CFM International announced it has successfully initiated ground testing of the first LEAP-1B engine that will exclusively power the Boeing 737 MAX. CFM ran the engine for the first time on June 13, three days ahead of schedule. The LEAP-1B engine, installed in a test cell at Snecma facilities in Villaroche, France, successfully completed a series of break-in runs before reaching full take-off thrust.
The engine will be on test for the next several weeks, as CFM verifies mechanical operations, stall margin, engine starts and further validates the advanced technologies incorporated in the engine, including the woven carbon fiber composite fan, the Twin-Annular, Pre-Mixing Swirler (TAPS) combustor, ceramic matrix composite shrouds in the high-pressure turbine and the titanium aluminide blades in the low-pressure turbine.
The LEAP-1B is specifically optimized for the 737 MAX with a smaller, highly efficient core and benefits from these new technologies. The LEAP-1B engine contributes significantly to the 737 MAX’s fuel efficiency improvement. The 737 MAX will be 14% more fuel efficient than today’s Next-Generation 737s – and 20% better than the original Next-Generation 737s when they first entered service.
Ok, how much of that improved “efficiency” is going to be eaten up by the MAXs heavier airframe, mostly due to the Leap engines and associated structure?
That depends on who you listen to.
How can LEAP-1B have the same fuel improvement as GTF if it’s bypass ration is only 9 compared to 12 with GTF and the fan size difference is 12 inches(69 compared to 81(? Someone must be overblowing things here, Maybe GTF got it wrong and they should have undersized the fans to 69 inches as well.