Repair, Alteration, and Return to Service
Core concepts
A repair restores an item to an airworthy condition; an alteration changes its configuration or characteristics. Both must be accomplished using approved data: manufacturer structural repair manuals, approved engineering documents, or regulator-approved data. Major repairs and alterations typically require approval and may affect the type design, whereas minor ones may be handled under defined procedures by authorized personnel. Candidates must understand return to service as a formal act: the work is complete, approved data was used, required inspections and tests are done, and a properly authorized person signs the release. Know how form 1-type documents and dual releases work when work crosses organizations.
Traps in questions
A frequent trap is treating an unapproved field repair as acceptable because it is structurally sound. Soundness is not the test; approved data and authorization are. Another trap: assuming any licensed engineer can approve a major repair. Approval authority depends on the organization and the regulator. Questions may also blur repair and alteration; if the change affects weight, balance, performance, or structural capability, treat it as an alteration requiring assessment. Watch for release signatures made by persons outside the authorized scope.
Worked example / rule of thumb
Rule of thumb: No approved data, no repair. Worked example: a technician proposes reinforcing a cracked bracket with a doubler designed on site. Correct answer: this is a repair requiring approved data; a locally designed doubler needs engineering approval before installation. After installation, the required inspection and functional check must be completed and the release signed by authorized staff with the correct scope.