Boeing 737MAX

The 737  is a low profile aircraft. By design the 737 can be loaded and unloaded without the use of a jet bridge. The 737 first flew in 1967 as a short haul supplement to the three engine 727. The 737 maintained the 707 cockpit and fuselage design. The 100 and 200 series 737 used a low by-pass JT8D engine.    The 737 would become Boeings most popular platform and with continued development of the 300/400/500 series, the 737 would take on a new look sporting the CFM56-3 engines. Because of its low profile design, the inlet on the CFM56 had a flat lower section to prevent ground contact.  Boeing continued to increase the capacity and range of the 737 with the design of the 600/700/800/900 Next Gen (NG) variants using the CFM56-7s.  With improvements in engine design, capacity, efficiency and profitability,  it would appear the 737 would have maxed out with the  (NG) variants and the Extended Range (ER) version.  But in 2011, Boeing announced the newest member of the 737 family, the 737MAX. The MAX was a 737 on the outside but anything but a 737 in design and flight characteristics.  

The MAX  would be fitted with the CFM LEAP.  The LEAP engine would require more clearance than the previous engines.  In my opinion, the 757 should have been the answer to the Airbus A320NEO.  But that would not be the case.  

The the 757 was taken out of production in part due to the competition of the 737NG and ER variants.  So not only was the 757 up against the 737, but also the Airbus A320. 

Due to the low ground clearance and larger engines, the LEAP engines had to positioned forward and upward as compared to the CFM56 series engines.

The positioning of the engines caused some aerodynamic changes in the flight characteristics  of the MAX.

Boeing wanted to make the 737Max handle like all previous variants of the 737 so pilots would be able to transition the Max without additional training.

Introduce the MCAS (Maneuvering Characteristics Augmentation System)

The MCAS receives information from the Angle of Attack (AoA) indicators to make the necessary corrections. Problem, Boeing only linked the MCAS to one AoA indicator.  Nearly every system on modern aircraft have redundant systems so as to prevent these types of accidents.  The big question is why? Why did Boeing only link MCAS to one AoA? 

As pilots transitioned to the Max, they had no idea there was a system on the Max called MCAS.  It was only after the Lion Air crash on 11/10/2018 that Boeing reviled the system.  

 While looking for a new single isle to compete with the Airbus A320Neo (New Engine Operation) Boeing turned its most profitable and popular design into a huge profit loss and loss of confidence in leadership over night.