Which of the following is NOT a category of airworthiness certificate?

The correct response to the question regarding airworthiness certificate categories is that the "Commercial Category" is not a recognized category of airworthiness certificate.

In aviation, airworthiness certificates serve as formal documentation that an aircraft complies with safety and operational standards set by aviation authorities. The recognized categories include:

• The Standard Category pertains to aircraft designed primarily for general aviation use and that meet specific safety standards.

• The Restricted Category is designated for experimental or limited-purpose aircraft that do not conform to the full requirements of a standard category but are deemed safe for limited operations.

• The Special Category typically includes certificates for aircraft that require specific operational limitations or have been modified from their original design, which may not meet the full standards for a standard category.

The absence of a "Commercial Category" reflects that the regulations do not classify aircraft based solely on commercial usage; instead, they categorize them based on operational capabilities and compliance with established safety regulations.