Aerospace Garage

PRODUCT PROFILE

LEAP-1B

CFM International LEAP-1B
Photo: Thyrome / Wikimedia Commons · CC0

HIGH-BYPASS TURBOFAN ENGINE

LEAP-1B

France / United States · verified

MAKER

CFM International →cfmaeroengines.comlast verified 6 Sept 2026
COUNTRY
France / United States
PROGRAMME STATUS
verified

Specifications

Function
Propulsion and auxiliary power generation for narrow-body commercial aircraft.
Architecture
Two-shaft turbofan featuring a 1.76-metre fan and a high-pressure ratio compressor.
Platform fit
Sole source powerplant for the Boeing 737 MAX 7, 8, 9, 10, and 8-200 variants.
Commercial model
Sold as original equipment with heavy emphasis on manufacturer-led lifecycle maintenance contracts.
Deployment status
In active mass production and global commercial service.
Evidence to demand
Backed by a multi-thousand unit order backlog and the high operational frequency of the 737 MAX fleet.

Description

The LEAP-1B is a high-bypass turbofan engine produced by CFM International, the long-standing joint venture between GE Aerospace of the United States and Safran Aircraft Engines (Safran S.A.) of France. It represents the successor to the CFM56-7B, incorporating carbon-fibre composite fan blades and Additive Manufacturing (3D-printed) fuel nozzles. This specific model is the exclusive powerplant for the Boeing 737 MAX family, featuring a smaller fan diameter than its sister variants to accommodate the lower ground clearance of the 737 airframe. Procurement is handled through direct sales to airlines and leasing firms, typically bundled with long-term Rate-Per-Flight-Hour (RPFH) service agreements. Major global operators include Southwest Airlines, United Airlines, Ryanair, and Lion Air. The engine is a corner-stone of the narrow-body commercial market, designed to offer a significant double-digit reduction in fuel consumption and CO2 emissions compared to previous generation single-aisle aircraft engines. Buyers must monitor the technical health of the fleet following historical issues related to high-pressure turbine durability and carbon buildup in fuel nozzles. The Aerospace Garage desk would verify the specific hardware standards (Mod Status) of any second-hand unit, as earlier production batches have undergone multiple service bulletin updates. Prospective owners should also confirm the current status of the manufacturer's supply chain, which has previously impacted the delivery schedule of new-build shipsets.

Linked stories

LAST VERIFIED

6 Sept 2026

SOURCE CITATION

Maker website on record

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