Abstract: A seal-cover assembly for a structure including a first side and a second side opposing the first side. The seal-cover assembly includes a cap defining a recess, and an insert fixed to the cap within the recess to form a cover unit. The cover unit is configured to be secured to the first side of the structure. The seal-cover assembly includes a fastener configured to be disposed through the structure from the second side of the structure. The fastener is attached to the cover unit relative to the second side without accessing the first side of the structure. Additionally, an aircraft includes the structure and the seal-cover assembly as discussed above. Furthermore, a method of assembling the seal-cover assembly to the structure includes the cover unit secured to the first side of the structure such that an interior of the cover unit is inaccessible from the first side.

Abstract: Methods and structural gap filler for one up assembly of structures. Drilling debris generated between the first component and the second component during drilling of an injection hole are encapsulated by injecting a structural gap filler through the injection hole and between the first component and the second component.

Abstract: Fuel tanks and methods of manufacture are presented. A fuel tank in a wing of an aircraft comprises a composite skin, a composite spar, and a structural gap filler between a flange of the spar and a first surface of the skin, the structural gap filler having a compressive strength equivalent to or greater than a compressive strength of a joint between the composite spar and the composite skin.

Abstract: A seal-cover assembly for a structure including a first side and a second side opposing the first side. The seal-cover assembly includes a cap defining a recess, and an insert fixed to the cap within the recess to form a cover unit. The cover unit is configured to be secured to the first side of the structure. The seal-cover assembly includes a fastener configured to be disposed through the structure from the second side of the structure. The fastener is attached to the cover unit relative to the second side without accessing the first side of the structure. Additionally, an aircraft includes the structure and the seal-cover assembly as discussed above. Furthermore, a method of assembling the seal-cover assembly to the structure includes the cover unit secured to the first side of the structure such that an interior of the cover unit is inaccessible from the first side.

Abstract: Disclosed herein are methods and compositions for preparing a surface comprising thermoplastic or thermoset material to receive a polysulfide or polythioether sealant or coating, the method comprising applying to the surface an activating composition consisting of a tetraalkoxide of a Group 4 metal, a complex of an alkoxide of a Group 4 metal, or a combination thereof.