Direct Answer — What §43.10 Requires on Removal
14 CFR §43.10 controls the removed part, not the installed life limit. When you remove a life-limited part from a type-certificated product, §43.10(c) requires you to control it using one of seven methods so it cannot be reinstalled beyond its limit; §43.10(d) requires the life-status record to travel with the part when you sell or transfer it.
- §43.10(a) defines a life-limited part as any part for which a mandatory replacement limit is specified in the type design, the Instructions for Continued Airworthiness, or the maintenance manual; life status is the accumulated cycles, hours, or other mandatory limit of that part.
- §43.10(b) — no disposition is required when a part is temporarily removed and reinstalled and all three conditions hold: life status unchanged, same serial-numbered product, and the product accumulates no time in service while the part is off.
- §43.10(c) — control the removed part by one of seven methods: a recordkeeping system, an attached tag/record, non-permanent marking, permanent marking, segregation, mutilation, or any other FAA-approved or accepted method.
- §43.10(d) — when the part is sold or transferred, the mark, tag, or other record used to comply with the section must transfer with it, unless the part is mutilated first.
Source: 14 CFR §43.10 — eCFR. Verify the current text before acting; this guide paraphrases the rule and does not reproduce it as a substitute for the regulation.
Most aviation operators know they have to track a life limit. Fewer have a disciplined answer to a different question: the instant a turbine disk, rotor hub, or life-limited landing gear member comes off the aircraft, what controls it so it never quietly finds its way back onto a different airframe as if it were fresh? That is the job of 14 CFR §43.10, and it is a distinct obligation from the status-tracking rule.
This guide is the removal and disposition half of the life-limited parts story. For the running status side — what §91.417(a)(2)(ii) requires you to record about an installed part, the retention rules, and why missing paperwork is treated as zero remaining life — see our companion guide, Life-Limited Parts Records: Current Status, Life Status, and the §43.10 Transfer Rules. Here we go deep on §43.10(c) control methods, the §43.10(b) temporary-removal exception, the §43.10(d) transfer rule, and the difference between segregating a part and mutilating it. Throughout, the maintenance entry that documents the removal itself is a §43.9 record-entry obligation that runs in parallel.
The Seven §43.10(c) Control Methods
After April 15, 2002, each person who removes a life-limited part from a type-certificated product must control the part using one of these methods. Four preserve the part with its life history intact; segregation and mutilation are about preventing reuse; the seventh is the FAA-approved catch-all. You apply one — but the documentation methods and the prevention methods are often paired in practice.
Recordkeeping system
§43.10(c)(1)Control the part through a recordkeeping system that substantiates the part number, serial number, and current life status of the part. This is the documentation-first method: the part itself may be physically unmarked, but a maintained record — electronic, paper, or otherwise — ties the specific serial number to its accumulated life so it can be established at any time.
Records implication
The record must substantiate part number, serial number, and current life status. A list that omits the serial number cannot control an individually tracked part.
Tag or record attached to the part
§43.10(c)(2)Attach a tag or other record to the part carrying the part number, serial number, and current life status. This is the most common stores-and-quarantine practice: a physical tag travels with the part so anyone handling it can read its remaining life without consulting a separate system.
Records implication
The tag is the record. Under §43.10(d), this tag must travel with the part if it is later sold or transferred — losing it strips the part of its traceable life.
Non-permanent marking
§43.10(c)(3)Legibly mark the part using a non-permanent method showing its current life status. If you choose marking, §45.16 directs you to the design-approval holder for marking instructions — because an improper mark on a stressed component can itself become a defect.
Records implication
Marking method and content should follow the manufacturer instructions made available under §45.16. The mark must be legible to be a valid control.
Permanent marking
§43.10(c)(4)Legibly mark the part using a permanent method showing its current life status. Permanent marking is durable across handling and storage, but it must not compromise the structural or functional integrity of the part — which is exactly what §45.16 is designed to govern.
Records implication
Permanent marking still must comply with the manufacturer marking instructions referenced by §45.16; some parts cannot be permanently marked without damage.
Segregation
§43.10(c)(5)Segregate the part using methods that deter its installation on a type-certificated product. In practice this is a physically separate, clearly identified quarantine area or container reserved for parts not eligible for installation, keeping them apart from serviceable stock so they cannot be picked by mistake.
Records implication
Segregation deters reuse but does not by itself preserve life-status traceability — pair it with a record so the part can be re-established if it still has life.
Mutilation
§43.10(c)(6)Mutilate the part to deter its installation in a type-certificated product. This is the terminal disposition used when a part has reached its mandatory limit and must never fly again. FAA guidance on disposition of unsalvageable parts (Advisory Circular 21-38) describes mutilation as destroying the part beyond the possibility of restoration.
Records implication
Mutilation is the one method that lets you separate the record from the part under §43.10(d) — once mutilated, the part cannot be sold or transferred for installation.
Any other FAA-approved or accepted method
§43.10(c)(7)Any other method approved or accepted by the FAA. This is the catch-all that lets an operator or repair station use an alternative control scheme — for example, a validated electronic chain-of-custody system — when it is approved or accepted by the FAA for the purpose.
Records implication
The method must be approved or accepted by the FAA. Do not assume an in-house process qualifies without that basis.
Marking is governed at the source by §45.16
If you control a removed part by marking it — methods (c)(3) or (c)(4) — 14 CFR §45.16 (Marking of life-limited parts) requires the holder of the type certificate or other design approval, when requested by a person required to comply with §43.10, to make available the instructions for marking the part — or to substantiate that the part cannot be marked without compromising its structural or functional integrity. A mark applied to a stressed component the wrong way can itself become a defect, which is why the rule routes marking method back to the manufacturer. If a part cannot be safely marked, that fact is documented and you control it by a tag, a recordkeeping entry, segregation, or mutilation instead.
The §43.10(b) Temporary-Removal Exception — All Three Conditions
§43.10(c) does not fire every time a life-limited part is touched. §43.10(b) provides a narrow exception: when a part is temporarily removed and reinstalled, no disposition action is required if all three of the following conditions are met. Miss any one, and you are back under the (c) control requirement.
Life status has not changed
The accumulated cycles, hours, or other mandatory measure on the part is identical when it goes back on. If you log additional life against the part, the exception no longer applies.
Reinstalled on the same serial-numbered product
The part returns to the exact same type-certificated product it came from — identified by serial number. The moment it goes onto a different airframe, engine, or appliance, it is a removed part under (c).
No time in service accumulated while the part is off
The product does not accumulate time in service during the period the part is removed. A part pulled to access something behind it, then reinstalled before the next flight, fits. A part removed while the aircraft is flown does not.
The exception is about access work — not stores returns
The §43.10(b) carve-out is meant for the routine reality of pulling a part to reach something behind it and putting the same part back on the same aircraft before it flies. It is not a license to move a removed part into stores, fit it to a different tail, or set it aside while the aircraft continues flying without it. As soon as the part leaves that closed loop, it must be brought under a §43.10(c) control method — and the removal/installation should still be captured in a §43.9 maintenance entry.
§43.10(d) — The Record Belongs to the Part
§43.10(d) is the rule that makes the whole system work across changes of ownership. It provides that each person who removes a life-limited part from a type-certificated product and later sells or otherwise transfers that part must transfer with the part the mark, tag, or other record used to comply with the section — unless the part is mutilated before it is sold or transferred. The life-status documentation is not the seller's to keep; it is an attribute of the part, and it has to follow the part to every subsequent custodian.
Compliant transfer
- The §43.10(c) tag, marking, or recordkeeping entry accompanies the part to the buyer.
- Part number, serial number, and current life status are legible and substantiated.
- The buyer can establish remaining life and lawfully reinstall the part.
- The installing mechanic captures the part and its life status in the §43.9 install entry.
Untraceable transfer
- Part sold with no tag, no legible marking, and no retrievable life-status record.
- Remaining life cannot be established from documentation.
- No A&P or IA can lawfully approve the aircraft for return to service with it installed.
- For installation purposes the part is scrap — regardless of its true mechanical condition.
This is also where life-limited parts intersect with parts traceability and FAA Form 8130-3 and the receiving-inspection discipline at a Part 145 repair station. A used life-limited part entering a facility without its §43.10(d) traceability is the classic suspect-part scenario: it may be perfectly serviceable, but without the record, it cannot be established as within limits. The companion life-status records guide covers why that gap is treated as zero remaining life on the airframe side.
Keep every life-limited part's record where it belongs — with the part
FileFlo classifies and indexes aviation maintenance documents against the governing CFR — life-limited parts status records, tags, 8130-3 traceability, and the §43.9 entries that document removal and installation — and surfaces the gaps before an FSDO inspector does. See the full Aviation compliance coverage.
Segregation vs. Controlled Mutilation — Two Very Different Endings
Segregation (§43.10(c)(5)) and mutilation (§43.10(c)(6)) are both listed as control methods, but they sit at opposite ends of a part's life. Confusing them is one of the most consequential mistakes in parts disposition, because one is reversible and the other is terminal.
Segregation — reversible quarantine
§43.10(c)(5): segregate the part using methods that deter its installation on a type-certificated product. In practice, a physically separate, clearly labeled quarantine area or bin that keeps not-eligible parts away from serviceable stock. A segregated part still exists; if its life status can later be re-established and it has remaining life, it can be recovered. Segregation deters reuse but does not, by itself, preserve traceability — so it is normally paired with a tag or record.
Mutilation — terminal disposition
§43.10(c)(6): mutilate the part to deter its installation in a type-certificated product. This is the end-of-life method — used when a part has reached its mandatory limit and must never fly again. FAA guidance on disposition of unsalvageable parts (Advisory Circular 21-38) describes mutilation as destroying the part so it cannot be restored to a usable condition. Once mutilated, the part is closed out: it is the one method that lets you separate the record from the part under §43.10(d).
When you would reach for each method
| Scenario | Typical §43.10(c) method |
|---|---|
| Part removed with remaining life, returning to stores | Tag/record (c)(2) — life status travels with it |
| Part removed pending re-establishment of life status | Segregation (c)(5) + a record |
| Part at or past its mandatory limit | Mutilation (c)(6) — must never fly again |
| Part removed and reinstalled, same tail, no time in service | None required — §43.10(b) exception |
| Validated electronic chain-of-custody program | Other FAA-approved/accepted method (c)(7) |
Methods are illustrative of common practice; §43.10(c) requires one of the listed methods but does not dictate which scenario maps to which method. Operators document their chosen approach in their maintenance or quality procedures.
Mutilation is not the same as "rebuilt" or "zero-time"
A separate point of confusion: ending a part's life by mutilation has nothing to do with resetting a life. A life-limited part's mandatory limit cannot be reset by overhaul or repair. Granting an engine zero time is a distinct concept under 14 CFR §91.421, which permits a new maintenance record with zero time only when an engine is rebuilt by the manufacturer or by an agency approved by the manufacturer — and even then, the published life limits of life-limited parts inside that engine still stand. Mutilation closes a part out; it never opens life back up. See our engine and propeller overhaul time-tracking guide for how time-since-overhaul differs from a hard life limit.
Who §43.10 Applies To — and Where the Risk Concentrates
§43.10 is part of the maintenance rules in 14 CFR Part 43, so it binds anyone who removes a life-limited part from a type-certificated product, regardless of the operator's certificate. What changes across operations is the apparatus that keeps the removed part controlled and its record traveling with it.
Part 91 owners and corporate flight departments
A Part 91 owner is responsible under §91.403 for the airworthiness of the aircraft, which includes ensuring removed life-limited parts are controlled and that the installed parts' life status is tracked under §91.417 aircraft records. The most common failure is a part pulled during maintenance and set aside without a tag, then later sold or fitted elsewhere with no traceable life. The corporate flight department that runs a clean parts-quarantine process avoids creating its own suspect parts.
Part 135 operators and CAMP fleets
A Part 135 CAMP must account for life-limited parts across a fleet by serial number, which makes removed-part control a program discipline rather than a one-off. The Director of Maintenance is accountable for ensuring a part removed from one tail does not migrate to another without its life status — and that parts reaching their limit are mutilated rather than left in inventory. This sits alongside the broader Part 135 records the operator must keep.
Part 145 repair stations
A repair station that removes or installs life-limited parts must both produce a correct §43.9 maintenance entry and apply §43.10 disposition control to the removed part. Receiving inspection is where §43.10(d) is tested in practice: a used life-limited part arriving without its tag or record is a suspect part. This is exactly what an inspector probes in the Part 145 audit binder and the station's quality control manual.
Frequently Asked Questions
What does 14 CFR §43.10 actually regulate — and how is it different from tracking a life limit?
14 CFR §43.10 governs what happens to a life-limited part at the moment it is removed from a type-certificated product — the disposition, control, marking, and transfer of the removed part — so that a part with accumulated life can never be reinstalled somewhere else as if it were fresh. That is a different obligation from tracking the running life status of an installed part, which is a §91.417(a)(2)(ii) records duty. §43.10 has four paragraphs: (a) defines the terms, (b) carves out a narrow temporary-removal exception, (c) lists the control methods you must apply when you remove a part, and (d) requires the life-status record to travel with the part when you sell or transfer it. If you only track the limit but never control the removed part, you have satisfied half the rule. We cover the tracking half in our companion guide on life-limited parts records; this guide is the removal-and-disposition half.
What are the methods §43.10(c) allows for controlling a removed life-limited part?
After April 15, 2002, §43.10(c) requires each person who removes a life-limited part from a type-certificated product to control the part using one of the methods listed in the paragraph. The methods are: (c)(1) a recordkeeping system that substantiates the part number, serial number, and current life status; (c)(2) a tag or other record attached to the part carrying the part number, serial number, and current life status; (c)(3) legibly marking the part by a non-permanent method showing its current life status; (c)(4) legibly marking the part by a permanent method showing its current life status; (c)(5) segregating the part using methods that deter its installation on a type-certificated product; (c)(6) mutilating the part to deter its installation in a type-certificated product; or (c)(7) any other method approved or accepted by the FAA. The first four methods preserve the part with its history intact; the last two are about preventing reuse, with mutilation being the terminal one.
What is the difference between segregation and mutilation under §43.10(c)?
Both are §43.10(c) control methods, but they are not equivalent. Segregation under §43.10(c)(5) means storing the part using methods that deter its installation on a type-certificated product — for example, a physically separate, labeled quarantine area or bin reserved for parts not eligible for installation. A segregated part still exists and could, in principle, be recovered if its life status is later re-established. Mutilation under §43.10(c)(6) means rendering the part so that it cannot be installed in a type-certificated product — it is the end-of-life method, used when a part has reached its mandatory limit and must never fly again. The regulatory text frames mutilation as deterring installation; FAA guidance on parts disposition (for example Advisory Circular 21-38, which addresses disposition of unsalvageable aircraft parts) describes mutilation as physically destroying the part beyond the possibility of restoration. Segregation buys you time and traceability; mutilation closes the part out permanently.
When can I remove and reinstall a life-limited part without doing any §43.10(c) disposition?
Only under the narrow exception in §43.10(b). No disposition is required when a life-limited part is temporarily removed and reinstalled and all three conditions are met: the life status of the part has not changed; the removal and reinstallation is performed on the same serial-numbered product; and that product does not accumulate time in service while the part is removed. The classic case is removing a component to gain access to something behind it, then putting the exact same part back on the same aircraft before it flies again. The moment any one of those conditions breaks — the part goes onto a different airframe, the aircraft flies with the part off, or the life status is updated — you are out of the (b) exception and back under the (c) control requirement. This is why a part pulled and set on the bench during an inspection is treated very differently from a part removed for return to stores or for installation elsewhere.
When I sell or transfer a removed life-limited part, what must go with it under §43.10(d)?
Per 14 CFR §43.10(d), each person who removes a life-limited part from a type-certificated product and later sells or otherwise transfers that part must transfer with the part the mark, tag, or other record used to comply with the section — unless the part is mutilated before it is sold or transferred. In plain terms, the life-status record belongs to the part, not to you. Whatever you used under §43.10(c) to document the accumulated life — the attached tag, the marking, or the recordkeeping entry — must accompany the part to its next owner so they can establish remaining life. The only way to legitimately separate the record from the part is to mutilate the part first, which is itself a §43.10(c) method and means the part can never return to service. A used life-limited part offered with no traceable life status is, for installation purposes, scrap.
How does §43.10 connect to the maintenance record entry the mechanic signs?
They are complementary but separate. §43.10 controls the physical part and its traveling record. 14 CFR §43.9 governs the maintenance record entry the person makes for the act of removing or installing the part — the description of work, the date of completion, the name of the person performing the work when different from the approver, and the signature, certificate number, and kind of certificate of the person approving the work for return to service. When a mechanic removes a life-limited part, two things should happen: a §43.9 entry documents the removal in the aircraft records, and the removed part is brought under §43.10(c) control (tagged, marked, segregated, or mutilated). When a part is installed, the §43.9 entry should capture the part number, serial number, and life status of the installed part so the §91.417(a)(2)(ii) current-status record stays accurate. A clean removal that is logged under §43.9 but leaves the part uncontrolled under §43.10 is still a gap.
Does §45.16 require me to mark life-limited parts?
Not exactly — §45.16 places the obligation on the design-approval holder, not the mechanic in the field. 14 CFR §45.16, titled Marking of life-limited parts, requires the holder of a type certificate or other design approval for a life-limited part, when requested by a person required to comply with §43.10, to make available the marking instructions for the part, or alternatively to substantiate that the part cannot be marked without compromising its structural or functional integrity. So §45.16 is the supply-side counterpart to §43.10(c)(3) and (c)(4): if you choose to control a removed part by marking it, the manufacturer is the source of how to mark it safely. If a part genuinely cannot be marked without damaging it, that is documented, and you control the part by one of the other §43.10(c) methods — a tag, a recordkeeping entry, segregation, or mutilation — instead.
Can a removed life-limited part with remaining life be returned to service, and what proof is needed?
Yes — a removed life-limited part that still has remaining life can be reinstalled, but only if its life status is fully traceable. The part must carry, or be accompanied by, the §43.10(c) record that substantiates its part number, serial number, and accumulated life status, and that record must allow the installer to confirm the part is below its mandatory limit. On installation, the person making the §43.9 entry records the part and its life status, and the aircraft's §91.417(a)(2)(ii) current-status record is updated to reflect the installed part. If the traceability is broken — the tag is gone, the marking is illegible, the recordkeeping entry cannot be produced — the part cannot be established as within limits, and an A&P or IA cannot lawfully approve the aircraft for return to service with it installed. In that state the part is treated as if it has no usable life, regardless of its true mechanical condition. This is the central reason the §43.10(d) transfer rule exists: the record has to survive every change of custody.
Related Aviation Records Reading
Life-Limited Parts Records (Tracking Side)
Current status, §91.417(a)(2)(ii), and why missing paperwork = zero life
14 CFR §43.9 Maintenance Record Entry Requirements
The entry that documents a removal or installation
Airworthiness Directive Compliance Records
AD-driven part removals and the records they generate
PMA Parts Traceability + FAA Form 8130-3
Chain-of-custody for parts entering inventory
Engine & Propeller Overhaul Time Tracking
Why time-since-overhaul is not a hard life limit
Part 91 Aircraft Records Requirements
§91.417 maintenance and life-status records
Aviation Records Retention Schedule
Which records are permanent vs. one-year
Part 145 Repair Station Recordkeeping
Receiving inspection and disposition control
Prove every removed part's life status is documented — before the inspector asks
FileFlo is a compliance document intelligence platform that classifies and indexes aviation maintenance records against the governing CFR — life-limited parts status records and tags, 8130-3 traceability, §43.9 removal and installation entries, and §91.417 retention clocks. It tracks expirations, flags missing traceability, and generates an inspector-format audit binder on demand. It does not perform maintenance, hold your certificate, or replace your safety program — it makes your records audit-ready and proves them. Starter $89/month · Professional $299/month · 5-day free trial, no credit card required.