4月底，波音公司与CFM International为一架搭载了改造版LEAP-1B发动机的747飞机进行了首飞测试，测试地点位于加利福尼亚州维克多维尔的通用航空飞行测试中心。

这是一个为期两年的项目，预计在2016年完成LEAP发动机的认证，并在2017年推出波音737 MAX。本次进行的飞行测试是这一项目的里程碑。据称，在5.5小时的首飞测试中，LEAP（尖端航空推进）发动机已在多个海拔高度上成功完成多项航空力学测试。

CFM的首席试飞驾驶员Steven Crane表示：“这些发动机所体现出的技术成熟度很少能在新产品身上看到。” CFM是一家由Snecma和通用公司以各占50%股权的结构建立的合资企业。

LEAP-1B是波音737 MAX系列的专用发动机，同时也是“CFM史上最为详尽的地面与飞行测试认证项目。”第一台LEAP-1B发动机于2014年6月13日开始地面测试，比2011年项目开始时所设定的测试日程早了3天。波音商用飞机部门737 MAX项目副总裁兼总经理Keith Leverkuhn表示，737 MAX的燃油效率将会比当今效率最高的下一代737高出14%，比首批进入市场的下一代737高出20%。

整个5月都排满了测试项目，待测内容包括发动机的运行、失速裕度、性能、排放和声学测试等。此外，测试中还将验证一些发动机中的高级技术，包括编织碳纤维复合材料风扇、双环预混(TAPS)燃烧室、高压涡轮中的陶瓷矩阵复合材料侧支索、以及低压涡轮中的铝化钛叶片。

“LEAP发动机已经以相当出色的表现，通过了一次异常严格的地面和飞行测试项目，”CFM执行副总裁的Allen Paxson表示。“所有发动机都配上了大量仪器设备，许多还进行了人为的损坏，以测试其在最严苛的环境下表现出的性能和耐久性。我们已成功完成几个重要的认证测试，包括结冰、鸟群吸入、大型鸟类吸入，甚至还有风扇叶片脱落测试。这台发动机通过了全部测试，结果也符合预期要求。”

至今为止，搭载LEAP-1B的737 MAX已获得来自全球57家客户的2724份订单。整个项目涵盖了所有三种型号的LEAP发动机，地面与CFM飞行测试共使用28台，飞机制造商测试共使用32台。LEAP-1A是空客A320neo的选配发动机，而LEAP-1C则是COMAC C919机型的专用发动机。

三年来，这些发动机累计完成近4万次循环测试，已为正式服役做好准备。LEAP发动机开始服役时，已研发出60款不同型号航空发动机的CFM，在航空领域的经验将超过十五年。

CFM于2008年正式发布了LEAP发动机——这是该公司近40年来研发的首台全新的中心线发动机(centerlineengine)。该发动机是为了超越CFM56系列而设计的，无论是在燃油效率、还是在排放和噪音的减少方面，新款发动机都实现了两位数的增长，而且还能维持前者的耐久性和较低的拥有成本。

2011年，波音将LEAP-1B选为其全新737 MAX机型的专用发动机，继续延长与CFM超过30年的合作关系。CFM是自1984年737 Classic上市以来，737系列的独家发动机供应商。

LEAP for Boeing 737 MAX makes first flight

At the end of April, Boeing and CFM International initiated flight testing of the LEAP-1B engine on a modified 747 flying testbed at GE Aviation Flight Test Operations in Victorville, CA.

The flight testing is a major milestone in a two-year program that will culminate in engine certification in 2016 and delivery of the first Boeing 737 MAX in 2017. The LEAP (leading edge aviation propulsion) engine is said to have performed well and completed multiple aeromechanical test points at various altitudes during the 5.5 h first flight.

According to Chief Test Pilot Steven Crane, CFM, "These engines are demonstrating a maturity that you don't always see in new products." CFM is a 50/50 joint venture between Snecma and GE.

The LEAP-1B engine is the exclusive powerplant for the Boeing 737 MAX family and is part of “the most extensive ground and flight test certification program in CFM's history.” The first LEAP-1B engine began ground testing on June 13, 2014, three days ahead of the schedule set when the program was launched in 2011. Keith Leverkuhn, Vice President and General Manager, 737 MAX program, Boeing Commercial Airplanes, says the 737 MAX is on track to deliver 14% more fuel efficiency than today's most efficient Next-Generation 737s and 20% more efficiency than the first Next-Generation 737s to enter service.

Throughout May, the flight test program will consist of a comprehensive test schedule that will gauge engine operability, stall margin, performance, emissions, and acoustics. It also will further validate 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 titanium aluminide blades in the low-pressure turbine.

"The LEAP engine has been doing incredibly well throughout a very rigorous ground and flight test program," said Allen Paxson, CFM Executive Vice President. "All of these engines are heavily instrumented, many of them deliberately deteriorated, to calibrate performance and durability in the most extreme conditions. We have successfully completed several major certification tests, including icing, flocking bird ingestion, large-bird ingestion, and even a fan blade-out test. We have passed them all and the results are right in line with what we predicted and where we wanted this engine to be."

To date, the LEAP-1B-powered 737 MAX has accumulated 2724 orders from 57 customers worldwide. The total program encompassing all three LEAP engine variants includes 28 ground and CFM flight test engines, along with a total of 32 flight test engines for the aircraft manufacturers. The LEAP-1A is an option for the Airbus A320neo and the LEAP-1C is the only Western powerplant option for the COMAC C919.

Over a three-year span, these engines will accumulate approximately 40,000 engine cycles leading up to entry into service. By the time this engine enters service, CFM will have simulated more than 15 years of airline service with 60 different engine builds.

CFM officially launched the LEAP engine, which is the company's first all-new centerline engine in nearly 40 years, in 2008. The engine was being designed to bring double-digit improvements in fuel efficiency, emissions and noise, while maintaining the reliability and low cost of ownership of its predecessor, the CFM56 engine family.

In 2011, Boeing selected the LEAP-1B as the sole powerplant for its new 737 MAX, extending a more than 30-year relationship. CFM has been the only engine provider for the 737 aircraft family since the 737 Classic entered service in 1984.