Final answer:
An FAA Commercial Pilot with helicopter ratings can add an Airplane Single Engine category and class rating by meeting specific FAA requirements.
Step-by-step explanation:
An FAA Commercial Pilot certificate allows a pilot to operate aircraft for compensation or hire. The Rotorcraft-Helicopter and Instrument Helicopter ratings indicate that the pilot is qualified to fly helicopters and helicopters by reference to instruments, respectively.
To add an Airplane Single Engine category and class rating, the alien would need to meet specific requirements set by the FAA. These requirements generally include a minimum number of flight hours, passing a written knowledge test, and passing a practical flight test. Once the alien meets these requirements, they can apply to add the rating to their existing certificate.
Adding the Airplane Single Engine rating opens up opportunities for the pilot to fly single-engine airplanes, which may be required for certain jobs or aviation activities.