PartWorks

What is aircraft hole repair?

Aircraft hole repair is the process of restoring structural fastener holes in airframe components that have been compromised by mis-drilling, fatigue damage, or corrosion. These holes anchor the rivets, bolts, and fasteners that hold an airframe together under cyclic flight loads. When a hole is damaged or out of tolerance, it reduces load-bearing integrity, accelerates fatigue crack initiation, and creates a structural failure risk that compounds with every flight cycle. Precision repair restores both the dimensional accuracy of the hole and, when performed correctly, the fatigue life of the

What are the methods used for aircraft hole repair?

Three methods are in common use. Oversized rivets are the legacy approach — the damaged hole is enlarged to accept a larger fastener, restoring mechanical function but leaving fatigue damage unaddressed. Bushing inserts are an intermediate solution — a precision sleeve restores original fastener geometry but does not improve fatigue life. Cold expansion is the current best practice for any repair where fatigue life is a performance requirement. It is the only method that actively improves the structural condition of the hole rather than simply restoring its dimensions.

How does cold expansion repair an aircraft hole?

Cold expansion repairs an aircraft hole in four steps. First, the damaged hole is inspected and measured to confirm it falls within the repair envelope — diameter, depth, and surrounding material condition are verified. Second, the appropriate expansion mandrel size is selected based on hole geometry and the target compressive stress level. Third, the mandrel is pulled through the hole under controlled force, plastically deforming the metal wall and introducing a uniform ring of compressive residual stress that suppresses fatigue crack growth. Fourth, process execution is validated — dimension

What is the difference between cold expansion and traditional aircraft hole repair?

Traditional hole repair methods — oversized rivets and bushing inserts — restore a hole to a serviceable condition. Cold expansion makes the hole better than it was before damage occurred. The key difference is compressive residual stress. When a mandrel cold-works a fastener hole, it plastically deforms the surrounding metal, leaving a ring of compressive stress that directly counteracts the tensile stresses generated by flight loads. Tensile stress drives fatigue crack growth; compressive stress suppresses it. The result is a repaired hole with a fatigue life three times or greater compared

How does PartWorks' RepAR system improve aircraft hole repair?

RepAR combines augmented reality guidance with real-time process validation to eliminate the two most common failure points in aircraft hole repair: technician error during the procedure and missing or incomplete process records after it. The system overlays step-by-step repair instructions directly into the technician's field of view, eliminating the need to reference paper manuals while working on the airframe. Simultaneously, RepAR captures dimensional measurements, mandrel selection data, and process execution results digitally, generating a complete validation record for every hole repair