FAA Certifies More Durable Hardware for CFM LEAP-1A Engine

Sometimes the hardest thing to correct for is the thing you cannot see.

Case in point: fine airborne particles, some no wider than one-tenth the width of a human hair. Otherwise known as dust — the kind naturally suspended in the first few thousand feet of air, where commercial jet engines can ingest it during takeoff. Over time, and especially in hot and harsh environments around the world, these particles can work their way into an engine’s core, wearing down crucial components and affecting its efficiency and durability.

After listening to feedback from customers (particularly in the Middle East), studying the effects, and testing rigorously, CFM International, a 50-50 joint company between GE Aerospace and Safran Aircraft Engines, took aim at these tiny particles and came up with a solution. On December 6, the U.S. Federal Aviation Administration certified an improved high-pressure turbine (HPT) hardware durability kit developed by the company for CFM LEAP-1A engines that power the Airbus A320neo family of aircraft.

The durability kit — which includes the HPT stage 1 blade, HPT stage 1 nozzle, and forward inner nozzle support — will help bolster the LEAP-1A engine’s durability and time on wing, helping customers keep their fleets flying especially in hot and harsh environments. 

“This new hardware is fulfilling our promise to ensure that LEAP-1A engines achieve the same level of maturity, durability, and time on wing that our customers have enjoyed with the CFM56 product line,” says Gaël Méheust, president and chief executive officer at CFM International. 

Development required around 15 years of lab work, analyzing millions of hours of field data, concocting a homemade compound that mimics the effects of the earthly dust particles (what GE Aerospace engineers affectionately call “pixie dust”), and subjecting a series of LEAP-1A engines to a battery of dust ingestion simulations in test cells.

Carlos Perez, senior director of engineering for LEAP engines at GE Aerospace, who worked on the tests at company headquarters in Cincinnati, noted in an article last year that “the dust tests on LEAP-1A engines are some of the longest endurance tests we’ve ever run in terms of simulating the environments we see in the Middle East.”

Installed in the core of the engine, HPT blades spin at thousands of revolutions per minute (RPM) in temperatures hot enough to melt wrought iron, powering the compressor that feeds air into the combustion chamber. Ultimately, the dust ingestion tests were able to replicate the wear on the LEAP-1A engine’s HPT stage 1 blade that operators were seeing in the field. 

And seeing how and where that was affecting the components enabled the engineers to make subtle but significant changes, optimizing the casting and cooling of the HPT blade and improving the design of the blade tip and trailing edge. Adjustments were also made in the HPT stage 1 nozzle and forward inner nozzle support to ensure that the whole system is more durable.