Boeing has released a number of design decisions for its upcoming 737 MAX airliner, which is scheduled to begin deliveries in 2017.
Like the rival Airbus A320neo, the 737 MAX is a new engine variant based on the current generation airframe. Boeing estimates the upgraded LEAP-1B engines and other changes will make the 737 MAX 10-12 per cent more fuel efficient than current 737s.
The design decisions announced yesterday include:
- Aft body aerodynamic improvements: The tail cone will be extended and the section above the elevator thickened to improve steadiness of air flow, eliminating the need for vortex generators on the tail and resulting in less drag.
- Engine installation: The new CFM International LEAP-1B engines will be integrated with the wing similar to the aerodynamic lines of the 787 Dreamliner engine with its wing. A new pylon and strut, along with a 20cm nose gear extension, will maintain similar ground clearance to today’s 737 while accommodating the larger engine fan. The nose gear door design is altered to fit with this revision.
- Flight control and system updates: The flight controls will include fly-by-wire spoilers, which will save weight by replacing a mechanical system. The MAX also will feature an electronic bleed air system, allowing for increased optimisation of the cabin pressurisation and ice protection systems, resulting in better fuel burn.
Boeing said other changes to the 737 MAX include strengthening the main landing gear, wing and fuselage to accommodate the increase in loads due to the larger engines. The company said it was also testing a possible revision to the wing tips.
Boeing expects to finalise the 737 MAX design by mid-2013. To date, it has taken more than 1000 orders for the aircraft from 16 customers.