What is the primary purpose of FAA Form 337?

The primary purpose of FAA Form 337 is to record major repairs and alterations made to an aircraft. This form is essential for documenting any significant changes to the airframe, engine, or other critical aircraft components. It serves as an official record that can be referenced by regulatory authorities, safety inspectors, and future maintenance personnel.

By maintaining accurate records of major repairs and alterations, owners and operators ensure compliance with Federal Aviation Regulations and help maintain the safety and airworthiness of the aircraft. This documentation also supports the overall accountability of maintenance work performed, which is vital for tracing the history of modifications and repairs over the lifespan of an aircraft. The information recorded on this form includes details about the nature of the work performed, the date of completion, and the signature of the person approving the work, ensuring that proper standards have been met.