Regulation Text
(a) The owner or operator may use a new maintenance record, without previous operating history, for an aircraft engine rebuilt by the manufacturer or by an agency approved by the manufacturer.
(b) Each manufacturer or agency that grants zero time to an engine rebuilt by it shall enter in the new record—
(1) A signed statement of the date the engine was rebuilt;
(2) Each change made as required by airworthiness directives; and
(3) Each change made in compliance with manufacturer's service bulletins, if the entry is specifically requested in that bulletin.
(c) For the purposes of this section, a rebuilt engine is a used engine that has been completely disassembled, inspected, repaired as necessary, reassembled, tested, and approved in the same manner and to the same tolerances and limits as a new engine with either new or used parts. However, all parts used in it must conform to the production drawing tolerances and limits for new parts or be of approved oversized or undersized dimensions for a new engine.
Research Notes
Section 91.421 — Rebuilt engine maintenance records — addresses the recording requirements when an engine is rebuilt (as opposed to overhauled).
Rebuild vs Overhaul: An 'overhauled' engine is disassembled, inspected, and reassembled with new or serviceable used parts per the manufacturer's manual. A 'rebuilt' engine is a more significant action — typically performed by the manufacturer or an FAA-approved rebuilder — that returns the engine to 'zero time' status.
Zero-time engine: A rebuilt engine carries a new logbook starting at zero hours. This is a manufacturer privilege; only the engine manufacturer (or an FAA-authorized agency under specific circumstances) can make this determination.
What gets recorded: The new logbook starts with the manufacturer's rebuild record. The previous engine records are not transferred (because the engine is legally a 'new' starting point).
Reference: AC 43.13-1B on aircraft engines; FAA Order 8900.1.
Amendment History
Amendment History Coming Soon
Every time this regulation changes, we'll record it here — the date, what was amended, and a plain-English summary of what shifted.