Which repair methods are generally acceptable for damaged threads on aircraft?

The acceptance of both running a die over damaged threads and retaping a thread in a block as repair methods stems from their effectiveness in restoring the function of threaded connections in aircraft.

When a die is run over a damaged thread, it can effectively clean and reshape the thread profile, allowing for a more secure fit of fasteners. This method is particularly useful when the damage is minor, such as when there are a few damaged crests or minor burrs that can be removed without altering the overall integrity of the thread.

Similarly, retaping a thread in a block is a standard practice for repairing damaged threads, especially in cases where precision is critical. This involves using a tap to create new threads within the original structure, which can restore the fit and strength of the connection. This method is especially effective in blocks where the integrity of the threaded hole is essential for maintaining structural stability.

Both methods are widely accepted and practiced within aerospace maintenance, provided they are executed correctly and in line with the manufacturer's specifications. This dual approach allows for flexibility depending on the extent of the damage, ensuring that repairs can be tailored to meet the specific needs of the aerospace component involved.