An investigation into a military plane crash that killed 16 people blames the accident on faulty work done at Robins Air Force Base.
The U.S. Marine Corps KC-130T crashed July 10, 2017 on farm land near Itta Bena, Mississippi. It was carrying 15 U.S. Marines and a Navy sailor when it suffered a catastrophic failure at 20,000 feet and crashed, scattering debris over a wide area.
A copy of the accident investigation report obtained by The Telegraph concludes that the crash was caused by a propeller blade that broke off. The blade, on the engine closest to the left side of the fuselage, slammed into the fuselage and set off a chain reaction that brought the plane down, according to the report.
Nothing the crew could have done would have prevented the crash, the report concludes.
The report states corrosion was found on the blade, and that a protective coating over the corrosion is proof it was there when the propeller was overhauled at Robins in 2011. The anodize coating is applied as part of the overhaul process. The corrosion should have been detected at that time and either corrected or the blade condemned, the report states. The corrosion led to a crack that caused the blade to break off.
“The lack of detection and removal of this corrosion is attributed to noncompliance with established publications and procedures within them,” the report concludes.
The plane has four engines with four propeller blades on each, or 16 blades in all. On 12 of those blades, corrosion was found that should have been detected and corrected during the overhaul, according to the report. The propeller work is done in the Warner Robins Air Logistics Complex, the maintenance area at Robins.
The investigation was conducted by the Fourth Marine Aircraft Wing.
The report makes 17 recommendations to prevent a similar occurrence, including changes in maintenance procedures and record keeping. Brig. Gen. John Kubinec, commander of the Warner Robins Air Logistics Complex, said those changes have been made. Robins halted propeller overhaul in September, 2017 and it remains halted. He expected it will restart early next year.
“When we first heard that work done here in 2011 may have contributed to the mishap, leadership and the (propeller) shop were devastated,” Kubinec said. “The first thing we did was take action to ensure that processes were in place that this wouldn’t happen again. That’s what our commitment has been since we first heard about it.”
It’s uncertain why the corrosion was missed, he said. Air Force regulations at the time required maintenance records to be kept for two years, so the records have been destroyed. One of the recommendations now being implemented is for records be digitized and kept indefinitely.
The lack of records means there’s no way to pinpoint what exactly was done to the blade and who did it. Even if that was known, Kubinec said it’s not certain the technician was at fault.
“It’s clear to us that we need to give our technicians better technologies, better techniques and procedures to be able to identify any kind of defects in these blades,” he said.
Also among changes that have been made as a result are better quality control, he said. The report recommends that a supervisor conduct quality control inspections on every step of the overhaul process.
The investigation stated that from 2011 until 2017, quality control checks were not done on every step on every blade.
Kubinec said he is confident the missed corrosion on the crashed plane was an isolated incident. After the crash, more than1,300 C-130 propeller blades were inspected and corrosion was found only on two, he said. That corrosion was minor and would be expected on planes that are in operation.
Also, Kubinec said he is certain no worker would have knowingly failed to correct corrosion that had been detected. He speculated that one possibility is the corrosion was detected and the blade set aside for repair, but by accident the propeller moved through the process without the corrosion work getting done. Part of the new procedures helps ensure that would not happen.
The accident marked the first time a plane crash has been blamed on work done at the base, according to the Robins public affairs office.
“Our workforce knows that the work they do directly impacts lives,” Kubinec said. “We are dedicated to that culture of compliance and quality and safety.”