Describe an acceptable repair method for elongated bolt holes found in a wooden wing spar.

• A. Remove the section containing the elongated hole(s) and splice in a new section
• B. Fill with epoxy and drill new holes
• C. Use a backing plate and longer bolts
• D. Ignore and continue use

Answer: (A)

When a wooden wing spar has elongated bolt holes, the strength and load path are compromised where the material around the holes has been weakened. The proper approach is to restore the spar by removing the damaged section and splicing in a new, solid section. This returns the bolt holes to fresh, intact wood with the correct geometry, reestablishes the original cross-section, and preserves the correct grain continuity so the load is carried as designed.

Drilling new holes or filling the holes with epoxy doesn’t restore the removed material or the proper load-carrying capacity of the spar; it leaves weakened regions and potential stress concentrations that can lead to fatigue or failure. Using a backing plate and longer bolts also doesn’t address the weakened area and can alter load paths or introduce new failure modes. Ignoring the damage is unsafe.

So, replacing the compromised region with a splice maintains structural integrity by re-establishing proper dimensions, fastener alignment, and material strength.