49 CFR § 1550.7 - Operations in aircraft of 12,500 pounds or more.
(a) Applicability of this section. This section applies to each aircraft operation conducted in an aircraft with a maximum certificated takeoff weight of 12,500 pounds or more except for those operations specified in § 1550.5 and those operations conducted under a security program under part 1544 or 1546 of this chapter.
(b) Procedures. Any person conducting an operation identified in paragraph (a) of this section must conduct a search of the aircraft before departure and screen passengers, crewmembers, and other persons and their accessible property (carry-on items) before boarding in accordance with security procedures approved by TSA.
(c) Compliance date. Persons identified in paragraph (a) of this section must implement security procedures when notified by TSA. TSA will notify operators by NOTAM, letter, or other communication when they must implement security procedures.
(d) Waivers. TSA may permit a person conducting an operation identified in this section to deviate from the provisions of this section if TSA finds that the operation can be conducted safely under the terms of the waiver.