A certificated mechanic without an inspection authorization who signs on a GACA Form 8320-1/FAA Form 337 is certifying what?

When a certificated mechanic without an inspection authorization signs a GACA Form 8320-1 or FAA Form 337, they are certifying that the work performed on the aircraft was completed in accordance with the regulations set forth in 14 CFR part 43. This part provides the standards for maintenance, preventive maintenance, and alterations of aircraft. By signing the form, the mechanic essentially asserts that the work conducted meets these regulatory standards, ensuring that all necessary procedures were followed and documented properly.

The other options may imply safety or readiness, but they do not specifically relate to the regulatory compliance aspect defined in 14 CFR part 43. The signing of the form is a confirmation of adherence to these maintenance regulations rather than a broad statement about the overall condition or safety of the aircraft for flight.