NTSB Identification: WPR10FA371
Nonscheduled 14 CFR Part 91: General Aviation
Accident occurred Wednesday, July 28, 2010 in Tucson, AZ
Aircraft: AMERICAN EUROCOPTER LLC AS350B3, registration: N509AM
Injuries: 3 Fatal.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On July 28, 2010, at 1342 mountain standard time, an American Eurocopter AS350B3, N509AM, rapidly descended and collided with terrain in an urban area of Tucson, Arizona. The helicopter was operated by Air Methods Corporation, as LifeNet 12, on a repositioning flight, under the provisions of Title 14 Code of Federal Regulations Part 91. The commercial pilot and two medical flight crew were killed. The helicopter was substantially damaged, and consumed by a post impact fire. Visual meteorological conditions prevailed, and a company flight plan had been filed. The flight originated at Marana Regional Airport, Tucson, at 1332.

Witnesses reported seeing the helicopter flying steadily in a southeast direction when it started to descend rapidly and enter a left-hand turn. Witnesses also stated that the helicopter made some unusual ‘whump, whump’ sounds, and rapid intermittent popping sounds, which was followed by unusual quietness as the helicopter descended. As the helicopter turned and got closer to the ground its flight trajectory became increasingly vertical. It impacted the ground in a level attitude and burst into flames.

Initial radar data indicated that the helicopter was on a steady southeast course, at 131 knots ground speed, and 900 feet above ground level (agl). The last 8 seconds of radar data indicated that the helicopter descended 600 feet. The last radar return was at 1341:32, approximately 140 feet agl, and 0.25 miles from the accident site. The pilot did not transmit a radio distress call.