Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- CFM gets FAA and EASA certification for a more robust LEAP-1A turbine. December 10, 2024
- Global instability poses questions for aerospace industry December 9, 2024
- How Trump tariffs affected, and could affect, Airbus, Boeing and Embraer December 6, 2024
- Start-up hybrid plane OEM MAEVE teams with MHIRJ for sales, more December 5, 2024
- Production increase delays hurt Airbus costs December 2, 2024
CFM gets FAA and EASA certification for a more robust LEAP-1A turbine.
By Bjorn Fehrm
December 10, 2024, © Leeham News: CFM has announced that FAA and EASA have certified an upgrade to the LEAP-1A turbine, allowing the engine to stay on wing longer, especially in hot and harsh environments.
The upgrade was developed using a new dust ingestion method CFM developed to simulate the wear on the LEAP first turbine stage and nozzle in certain dusty environments.
CFM LEAP-1A with the booster bleed ports marked with (2) and the turbine that has been improved marked with (7). Source: CFM.
Bjorn’s Corner: New engine development. Part 28. Wrapup.
By Bjorn Fehrm
October 11, 2024, ©. Leeham News: We have done an article series on why engine development takes longer than airframe development. Part of the reason is that advancements in engine technology can deliver considerably higher fuel consumption reductions than airframe advancements.
The change of engines for the A320 series and 737 MAX delivered a 15% improvement in engine efficiency. In contrast, the airframe improvement was less than half, mainly by stacking cabin seats closer together.
Figure 1. The 4:1 gear ratio Utrafan demonstrator in the Rolls-Royce test cell. Source: Rolls-Royce.
Bjorn’s Corner: New engine development. Part 25. New versus old, CFM56 vs. LEAP
By Bjorn Fehrm
September 20, 2024, ©. Leeham News: We do an article series about engine development and why it has longer timelines than airframe development. It also carries larger risks of product maturity problems when it enters service than the airframe of an airliner.
In our look at examples of recent developments with problems and these put in a historical perspective, we compare the CFM56 to the LEAP, comparing their reliability and durability.
Figure 1. The CFM56 with its mid-span shrouded titanium fan. Source: CFM.
Bjorn’s Corner: New engine development. Part 24. New versus old, GTF versus V2500
By Bjorn Fehrm
September 13, 2024, ©. Leeham News: We do an article series about engine development and why it has longer timelines than airframe development. It also carries larger risks of product maturity problems when it enters service than the airframe of an airliner.
We have covered the engine’s different parts and their technology challenges. We now look at some examples of recent developments with problems and put them in a historical perspective.
“Hyper focus on reliability and durability out of the gates”
By Scott Hamilton
THE CFM Open Fan engine could be at least 20% more fuel efficient than today’s CFM LEAP and P&W GTF, CFM partners say. Credit: CFM.
Sept. 11, 2024, © Leeham News: GE Aerospace and Safran advance on the CFM RISE Open Fan engine with an overriding goal: “Our customers really want us to be hyper-focused on reliability and durability out of the gates.”
GE and Safran are developing a potentially game-changing engine and marketing it via the 50-50 joint venture, CFM International. The entry-into-service goal is 2035.
Customer demand for reliability and durability “out of the gates” is understandable. Engines produced by CFM, Pratt & Whitney and Rolls-Royce disappointed Airbus and Boeing customers operating the Airbus A320neo family, the Boeing 737 MAX and 787 and now the Airbus A350. Durability and/or technical issues plagued the CFM LEAP, Pratt & Whitney Geared Turbo Fan (GTF), Rolls-Royce Trent 1000 and now the RR Trent XWB-97. The giant GE9X engines on the Boeing 777X also suffered technical problems during the long, extended flight testing.
Operators protested as on-wing time fell short of promises. 787s, A220s, A320neos, and to a lesser extent Embraer E195-E2s were grounded as engines components failed, MRO shops backed up (displacing routine overhaul requirements on older engines) and new-production engines were diverted to replace those on grounded aircraft.
The CFM LEAP, GE and Safran promise, will provide a 20% reduction in fuel consumption and emissions. But the radical technology of an Open Fan gives airlines, lessors and even Boeing pause.
GE and Safran say they are progressing through development of the 35,000+ lb thrust engine but there is a lot of work to do to make it ready for service and give customers confidence.
Bjorn’s Corner: New engine development. Part 22. High Turbine technologies.
By Bjorn Fehrm
August 30, 2024, ©. Leeham News: We do an article series about engine development and why it has longer timelines than airframe development. It also carries larger risks of product maturity problems when it enters service than the airframe of an airliner.
We reached the turbine part on our way through the engine, where we last looked at high-pressure turbine temperatures. It’s the most stressed part of the engine and, in most cases, decides its durability. To understand why, we look closer at turbine technologies.
Figure 1. Our example engine, the LEAP-1A, is in cross-section with booster to compressor bleed valve area marked with a red circle. Source: CFM.
Bjorn’s Corner: New engine development. Part 21. The High Turbine.
August 23, 2024, ©. Leeham News: We do an article series about engine development and why it has longer timelines than airframe development. It also carries larger risks of product maturity problems when it enters service than the airframe. We discuss why.
In our journey through an engine, we have reached the turbine part, where we will dig deeper into the high-pressure turbine. This is the most stressed part of the engine and has a major influence on engine performance and durability.
Figure 1. Our example engine, the LEAP-1A cross-section with the high-pressure turbine marked. Source: CFM.
Bjorn’s Corner: New engine development. Part 20. Temperatures.
By Bjorn Fehrm
August 16, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have covered the different areas of a gas turbine except the exhaust (Figure 1). Before we go to the exhaust and the different outputs from a gas turbine Core, we look at the temperatures and how to cope with them in the different sections of a gas turbine.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.
Bjorn’s Corner: New engine development. Part 16. Compressor air use.
By Bjorn Fehrm
July 19, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have covered the problem areas of a compressor and how these achieve power-to-air-pressure conversion efficiencies of over 90% by using advanced 3D airflow modeling. Now, we look at the users of the air from the engin’s compressor.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.
Bjorn’s Corner: New engine development. Part 10. Propeller, Rotor or Fan?
By Bjorn Fehrm
June 7, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
Following the last Corner on airframe integration, several comments were made about the definition of propeller, open rotor, and/or fan. So, we’ll explore this further.
Figure 1. Evolution of Wright Brothers propellers from 1903 to 1905. Source: wright-brothers.org
