The sanction of maintenance performed by unauthorized personnel without a certificate is:

The appropriate sanction for maintenance performed by unauthorized personnel without a certificate typically reflects the severity of breaching safety regulations and maintenance standards within engineering practices. A 30 to 45-day suspension is considered a reasonable length for this type of infraction, allowing for the individual or organization involved to reassess their compliance and rectify any gaps in certification.

This sanction serves as both a punishment and a deterrent, emphasizing the importance of adhering to proper certification protocols to ensure safety and effectiveness within the maintenance process. A shorter suspension period is often seen as sufficient for first-time offenders or less severe lapses in compliance, allowing them to return to their duties without long-term impacts on their career.

Longer suspension periods, as suggested by the other options, indicate more serious infractions or repeat offenses, which may not align with the context provided in the question, specifically regarding maintenance carried out by unauthorized personnel. In this case, a 30 to 45-day suspension appropriately balances the need for accountability with the opportunity for individuals to correct their actions and prevent future violations.