact sequence. It did not aid in locating the accident.

Meteorological information

The weather reporting facility nearest the accident site was Centennial Airport located approximately 10 miles to the east. The 2245 observation was clear skies, 30 miles visibility, temperature 39 degrees, wind 130 degrees at 7 knots, and an altimeter setting of 30.07 Hg.

According to the company, the pilot was given the following weather information prior to dispatch: Scattered clouds at 2,500 feet above ground level, 10 miles visibility, wind from 210 degrees at 18 knots and an altimeter of 30.01 Hg. No temperature information was given.

According to personal observations by the Investigator-In-Charge, and witness information, general conditions in the area of the accident was dark night conditions and clear skies. Localized visibility was limited to the area around the accident site/landing zone lighted by highway lights, construction lights, emergency service lights, and emergency response vehicle lights. Objects outside the lighted area, including the power line and support towers, were not visible from the takeoff area.

Attached is illumination information provided by the National Weather Service. The information indicates that sunset occurred at 1644 and the end of twilight was 1714. The altitude of the moon was 47.9 degrees above the horizon on a magnetic bearing of 95.4 degrees and the percent of moon illumination was 98%.

Communications

Recorded communications between the fire department on-scene commander and the helicopter pilot are attached. They provide evidence the on-scene commander briefed the helicopter pilot on known obstructions and the helicopter pilot, in turn, briefed the on-scene commander on the planned approach. No mention was made of the power lines to the west of the river, and according to available information, their presence was unknown at the time.

Wreckage and impact information

The helicopter came to rest on its left side on a northerly orientation. The fuselage was intact and deformed to the left and down from the top. The tail boom was severed just aft of the cabin area and just forward of the horizontal stabilizer. The tail rotor blades remained attached to the tail rotor drive shaft. Witness marks on the aft separation provided paint transfer marks which matched the paint on the main rotor blades. The forward separation point was ragged and the fracture area was crushed down and aft.

The pilot's seat remained attached and occupiable space was present. The cyclic and collective remained attached in normal fashion and the anti torque pedals were displaced aft. The left side of the cockpit area was crushed inward and contained a portion of the liter rack which remained attached at its mounting points. The medical equipment in the cabin area remained attached; however, the seats were displaced up and to the rear.

Cockpit documentation was as follows:

* Artificial horizon 30 degrees left wing down on horizon * Standby artificial horizon 45 degrees right wing down, 5 degrees nose down * Horizontal Situation Indicator (HSI) heading 210 degrees, heading bug 000 degrees course 090 degrees * Bearing Distance Heading Indicator (BDHI) course selector 005 degrees, "to" in window, needles centered * Radio Magnetic Indicator heading 235 degrees needle on 255 degrees * Nr/Nf 0 * Airspeed 0 Needl