CFM56-7B borescope inspection: scope, findings and reports

The engine in brief

Item	CFM56-7B
Aircraft	Boeing 737 Next Generation: 737-600, -700, -800 and -900
Architecture	Two-shaft turbofan: fan and three-stage booster, nine-stage high-pressure compressor, annular combustor (single, or an optional double annular), single-stage HPT and four-stage LPT
Core	Shared with the CFM56-5B on the Airbus A320 family
Later build	The CFM56-7BE "Evolution", introduced in 2011 with improved HPT and LPT airfoils

What a borescope inspection covers

Module	Typical focus
Fan and booster	Impact damage, nicks, dents and erosion on blades
High-pressure compressor	Nicks, dents, tip curl, erosion and missing material on blades and vanes
Combustor	Cracks, burning and coating loss on the liner and dome, and fuel nozzle condition
High-pressure turbine	Coating loss, burning, cracks and erosion on nozzle guide vanes and blades
Low-pressure turbine	Cracks, burning and other damage on blades and vanes

This is a summary, not a procedure. The aircraft maintenance manual sets the exact ports, stages, tasks and limits.

2026 FAA proposals that affect the CFM56-7B

Proposal	What it covers	Inspection method	Status
FAA-2026-8803	The rotating air HPT front seal, on engines with certain HPT inner stationary seals	Borescope	Proposed September 14, 2026; comments close October 29, 2026
FAA-2026-7232	Fan blade dovetails, replacing AD 2018-26-01	Ultrasonic or eddy current, not borescope	Proposed July 31, 2026; comments closed August 31, 2026

The fan blade proposal keeps the structure of the directives issued after Southwest Flight 1380 in 2018. That means an initial inspection before a blade reaches 17,000 cycles since new, then at least every 1,600 flight cycles. The updated CFM procedures cover more of the dovetail. By the FAA's estimate it applies to 4,553 engines on US-registered aircraft, at 2 work-hours, or $340, per engine.

What a -7B borescope report should record

• Engine model and thrust rating, serial number, position, and cycles since new and since the last shop visit.
• The manual revision and task numbers used, and any AD or service bulletin the inspection answers.
• Module and stage for every finding, with images, measurements and the limit applied.
• A disposition for each module, and any repeat-inspection interval with its cycle count.
• The inspector's name, certificate and signature.

Download the free report template, or see what any borescope inspection covers.

A common finding

Coating loss on HPT hardware is a common hot-section finding. See TBC spallation: what it looks like on a borescope.

Where AirCheck fits

AirCheck's engine map uses the same modules: fan, LPC, HPC, combustor, HPT, LPT and nozzle. It records each finding by stage against the manual and produces the report your inspector signs. Need a CFM56-7B inspection? Tell us the engine and where it is.