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PatiencePatience

NTSB Accident No. ERA13FA186NTSB Accident No. ERA13FA186

Hurrying rarely improves results in any field. Most of us can recall having overlooked something in a rush, whether it’s the briefcase left on top of the car or the stove that may or may not have been turned off. In most circumstances, the harm that results is at least manageable. When the oversight involves an aircraft, it may prove catastrophic.

On the afternoon of April 3, 2013, a Robinson R44 took off from the Kendall-Tamiami Executive Airport outside Miami. A few minutes later, witnesses near the airport heard a loud noise and saw parts separate from the helicopter before the main rotor blades severed the tail boom. The fuselage rolled inverted and crashed into two palm trees before hitting the ground, igniting a fire that consumed most of the wreckage. The pilot and his passenger, an A&P mechanic who also held a pilot certificate, were both killed.

Examination of the wreckage showed that the lower end of one main rotor blade’s pitch-change link had apparently detached from the rotating swash plate. The bolt connecting the two is normally secured by a steel self-locking nut backed by a palnut—but none of the connecting hardware was found and its mounting hole showed no evidence of damage or deformation, suggesting that the bolt backed out rather than breaking.

The pilot owned the company that operated the helicopter. His girlfriend described it as a “one-man show” offering air tours, photo flights, and instruction. Since he was not a CFI, contract instructors provided the flight training. One was a county police sergeant who had worked with the owner from time to time in the two and a half years since he’d added a helicopter rating to his instructor certificate. He’d flown the accident helicopter on a photo flight on Feb. 24 during which it displayed no anomalies. However, the next 100-hour inspection revealed delamination of the main rotor blades, requiring them to be removed and shipped back to the Robinson factory.

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The blades were returned to Robinson by overnight delivery sometime between March 7 and March 13, but the replacements didn’t arrive until April 2—and when they did, the owner was upset to find that the factory had refurbished the spindles from the old blades rather than installing new ones. (His girlfriend attributed this to “miscommunication.”) Both the spindles and the blades themselves are subject to a 2,200-hour life limit, so the installation of used spindles meant that the blades would have to be removed some 760 hours earlier than would have been the case with a zero-time assembly. However, concern over revenue lost during the down time, which he estimated at $10,000 per month, convinced him to install the blades in order to get the helicopter back onto the flight line while he sorted things out with the company. A mechanic who had done other work for him in the past was engaged to supervise their installation, tracking, and adjustment.

On the afternoon of April 3, the sergeant brought a student to the hangar for a ground lesson. On the way in he stopped to talk to the mechanic as the owner shut down the helicopter after a test flight. One blade was tracking high, so the mechanic got a ladder and began adjusting the pitch change links. He also spoke briefly to the owner, who he thought seemed upset and preoccupied with getting the aircraft back into service. On another pass through the hangar he saw the mechanic reinstall the connecting hardware hand tight before climbing down and returning to his tool box, commenting on the way that they’d probably be there until 7:30 p.m. He wasn’t there to see whether the mechanic ever tightened the bolt to the required torque, but later saw him putting reflective tape on the bottom of the blade.

Blade tracking is done using a strobe light from inside the cabin. The A&P took the left seat and the pilot settled into the right. The sergeant saw the helicopter lift to a five-foot hover and make a series of pedal turns. After five or 10 minutes, they departed the airport to the south. Word of the crash came about eight minutes later.

While the mechanic didn’t seem to be in a hurry, his comment about working until 7:30 lends credence to the impression that the owner was anxious to wrap up the work that day. The missing hardware and lack of damage to that section of the swash plate suggests that somewhere in the course of their interactions, a small but utterly crucial step may have been overlooked.