377 (1) have flown in heavier-than-air craft a total of 200 hours at least 75 of which were flown alone or as first pilot of a dualcontrol aircraft; or (2) have been in the air under training in lighter-than-air craft at least 150 hours. § 6024. Aviation designations: naval aviation observer Any officer of the naval service may be designated a naval aviation observer if he has successfully completed the course prescribed for naval aviation observers and has been in the air at least 100 hours. § 6025. Aviation designations: aviation pilot Any enlisted member of the naval service may be designated an aviation pilot if he has successfully completed the course prescribed for aviation pilots and— (1) has flown in heavier-than-air craft a total of 200 houra at least 75 of which were flown alone or as first pilot of a dualcontrol aircraft; or (2) has flown in lighter-than-air craft a total of 200 hours at least 150 of which were under training. § 6026. Supply Corps officers: bonds (a) Each officer in the Supply Corps, before entering upon the duties of his office, shall give a good and sufficient bond to the United States, approved by the Secretary of the Navy, to account for all public money and property that he receives. The bond shall be in an amount prescribed by the Secretary. The Secretary may waive the requirement of a bond for any officer who is not accountable for public funds or public property. (b) When required by the Secretary, an officer in the Supply Corps shall post a new bond with sufficient surety. (c) The promotion or appointment to a new office in the Supply Corps of an officer who is bonded under this section does not affect his existing bond. The bond remains in force and continues to cover the officer in his new office. §6027. Medical Department: composition The Medical Corps, the Dental Corps, the Medical Service Corps, the Nurse Corps, and the Hospital Corps are in the Medical Department of the Navy. § 6028. Medical Service Corps: composition The following sections, and such other sections as the Secretary of the Navy considers necessary, are in the Medical Service Corps: (1) Pharmacy, Supply, and Administration Section. (2) Medical Allied Sciences Section. (3) Optometry Section. §6029. Dental services: responsibilities of senior dental officer (a) The Secretary of the Navy shall prescribe regulations for dental services on ships and at shore stations. Such services shall be under the senior dental officer, who is responsible to the commanding officer of the ship or station for all professional, technical^ and administrative matters concerning dental services.