Which combination of certificates allows an airman to perform as a flight engineer?

The correct combination of certificates that allows an airman to perform as a flight engineer includes a temporary flight engineer certificate and a second-class medical certificate.

To serve as a flight engineer, an individual must possess specific qualifications granted by aviation authorities. The temporary flight engineer certificate demonstrates that the pilot has met the necessary training and testing requirements for that role, effectively permitting the pilot to operate the systems and procedures vital for a flight engineer. A second-class medical certificate is a requirement for many piloting roles, ensuring the airman meets the necessary health standards to safely perform their duties.

The other options presented do not meet all the necessary requirements for performing as a flight engineer, making them insufficient for this specific role. Only the combination of a temporary flight engineer certificate, acknowledging the specialized training, along with the second-class medical certificate, fulfills the regulatory criteria.