Buyer's guide

Buying CFM56 parts: LLPs, hot-section parts and LRUs for the CFM56-5B and -7B, the paperwork each needs, and what to put on the RFQ

By the MG AVIATION TECH team · Published · 10 min read

"CFM56 part" covers a disk worth its remaining cycles, a turbine blade whose value depends on who repaired it, and a fuel-control unit that is bought like any other rotable. Each is quoted, documented and accepted differently. This guide sorts CFM56-5B and -7B parts into those three groups, lists the paperwork each needs, explains where PMA parts and DER repairs fit, and ends with a checklist for the RFQ and the purchase order.

Start with the exact engine model

The two CFM56 models most buyers deal with today are the CFM56-5B, which EASA's type-certificate data sheet pairs with the Airbus A318, A319, A320 and A321, and the CFM56-7B on the Boeing 737 Next Generation. The older CFM56-5A has its own EASA data sheet (E.067); the CFM56-5C shares the -5B's (E.003). "CFM56" alone on an RFQ is not enough, because inside each series the data sheets list many models with suffixes that change parts:

  • Thrust rating: the number after the series (-7B24, -7B26, -7B27; -5B4, -5B6 and so on). Some LLP lives are shorter at higher ratings.
  • Combustor: "SAC" (single annular) and "DAC" (dual annular) engines, the /2 models on the -7B and /2P on the -5B.
  • Build standard: "TI" (Tech Insertion; the /3 models, which the -5B data sheet also lists) and, on the -7B, the "E" models certified from 2010. The EASA data sheet gives different FADEC software part numbers for SAC, DAC, TI and E engines.
  • Military -7B27A models. EASA's data sheet states that the CFM56-7B27A, -7B27A/3 and -7B27AE are designed for military applications only, and that installing their used parts in another CFM56-7B model is subject to EASA's prior approval. A used part offered "from a -7B27A" is a question for your engineering before it is a price.

Put the engine model (and, for an LLP, the thrust rating it will run at) on the RFQ line. It lets the seller check effectivity instead of guessing.

Three kinds of CFM56 part, three sets of paperwork

GroupExamplesWhat decides its valuePaperwork to ask for
Life-limited parts (LLPs)Fan disk, booster spool, fan shaft, HPC spools and disks, HPT disk and shafts, LPT disks and shaftCycles remaining against the limit for that part number at your rating, and the records that prove themRelease certificate, back-to-birth records, life-status sheet, incident/accident clearance statement
Hot-section and gas-path parts (not life-limited)HPT blades, HPT nozzle guide vanes, LPT nozzle segments, HPT shrouds, sealsCondition, the repair data it was repaired to, and whether it is OEM, PMA or repaired to DER data8130-3 or EASA Form 1 stating the work done and the data used; shop findings; trace
LRUs and accessoriesHydromechanical unit (HMU), main fuel pump, starter, FADEC control unit, valves, sensorsCondition (OH, SV, NE), modification status, software part number where there is one8130-3 or EASA Form 1; shop teardown report for OH or repaired units; SB status

Two boundaries trip up RFQs. The starter is part of the -7B engine type design, per its EASA data sheet. The IDG and the engine-driven hydraulic pump are aircraft equipment: the data sheets list only their drives on the engine gearbox, under "Aircraft Accessory Drives" (the -5B sheet names the IDG and hydraulic pump; the -7B sheet, aircraft electrical and hydraulic generation). Look them up in the aircraft's parts catalog, not the engine's.

LLPs: the limit belongs to the part number

Under 14 CFR 33.70, engine life-limited parts are "rotor and major static structural parts whose primary failure is likely to result in a hazardous engine effect", typically disks, spacers, hubs, shafts, high-pressure casings and non-redundant mount components. The manufacturer publishes each part's approved life in the Airworthiness Limitations Section; for the CFM56-5B and -7B, EASA's data sheets point to chapter 5 of the Engine Shop Manual.

An engine-type guide from Aircraft Commerce (June/July 2008) counted 18 LLPs in the -7B and made two points that still shape how to read a quote: each LLP exists in several part numbers with different certified lives, and some lives are shorter for higher-thrust ratings. So "12,000 cycles remaining" means little until you know the part number, the limit it was measured against and the rating. Ask for cycles remaining at your engine model and rating, on a status sheet you can check.

Whoever removes an LLP must keep it under control with a record, tag or marking showing part number, serial number and current life status (14 CFR 43.10), and AC 20-62E says the historical records establishing time and cycles "must be provided as evidence". What a full back-to-birth pack holds, who signs each document and where chains break is in our back-to-birth traceability guide; we do not repeat it here.

Hot-section parts: the repair decides what you are buying

HPT blades, vanes, nozzle segments and shrouds are not life-limited, but they wear, and most used ones have been repaired. Three questions matter more than the condition code:

  1. Who designed the part? OEM or PMA. FAA PMA alternatives now reach the CFM56-5B/-7B hot section: in October 2025 a PMA holder announced FAA approval of an HPT blade and said it already held PMAs for the HPT nozzle guide vane, the LPT stage 1 nozzle guide vane and the HPT shroud. Whether you may install one is set by your operator's program, your authority and, on a leased engine, the lease. Our PMA guide covers EASA acceptance and typical lease wording.
  2. Whose data was it repaired to? The OEM's repair (CFM said in October 2025 it had industrialized about 400 CFM56 part repairs since early 2023), or a repair approved by an FAA Designated Engineering Representative (DER) and documented on FAA Form 8110-3. The part keeps its identity either way; what differs is the repair data. Some programs, customers and leases accept OEM repairs only, so ask for the repair reference on the release.
  3. Was the repair done right? An EASA notice from 2014 described a CFM56 HPT forward seal (P/N 1282M72P05) whose repair left plasma coating "thicker than the engine overhaul manual limits" and possible missed cracks. The release names the shop; the shop's findings and the repair it applied are what you check.

Supply is tight. Aviation Week reported on 31 August 2026 that HPT blade availability had become the biggest factor in CFM56 overhaul turnaround and that used HPT blades with around 10,000 or more cycles remaining were increasingly difficult to source. Expect quotes to mix new OEM, PMA and repaired blades, and read each line for which one it is.

LRUs and accessories: bought like rotables

The HMU, fuel pump, starter, valves and control units come with an overhaul or repair history rather than a life limit. What to ask:

  • Exact part number and dash, checked against the engine model. Control units also carry software: the -7B data sheet lists different FADEC software part numbers by build standard, so state the hardware and software configuration you need.
  • Condition and release. OH should come with a shop teardown report stating what was replaced; SV or "inspected/tested" means less work was done. See our condition code guide.
  • SB and AD status, which AC 20-62E lists among the records to obtain for a used part.
  • Exchange or outright, and the core terms if exchange. Our exchange and core charge guide covers those.

Used serviceable material: where it comes from, and why it is not getting easier

Used serviceable material (USM) comes from teardowns of engines taken out of service. A part removed at teardown is "as removed" (AR) until an appropriately certificated shop inspects, repairs or overhauls it and releases it; AC 20-62E says a used part's records should include a maintenance release or return-to-service tag from an FAA-certificated person. An AR part is a core, not an installable part.

The usual assumption is that retirements will flood the market with used CFM56 parts. Current reporting says otherwise. On 22 September 2026 Aviation Week quoted GE Aerospace's CFO saying CFM56 retirements were tracking at "somewhere between 1.5% to 2%" this year, down from the 3% to 4% GE projected for 2026 last year and the 2% to 3% it cut that to at the start of the year; he put CFM56 shop visits for this year and next at "probably closer to 2,400", up from about 2,300 projected. Aviation Week's fleet data showed about 1,200 CFM56-powered aircraft parked or stored, roughly 1,000 of them with -5 or -7 engines. The picture is of engines being overhauled rather than retired, which keeps demand for used material high and its supply thin.

Two warnings for used engine parts

In August 2023 EASA warned that CFM56 parts distributed by a UK broker had come with falsified release certificates and told holders to confirm each certificate with the organization named on it. In March 2026 it reported that a consignment of CFM56, V2500, PW1100 and RB211 parts already declared non-airworthy, including critical and life-limited parts, was diverted before mutilation by someone impersonating the mutilation contractor; EASA published the part and serial numbers and said the parts "are to be considered unapproved". Check any serial number you are offered against that list, and verify the release with its issuer.

What suppliers put on engine hot-section quotes

From our quote data

In supplier quotes we received between mid-June and mid-September 2026, lines for engine hot-section parts (blades, vanes, nozzles, shrouds, disks; HPT, LPT and HPC) covered 388 distinct part numbers. About half were offered overhauled (OH), 33% new (NE) and 7% new surplus (NS). A certificate was named on just under half of the lines; EASA Form 1 appeared on 22% of all lines and FAA 8130-3 on 17%. That is unusual: across all other parts we received, 8130-3 is mentioned more often than Form 1, so for engine parts the EASA release is the more common one in what we receive. A trace was stated on 51% of lines. These figures come from what suppliers wrote on quotes, matched by text; they are not a review of any documents.

Engine parts such as HPT blades, LPT nozzle segments and a CFM56-7B HMU are among the parts our customers order from us. Half the hot-section lines we receive say nothing about the certificate unless the RFQ asks, so ask. Which release your registry needs is covered in 8130-3 vs EASA Form 1.

Checklist for the RFQ and the purchase order

Write these on the line, next to the part number, and repeat them on the PO so a short delivery is a non-conforming one.

ItemLLPHot-section partLRU / accessory
Engine model and thrust ratingRequiredRequiredRequired
Acceptable conditionsSV, OH or NENE, OH, repaired; say whichNE, OH, SV; say which
Release certificate8130-3, EASA Form 1 or dual, per your registrySame, stating the work doneSame
OEM / PMAOEM only unless your engineering says otherwise"OEM only" or "PMA acceptable: [PMA P/N]"State it
Repair dataRepairs to the part listed on the release"OEM repairs only" or "DER repairs acceptable", repair reference on the releaseShop report listing parts replaced
Life and historyBack-to-birth pack; cycles remaining at [model / rating]; minimum [N] cyclesHours or cycles since repair, if trackedTime since overhaul, if tracked
StatementsIncident/accident clearance (non-incident), non-militaryNon-incident as your customer requiresSame
AD / SB statusRequiredWhere applicableRequired
Copies before POFull packRelease and shop findingsRelease and teardown report
CommercialOutrightQuantity per set, if bought as a setOutright or exchange; core terms

For wording that applies to any part, see our RFQ guide and purchase order checklist.

Send your CFM56 list as it is

Send your RFQ to [email protected] in the file you already have (Excel, PDF, a scan or the email body, five lines or five hundred), with the engine model, acceptable conditions, OEM/PMA and repair requirements written next to each line. Your inquiry will be reviewed by a specialist within one business day. In our client portal, RFQ Radar, each quoted line shows condition, certificates and the country it ships from as the supplier stated them, and a purchase order carries a "certificate needed" tick per line and a note where you can list the documents you need. Check the copies against your program and your lessor's terms before you order.

Send your RFQ →

Our client portal, RFQ Radar, keeps every quote, order and invoice in one place.

Before you buy, check what certificates and trace come with each part. Aircraft on ground? See how our 24/7 AOG desk works.

Sources