Reader Response Draft #3

The CFM56 series of engines is manufactured by CFM International, which is a 50-50 joint venture between Safran Aircraft Engines and GE Aerospace (CFM International, 2024,). The CFM company has produced several series in its engine family to cater to the needs of such aircraft including the military. Each series is a better, more updated version of its predecessor. According to the 2024 CFM Technical Manual Index (date of citation), the CFM56 engine series includes the CFM56-2A, 2B, and 2C series, the CFM56-3 series, the CFM56-5A, 5B, and 5C series, and the latest, the CFM56-7B series, which exclusively powers Boeing 737 Next Generation (737NG) single-aisle aircraft. The CFM56-7B can generate between 23,000 and 32,900 pounds of thrust (CFM International, 2024). According to an article by CFM’s website (2018), the CFM56-7B engine, which debuted on the Boeing 737 in 1997, has been a reliable workhorse in the airline industry. Collectively, this engine fleet has logged over 350 million flight hours.

I feel that given the long accumulated flight hours, the CFM56-7B has proven itself to be a reliable engine in the aviation industry. Even though it may not be the most advanced engine available today, it has built an excellent reputation based on its efficiency, high performance and reliability.

The CFM56-7B engine is renowned for its efficient design, making it a preferred choice for commercial aircraft like the Boeing 737. Building on the CFM56-3, the -7B incorporates advancements from the CFM56-5A/B series, including higher bypass ratios that range from 5.1 in lower thrust variants to 5.5 in higher thrust variants. This contrasts with the older -3 series, which had a bypass ratio between 4.9 and 5.0:1. Additionally, the engine features a two-shaft design with a 61-inch fan, a three-stage low-pressure compressor, a nine-stage high-pressure compressor, and turbine configurations that efficiently drive the fan and compressor. Full Authority Digital Electronic Control (FADEC) and support for 180-minute Extended-range Twin-engine Operations (ETOPs) also enhance its performance. The higher bypass ratio of the CFM56-7B increases fuel efficiency by generating more thrust from cooler air bypassing the engine core, resulting in lower fuel consumption and quieter operation due to reduced exhaust noise. This design not only makes the engine more efficient but also helps minimize carbon emissions, aligning with modern environmental standards. The combination of advanced compressors and turbines optimizes airflow and energy use, while FADEC provides precise engine control, contributing to the engine’s reliability and efficiency during long-haul operations. Overall, the CFM56-7B’s design advancements make it a highly efficient engine for commercial aviation, improving fuel economy, reducing noise, and meeting

environmental and operational requirements, as highlighted by industry sources such as Aircraft Commerce.

The CFM56-7B engine has become a reliable key asset in military applications, particularly for the United States Air Force (USAF), due to its high performance and versatility. According to CFM (2020, October 29), the USAF selected the CFM56 engines for their KC-135 aircraft re-engining program, citing "higher performance, lower life-cycle costs, lower noise, and easier support" as reasons for the choice. The USAF plans to further upgrade older aircraft with the CFM56-7B engine, which offers higher thrust, improved fuel efficiency, and meets environmental standards. Additionally, the CFM56-7B gearbox can handle high electrical power demands, and the engine can be installed without a thrust reverser to reduce weight. These upgrades will enhance the performance of older aircraft, extend their service life, and support the USAF’s Advanced Battle Management System (ABMS) development (CFM, 2020). The improved fuel efficiency and reduced environmental impact also make the CFM56-7B a sustainable option for the future. By integrating these engines into their fleet, the USAF ensures continued operational efficiency, reliability, and the capability to meet evolving military needs. The engine's ability to function without a thrust reverser also contributes to weight savings, further improving performance. In military applications, particularly in Boeing 737-based aircraft, the CFM56-7B engine has proven to be reliable and adaptable, cementing its role in the USAF fleet and showcasing its durability in various operational contexts (CFM, 2020).

While it’s true that the CFM56-7B shows superiority over its predecessors, the CFM company has recently developed its Leading Edge Aviation Propulsion (LEAP) engine*. This engine can support not only the Boeing 737 MAX aircraft but also the Airbus A320neo, and COMAC C919. It features larger fan diameters ranging from 69 inches to 78 inches. The engine is built on aerodynamics and materials technology to deliver enhanced propulsive and thermal efficiency, resulting in fuel savings of up to 20% (CFM, 2024). It also complies with the highest noise regulations, improving passenger comfort while decreasing noise disturbances for communities near airports. CFM's dedication to sustainability is evident in the LEAP engine’s ability to operate on blends containing 50% Sustainable Aviation Fuel (SAF), and its successful trials with 100% SAF further highlight its environmentally friendly features (CFM, 2024). To conclude, the LEAP engine not only builds on the successes of the CFM56-7B but also sets new standards in efficiency, sustainability, and performance in the aviation industry.

In conclusion, whilst the LEAP engine is far better than the CFM56-7B, its successful development would not have been possible if not for the groundwork that was laid by the CFM56-7B. As airlines increasingly focus on being both efficient and environmentally responsible, the journey from the CFM56-7B to the LEAP engine showcases exciting innovations in aviation. This evolution illustrates how the successes of the past not only shape but also inspire the advancements that will define the future of flight.

[References]

Aircraft Commerce. (2008, July). CFM56-7B series specifications. https://www.aircraft-commerce.com/wp-content/uploads/aircraft-commerce-docs/Aircraft%20guides/CFM56-7B/ISSUE58_CFM56_7B_SPECS.pdf

Aircraft Commerce. (2010, July). 737NG family & CFM56-7B specifications, fleet & developments. https://www.aircraft-commerce.com/wp-content/uploads/aircraft-commerce-docs/Aircraft%20guides/737NG-600-700-800-900/ISSUE70_737NG_SPECS.pdf

CFM International. (2018, April 20). CFM International issues new service bulletin to CFM56-7B operators. https://www.cfmaeroengines.com/press-articles/cfm-international-issues-new-service-bulletin-cfm56-7b-operators/

CFM International. (2020, October 29). CFM56-7B offers reliability, life extension for Boeing 707 platforms. https://www.cfmaeroengines.com/press-articles/cfm56-7b-offers-reliability-life-extension-for-boeing-707-platforms/

CFM International. (2024). CFM56 - CFM International jet engines. https://www.cfmaeroengines.com/engines/cfm56/

CFM. (2024, October 1). Technical manual index. https://www.cfmaeroengines.com/wp-content/uploads/2024/10/CFM56-Engine-Manuals-Index.pdf

CFM International. (2024). LEAP.

https://www.cfmaeroengines.com/leap/

GE Aviation. (2024). CFM LEAP. https://www.geaerospace.com/commercial/aircraft-engines/cfm-leap

Levingston, C. (2019, June 4). 1 billion flight hours: “World-class experience” builds 15,000th CFM56-7B engine. https://www.geaerospace.com/news/articles/manufacturing-paris-airshow-people-product/1-billion-flight-hours-world-class-experience

Monroe Aerospace. (2023, December 1). Low vs high bypass turbofan engines: What’s the difference? https://monroeaerospace.com/blog/low-vs-high-bypass-turbofan-engines-whats-the-difference/

Comments

Post a Comment

Popular posts from this blog

Personal Reflection

  Hello Professor Brad, I am Danial Amirul, a first-year Mechanical Engineering student who will be enrolling into your Critical Thinking and Communicating class, S20. I graduated from Temasek Polytechnic (TP) with a diploma in Aerospace Electronics, and have attained the Certificate of Recognition (COR) that is endorsed by the Civil Aviation Authority of Singapore (CAAS). In TP, I have attended a similar subject called Current Issues and Critical Thinking (CICT), thus, I feel that I will have an easier time understanding things taught in your class. I chose Mechanical Engineering due to my prior educational background and likeness for aircraft from a young age. I have always been fascinated by how such a huge and complex machine is trusted to transport people and goods across the globe. Throughout the years, from all the various class presentations, a communication weakness that I have identified about myself is that I have a lack of confidence during presentations. This would res...
Read more

The Beginning.

“Communication skills are an essential component in the education of engineering students to facilitate not just students’ education but also to prepare them for their future careers.” - Marc Riemer, Faculty of Engineering, Monash University (2007)     I chose this quote because I feel that this quote highlights the importance of communication, and why we have to do it effectively, especially in our careers. In the classroom, learning good communication skills would help students, like myself, to be able to present our ideas more effectively. In the workplace, strong communication skills would allow team members to work together, and ensure that everyone understands their role and what they are supposed to do to reach the desired outcome. To add to that, if a problem were to arise, good communication among team members would allow them to identify the problem and solve it as quickly as possible without having any time wasted. Furthermore, engineers with strong communication s...
Read more

Reader Response draft #1

The CFM56 is a family of high-bypass turbofan aircraft engines produced by CFM International, a 50/50 joint company between Safran Aircraft Engines and GE Aerospace (CFM International, 2024). As the widely known Airbus and Boeing companies continuously develop different aircraft models over the years, the CFM company would also have to address the needs and challenges of each plane model. The CFM company has produced several variants in its engine family to cater to the needs of such airplanes including the military. Each of the variants is a better, more updated version of its predecessor. According to the CFMI (2003, pg 26) training manual, the CFM56 variants include the CFM56-2 series, CFM56-3 series, CFM56-5A, 5B and 5C series, and the CFM56-7B series. A high-bypass turbofan engine has a large amount of air passing through the core of the engine instead of through the engine's combustion chamber, hence the name, high-bypass. This makes the engine more efficient than its low-byp...
Read more