737 Max

CFM International has completed the design freeze for the Leap-1B engine, the sole powerplant for the Boeing 737 MAX aeroplane that is scheduled to enter service in 2017.

The development represents a milestone for the Leap-1B programme and paves way for the first full engine testing in mid-2014.

CFM International stated that this development was the point where the engine configuration is set, allowing the company to finalise and publish detailed engine design drawings, which it plans do over the next six months.

Leap-1B engine is manufactured by CFM International, a 50/50 joint venture of Snecma and GE Aircraft Engines.

GE Aviation Leap programme manager Gareth Richards said that achieving design freeze was a significant step in the programme.

"All of our testing and design work leading to this moment demonstrates that we are on track to meet all of our programme commitments," Richards added.

Snecma Leap programme manager Francois Bastin said: "The extensive component tests we have completed so far, including both the core engine and full fan module testing currently underway, indicate that we are on track to deliver world-class fuel efficiency for the 737 MAX, along with the world-class reliability and durability that we established with the CFM56 engine family."

The parts manufacturing for the Leap-1B engine is expected to accelerate by the end of this year, which will lead to build-up of the first engine in early 2014.

The Leap-1B is on schedule for CFM flight testing in 2015 and engine certification in 2016; there are 12 Leap-1B certification engine builds scheduled over the next three years.

With customised turbo-machinery and installation to meet the requirements of the 737 MAX aircraft, the Leap-1B engine is the outcome of a CFM’s six-year collaboration effort with Boeing.

"All of our testing and design work leading to this moment demonstrates that we are on track to meet all of our programme commitments."

The design freeze for the Leap-1A and Leap-1C engines was completed in June 2012.

Currently, the first full Leap engine, the Leap-1A, is being constructed and is due to commence ground testing in the middle of this year.

Over the past five years, CFM has been conducting component and rig tests on Leap hardware, and the programme is now moving into an exhaustive engine ground test phase.

CFM will have 28 certification engine builds and 30 flight test engines across the three Leap engine models.

According to CFM, the advanced Leap engine will offer a 15% improvement in specific fuel consumption (SFC) compared with the existing CFM56 engines as well as an equivalent reduction in carbon emissions, nitrogen oxides (NOx) emissions.

Image: The completetion of design freeze for the Leap-1B engine paves way for the first full engine testing in mid-2014. Photo: courtesy of Boeing.

Defence Technology