Which document is commonly used to authorize field approvals for minor alterations or repairs?

Which document is commonly used to authorize field approvals for minor alterations or repairs?

• A. Supplemental Type Certificate
• B. Airworthiness Certificate
• C. FAA Form 337
• D. Airworthiness Directive

Answer: (C)

Field approvals for alterations or repairs are documented with FAA Form 337. This form provides an official record of work done in the field and the FAA-approved data supporting the change, capturing what was changed, how it was justified, and who performed and inspected the work. Because it is the standardized document used to authorize field changes, it is the best fit for recording minor alterations or repairs that aren’t covered by existing type certificate data. The other options serve different roles: a Supplemental Type Certificate is for major, design-level changes that modify the type design; an Airworthiness Certificate simply certifies the aircraft is airworthy; and an Airworthiness Directive is a mandatory safety directive affecting many aircraft and is not used to authorize a specific field modification.

Field approvals for alterations or repairs are documented with FAA Form 337. This form provides an official record of work done in the field and the FAA-approved data supporting the change, capturing what was changed, how it was justified, and who performed and inspected the work. Because it is the standardized document used to authorize field changes, it is the best fit for recording minor alterations or repairs that aren’t covered by existing type certificate data. The other options serve different roles: a Supplemental Type Certificate is for major, design-level changes that modify the type design; an Airworthiness Certificate simply certifies the aircraft is airworthy; and an Airworthiness Directive is a mandatory safety directive affecting many aircraft and is not used to authorize a specific field modification.