Maintenance-Caused Cracks Ground Hercs

Gemini Sparkle

Key Takeaways:

  • The Air Force has grounded 116 C-130H aircraft (over 20 percent of its fleet) after determining that cracks in their propellers were caused by inscriptions made during inspection documentation.
  • These cracks originated from digits incised into the metal using an electric arc pen, a process that weakened the propeller surface. This problematic engraving method was stopped six months ago.
  • Some C-130Hs have since been returned to service, and the Air Force is continuing to study how the cracks spread, aiming to incrementally restore the remaining aircraft while prioritizing crew safety.
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The Air Force has grounded 116 C-130Hs, more than 20 percent of the fleet, after it was determined that inscriptions scratched in the propellers documenting inspections for cracks actually caused cracks. “The process used to engrave serial numbers on the propellers likely contributed to cracks that are being found on the C-130Hs,” Maj. Beau Downey, an Air Force spokesperson, told Defense One. “That process, which involved an electric arc pen to incise digits into the surface of the metal, was stopped about six months ago and will not be used going forward.”

Some of the aircraft have been returned to service but the Air Force won’t say how many. The cracks and aircraft groundings came to light in October, but the cause wasn’t released until this week. Downey said the Air Force is studying how the cracks spread from the inscriptions and is working on getting the Hercs back on the line. “This will be an incremental process based on operational priority and our focus remains the safety of our crews.”

Russ Niles

Russ Niles is Editor-in-Chief of AVweb. He has been a pilot for 30 years and joined AVweb 22 years ago. He and his wife Marni live in southern British Columbia where they also operate a small winery.
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