What is the correct repair for elongated bolt holes in a spar?

The correct repair for elongated bolt holes in a spar is to splice or replace the spar. This is because elongated bolt holes can compromise the structural integrity of the spar, which is a critical component in aircraft. Simply using a metal sleeve or filling the hole with epoxy does not restore the original strength and load-bearing capability of the spar.

A splice or replacement involves reinforcing or replacing the damaged section of the spar to ensure that it can adequately handle the loads experienced during flight. This is particularly important since the spar supports the wings and resists various forces, including lift, torsion, and bending moments. A proper repair of elongated bolt holes aims to restore the strength and safety of the aircraft, which is best accomplished through splicing or replacing the affected spar section.