The number and composition of the flight crew shall not be less than those specified in the flight operations manual or aircraft operating manual and flight manual. Flight crew members may be increased or replaced when necessitated by considerations related to the type of aircraft used, the type of operation involved and the duration of flight between points where flight crews are changed.Flight Crew shall operate aircraft in accordance with the procedures, standards and limitations prescribed in aircraft operating manuals and flight manuals without infringement, unless when there is a proper cause necessitating a deviation.It is not allowed to have contradictory procedures appear from flight operations manual and aircraft operating manuals in paragraph 1.An operator shall ensure that the technique and the ability of the flight crew to execute emergency procedures are checked in such a way as to demonstrate the flight crew’s competence to the standards established by the operator and CAA.The checks set out shall be performed by check airman, 12 months after the flight crew has passed the check or the re-qualification check, and at least once within any 12 months from the date, which except the flight crew check or the re-qualification check.The check procedures as set out in Article 173 shall apply to the flight crew who are engaged in the commercial chartered flight operations and the pilot-in-command (PIC) who is engaged in the general aviation operations. However, the free balloon flights acting as pilot-in-command (PIC) shall not apply the previous check procedures.For the qualification of the check airman, refer to Attachment 19.ATTACHMENT 19 Check Airman Qualifications.odt