What form is required to be filed by the operator of an aircraft within 10 days after an accident?

The correct form to be filed by the operator of an aircraft within 10 days after an accident is the NTSB Form 6120.1/2. This form is critical for reporting incidents to the National Transportation Safety Board (NTSB) and is mandated by federal regulations. The requirement to file within 10 days ensures timely reporting of accidents or certain incidents involving aircraft, which helps maintain safety oversight and allows for investigations aimed at improving aviation safety.

This form serves to collect essential data about the accident, including details about the aircraft, the circumstances, and any injuries involved. The significance of this form lies in its role in the NTSB's mission to investigate transportation accidents and promote safety improvements across the aviation sector.

Other forms listed in the question serve different purposes. For instance, FAA Form 337 is used for major repairs and alterations to aircraft, while Form 2703 pertains to specific operational and maintenance requirements for aircraft certification, and the Incident Report Form 423 may not directly apply to the reporting of accidents as specified by the NTSB guidelines. Understanding the specific purpose and requirement of the NTSB Form 6120.1/2 is crucial for compliance with aviation safety regulations.