Type Certificate (TC), including Supplemental Type Certificate (STC), Holders must:

• Make available airplane or rotorcraft flight manual to the owner at the time of delivery (14 CFR 21.5)
• Make a type certificate available for examination upon request of the FAA or the National Transportation Safety Board (14 CFR 21.49)
• Make required design changes if the FAA issues an Airworthiness Directive and make descriptive data covering these changes to all operators of the product (14 CFR  21.99)
• Make information on approved design changes that contribute to the safety of the product available to all operators of the product (14 CFR 21.99)