Aircraft Flight Operation Regulations Article 173

An operator shall ensure that the pilot technique and the ability to execute emergency procedures are checked in such a way as to demonstrate the pilot’s competence to the standards established by the operator and CAA.A flight crew who holds a pilot license with several variants of the same type of airplane or different types of airplanes with similar characteristics may be given a combined similar aircraft type-rating check approved by CAA.For the operator who operates the flight under instrument flight rules, the checks set out in paragraph 1 herein shall be to ensure that its flight crew have the capabilities to operate instrument flight.The checks set out in paragraphs 1 and 2 herein shall be performed by check airman, between four to eight months after the date which flight crew has passed the proficiency check or the re-qualification check.Except the flight crew check or the re-qualification check, the proficiency checks set out shall at least twice within any 12 months. The interval of such two checks shall be between 4 months and 8 months. And, the content of the subsequent check shall not be identical with the previous check.