Life-limited part
Life-limited part means any aircraft part that has an established replacement time, inspection interval, or other time-related procedure associated with it. For non-military parts, the FAA specifies life-limited part airworthiness limitations in 14 CFR 21.50, 23.1529, 25.1529, 27.1529, 29.1529, 31.82, 33.4, and 35.5, and on product Type Certificate Data Sheets (TCDS). Letters authorizing Technical Standards Orders (TSO) must also note or reference mandatory replacement or inspection of parts.