LEAP-1B

Visão geral

The LEAP-1B é a única planta motriz para a família Boeing 737 MAX, compartilhando a mesma tecnologia de núcleo avançada que o LEAP-1A but adapted to the 737's dimensional constraints. A famosa baixa distância ao solo do 737 — um legado do design original dos anos 1960 with its underwing main landing gear — forced CFM engineers to reduce the fan diameter to 69.4 inches (1.763 m) compared to 78 inches on the LEAP-1A, and to position the engine accessories to the top and sides of the nacelle rather than beneath it. The resulting razão de bypass of 9:1 is lower than the LEAP-1A's 11:1, yet the LEAP-1B ainda oferece aproximadamente 14% melhor consumo de combustível que o CFM56-7B que substitui.

The LEAP-1B shares the same CMC turbina de alta pressão shrouds, tecidas em 3D pás de fan compostas (18 blades), TAPS II combustor, and fabricada por manufatura aditiva fuel nozzles as its sibling variants. Boeing selected LEAP-1B como motor exclusivo para o 737 MAX, unlike the A320neo which offers a choice between LEAP-1A and the Pratt & Whitney GTF. This fonte única arrangement created significant operational risk when the 737 MAX was grounded worldwide from March 2019 to November 2020 após dois acidentes fatais ligados ao sistema de controle de voo MCAS — a software and design issue unrelated to the engines.

Especificações técnicas

Variantes

LEAP-1B variants cover the full 737 MAX thrust range. The LEAP-1B27 (27,000 lbf) powers the 737 MAX 7, while the LEAP-1B28 (28,000 lbf) is the standard for the 737 MAX 8 and LEAP-1B28E1 covers the MAX 8-200 high-density variant. The LEAP-1B28BBJ1 serves the Business Jet derivative. The LEAP-1B28/B1 (up to 29,317 lbf) powers the larger 737 MAX 9 and MAX 10. All variants share common line replaceable units (LRUs) and maintenance procedures, minimizing fleet complexity for 737 MAX operators.

Aplicações em aeronaves

• Boeing 737 MAX 7: LEAP-1B27 (27,000 lbf) — menor variante MAX
• Boeing 737 MAX 8: LEAP-1B28 (28,000 lbf) — variante MAX de maior volume
• Boeing 737 MAX 9: LEAP-1B28B1 (29,317 lbf) — MAX alongado
• Boeing 737 MAX 10: LEAP-1B28B1 (29,317 lbf) — o 737 mais longo já construído

História do desenvolvimento

Development of the LEAP-1B began formally when Boeing launched the 737 MAX program in August 2011. The first LEAP-1B engine run took place in June 2014, with FAA certification achieved in May 2016. The 737 MAX 8 entrou em serviço comercial with Malindo Air in May 2017. Following the two fatal crashes (Lion Air 610 in October 2018 and Ethiopian Airlines 302 in March 2019), the 737 MAX fleet was grounded globally. LEAP-1B engines accumulated significant time during the 20-month grounding with engines stored on the aircraft or in warehouses, requiring re-certification of airworthiness upon return to service. The MAX returned to service in the US in December 2020. By 2024, LEAP-1B had powered the 737 MAX family to over 30 million horas de voo. Introduction of the 737 MAX 10 in 2023 represented the highest-thrust application of the LEAP-1B platform.