NTSB Factual Report

On April 23, 2001, at 1430 mountain standard time, a Bell 206-L3 single engine helicopter, N215M, was substantially damaged during a forced landing following a reported loss of engine power east of Willcox, Arizona. The commercial helicopter pilot and two crewmembers were not injured. The helicopter was operated by Critical Air Medicine, Inc., of San Diego, California, as a positioning flight under the provisions of 14 CFR Part 91. The flight had originated from Tucson International Airport, Tucson, Arizona, about 1400, and was scheduled to terminate at the Northern Cochise Community Hospital in Willcox. Visual meteorological conditions prevailed at the time of the accident, and a company visual flight rules flight plan had been filed.

In his accident report to the Safety Board, the pilot reported he added 40 gallons of fuel to the helicopter prior to departing Tucson, providing 450 pounds of fuel. Once the helicopter was approximately 13 miles northwest of Willcox airport, at an elevation of 500 feet agl, one of the flight nurses on board spotted a herd of antelope. The pilot turned the helicopter to the right, and as he leveled the helicopter and reduced power to slow down, "the engine out audio with corresponding engine out light came on."

The pilot noticed the rotor rpm dropping and looked at the engine turbine outlet temperature gauge to verify that the engine had lost power. He added that he could no longer hear the engine power. The pilot lowered the collective at 500 feet agl, and entered an autorotation. He noticed the rotor rpm was in the low 90's at the time of autorotation entry.

The pilot selected a landing area and informed the cabin crew that this was for real and to brace themselves. As the helicopter decelerated, he rolled the throttle to the off position. When he realized that he was going to impact a tree, he pulled up on collective to cushion the landing. The tail boom was separated from the helicopter during the landing sequence and the aircraft was tilted to the right side. The flight nurse yelled "rotor brake," and the pilot pulled the brake and stopped the rotor blade rotation. He then turned the fuel valve and battery off, pulled the fuel boost pump circuit breakers, and exited the helicopter.

The helicopter came to rest in flat desert terrain covered with scrub brush. Photographs taken at the accident site revealed open areas void of trees surrounding the landing spot.

A post accident inspection revealed that the skids were spread, the windscreen was broken, and the tail boom was severed into several sections. Both main rotor blades showed evidence of structural separation that began about 3 feet from the blade grips and extended outboard to the blade tips.

The helicopter was transported to the operator's facility where it was examined by the Safety Board investigator, and representatives from the helicopter and engine manufacturers. No preimpact anomalies were noted with the flight control system, main rotor transmission, and tail rotor system.

The aircraft's main fuel bladder had been defueled for transport. A functional test on the fuel pumps was conducted. The left and right fuel boost pump circuit breakers and all nonessential circuit breakers were opened. Electrical power was applied to the aircraft and the individual fuel boost pump circuit breakers were pushed in. Fuel was observed being supplied to the output of the airframe fuel filter. Both fuel boost pumps appeared to operate properly. The fuel lines running from the injector pumps aft through the in-line fuel filters were disconnected aft of the fuel filters. A collection pan for the fuel was connected to the fuel line, and the individual fuel boost pump circuit breakers were pushed in. The left and right injector and in-line filters appeared to operate normally. The airframe fuel filter was removed and examined and a nominal amount of debris was noted.

The Rolls-Royce Allison 250-C30P engine remained secured to the airframe mounts and displayed no external damage. The N1 section rotated freely when turned and was smooth and continuous to the starter generator. The N2 section was also rotated and was found to be free and smooth and was continuous to the aircraft main transmission. The presence of fuel was noted throughout the fuel supply system. All of the pneumatic and fuel supply system "B" nuts were checked and found to be at least finger tight. The engine was removed and transported to Air Services International in Scottsdale, Arizona, for an operational evaluation on a test stand.

Prior to the operational test run, a pneumatic system pressure check was conducted with no discrepancies noted. The engine oil filter and accessory gearbox chip detectors were also checked with no discrepancies noted. The engine was placed on the test stand and operated through several decelerations and accelerations with no anomalies noted. The engine's measured horsepower output was above new engine specifications at all test points with the exception of the takeoff power specification, which was only 1 horsepower below new specifications.

Review of the helicopter's maintenance records revealed that the helicopter had accumulated a total of 3,596.2 hours of flight time, and had undergone its last 100-hour inspection on March 8, 2001 at a helicopter total time of 3,524.1 hours. The helicopter's last annual inspection took place on November 9, 2000, at a helicopter total time of 3,324.3 hours. The engine had accumulated a total of 9,922.6 hours at the time of the accident. The turbine powered helicopter was not equipped with an engine auto reignition system.

The weather in Tucson (which was approximately 42 miles west-southwest of the accident site) was reported as clear with a surface temperature of 91 degrees Fahrenheit.

The pilot reported having accumulated a total of 4,980 hours of rotorcraft time, of which "2,000+" hours were accumulated in the same make and model as the accident helicopter. Review of Bell Helicopter Customer Training Academy Records revealed that the pilot underwent Bell 206L ground and flight training between November 29, 1999, and December 2, 1999. The 3.5 hours of flight training included emergency procedures that encompassed autorotation maneuvers.

NTSB Probable Cause

A loss of engine power due to the likely unporting of the fuel tank pickups as the helicopter was maneuvered to look at animals on the ground. Also causal was the pilot's misjudged touchdown point during an autorotational approach, which resulted in the in-flight impact with a tree.