Command Presence

By Richard N. Aarons
Source: Business & Commercial Aviation

After everyone was on board, the foreman closed the right passenger door and ensured that it was locked and secured. He then went forward to the right front cockpit window area, looked at the pilot who had his shoulder harness and seatbelt on, and motioned to him that the right passenger door was secured and the helicopter was ready for departure. The foreman watched the helicopter lift off, ascend to about 100 to 150 ft., make a 180-deg. turn to the north and begin forward flight heading northwest.

Phoenix terminal radar approach control first picked up the helicopter about 11 mi. south of the Whispering Pines Ranch at 1443:30. The aircraft was flying south toward SDL at a Mode C reported altitude of 7,500 ft. MSL and remained at that altitude until 1451:16, when it initiated a gradual descent that lasted until 1457:41. The helicopter was then at 6,000 ft. MSL. From this point, the helicopter initially climbed and then began a gradual descent with slight altitude, heading and airspeed fluctuations until 1503:27, when it reached 4,400 ft. MSL.

Radar data then depicted the helicopter make a rapid (5 sec.) climb from 4,400 ft. to 4,700 ft. followed by a rapid descent to 3,800 ft. MSL within the next 5 sec. The last radar return was recorded at 1503:37.

At the same time, several ground witnesses looked skyward when they heard a series of “pops” or “bangs.” They saw parts flying from the helicopter and watched as it spiraled into the ground.

The Investigation

Investigators from the NTSB, FAA, American Eurocopter and Turbomeca USA began operations the next morning. On Feb. 18, they were joined by representatives of the German Federal Bureau of Aircraft Accident Investigation (BFU) and Eurocopter Deutschland.

The linear debris path — consisting primarily of pieces of yellow main rotor blade and the left horizontal endplate — extended north from the main wreckage about 2,000 ft. All major aircraft components were accounted for near the wreckage or along the flightpath. There was no evidence of an inflight fire.

Impact forces and the post-crash fire destroyed the cockpit and cabin areas. The cockpit floor structure exhibited accordion compression in the aft direction. The twist grip throttles were both found past the neutral detent and in the high range. The anti-torque pedals were found in the near-neutral position. All flight controls were accounted for, and all flight control tube fractures appeared angular and consistent with overload. Those flight control components not damaged by impact forces were found attached and secured. The airspeed indicator had frozen at 103 kt., the rotor rpm gauge indicated 95%, the engine No. 1 gauge indicated 92%, and the engine No. 2 gauge indicated 90%.

The first identified piece of debris along the flightpath leading to the wreckage site was a piece of ribbon from the helicopter's left vertical endplate. An area of main rotor blade debris that included foam, honeycomb and paint chips was then identified extending from the initial point of the debris field south for about 1,050 ft. A large piece of the yellow main rotor blade was located about 750 ft. north of the main wreckage site. A fragment of the helicopter's tail-rotor driveshaft flex coupling was found about 695 ft. north of the wreckage. A lower piece of the left vertical fin was located about 450 ft. north of the main wreckage.

A further survey of the area revealed that a piece of the yellow blade tip was found about 400 ft. northwest of the main wreckage, with myriad small fragmented pieces of the helicopter observed between the blade tip and the wreckage site. The main rotor blades and hub were located about 25 ft. north of the primary wreckage site. The tail boom fenestron was lying on its right side at the main wreckage site and oriented in a north-to-south direction. Its ring frame exhibited heat damage and the fracture surfaces were consistent with overload.

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