ACCIDENT RECOVERY


logged 6.6 hours as pilot in command during training and positioning flights. On Jul. 20 and 21, he logged 5.0 hours as SIC.


The Flight The dip site was only about a quar- ter mile from the section of the fire the crew had been assigned to work, enabling them to make numerous drops in 1.5 hours of flight time. At about 16:42 local time, a local res-


ident recorded a 38-second video clip of the helicopter establishing a 200-ft. hover over the river with the empty bucket swinging close to the water’s surface. It abruptly climbed about 125 ft. in 8 to 9 seconds while maintaining a relatively steady heading, then yawed to the left. After turning about 180 degrees, the aircraft pitched down, with the left yaw accel- erating until the helicopter crashed into the riverbank and the water. USFS firefighters on the scene saw


the accident and rescued the pilots. They were rushed to nearby hospitals but subsequently died of their injuries. Both deaths were attributed to “mul- tiple blunt-force injuries”; toxicology tests were negative.


The Investigation The final accident report from the US National Transportation Safety Board (NTSB) describes the organization’s examination of the wreckage in con- siderable detail. Item by item, they eliminated possible causes of mechan- ical failure throughout the flight-control system. Various fractures of control rods


were consistent with impact damage, while the associated bell cranks “moved


62 POWER UP JUN 2025


freely and were not seized.” All four integrated lower control


actuators remained in their normal locations, and the mechanical con- nections between their outputs and the first-stage mixing unit were intact. Both mixing units remained installed, and the control rods connecting them were intact except for the left yaw/ right roll rod, which had fractured in overload. The pressure-side expansion plugs


had been blown out of the aft swiveling upper boost actuators, but this was attributed to ground impact forces.


CH-47D, investigators found that if an iPad was put between the copilot’s left pedal and the airframe next to the heel slide support assembly, operation of the pilot’s left pedal caused the iPad to fall farther and become jammed between the copilot’s left pedal and the heel slide support assembly. Application of the pilot’s right pedal


The sudden downward pitch may have resulted from the copilot accidentally bumping the cyclic as he leaned forward to remove the iPad.


One puzzling anomaly provided a


clue, however. The pilot’s antitorque pedals were present but had discon- nected from their respective pedal position-adjustment plates, so that moving the pedals did not move the corresponding jackshafts. The right pedal position lever “had moved beyond its limit and was pointed left.” The copilot’s pedals remained attached to their position-adjustment plates, and the right pedal was adjusted to the “3,” or middle, position, consistent with the copilot’s height. The left pedal, however, was in the “5,” or full-forward, position. During the recovery of the wreckage,


the crew’s company-issued Apple iPad was found in the river. Three distinct gouges had been cut into one of the long sides of the device, and the case was bent from the back toward the screen. Using an identically configured


squeezed the iPad between the pedal and the support assembly; a sharp vertical metal piece on the bottom of that assembly aligned with the gouges in the recovered iPad. Right pedal input by the pilot “forced the iPad to apply more pressure to the copilot’s pedal adjustment lever.” With their restraints fastened, neither pilot would have been able to reach it. A Boeing simula-


tion study found that


although only 50% pedal input would be needed for the initial 180-degree left turn, full left pedal would be required to produce the yaw angle seen in the last three seconds before the crash. These findings led investigators to


conclude that while the flight crew set up for the dip, the “unsecured iPad” fell under the copilot’s left pedal and got jammed between the pedal and the airframe, preventing the pedals from returning to neutral. The sudden downward pitch may


have resulted from the copilot acci- dentally bumping the cyclic as he leaned forward to try to remove the iPad. The pilot probably reduced thrust in an attempt to slow the helicopter’s rotation, which allowed the helicopter to continue descending, and his efforts to help free the iPad by applying addi- tional pedal pressure allowed it to slip farther out of reach while accelerating


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