When is an operator of an aircraft involved in an incident required to submit a report to the NTSB?

The correct choice is that an operator is required to submit a report to the NTSB within a specified timeframe that is defined by regulations, rather than only when requested by the NTSB. Under the regulations, the operator must submit a report for certain types of incidents, including accidents or incidents that involve substantial damage or injury.

The timeframe for submission ensures timely reporting and facilitates the NTSB's investigation process. Depending on the nature of the incident, this timeframe can vary. For instance, accidents typically require notification within 24 hours, while other types of incidents requiring reporting may have different deadlines, such as 7 days for specific occurrences. Thus, simply stating that a report is only required if requested does not align with the requirements set forth by the NTSB for mandatory reporting in order to maintain safety and regulatory compliance in aviation operations.