What must be completed before applying new LO coatings?

Before applying new low observable (LO) coatings, it is essential that the surface must be thoroughly cleaned. This step is crucial because any dirt, oil, or contaminants on the surface can prevent the coating from adhering properly, resulting in poor performance and potential failure of the coatings. A clean surface ensures that the new LO coatings can bond effectively, providing the protective and stealth characteristics needed for the aircraft.

In the context of applying coatings, contamination can lead to not only adhesion issues but also inconsistencies in the finish, which could affect the aircraft's radar cross-section and overall effectiveness. Proper cleaning typically involves removing any previous coatings, grease, dust, and other particles that could interfere with the new layer being applied.

This makes thorough surface cleaning the most important prerequisite for achieving a successful application of new LO coatings.