WASHINGTON — Late on Tuesday, U.S. legislators decided against adding a delay to an annual defense bill that would impose a higher safety level for contemporary cockpit alerts on two new Boeing 737 MAX variants.

The American aircraft manufacturer has been trying to persuade lawmakers for months to extend the deadline that applies to its MAX 7 and MAX 10 aircraft and was imposed by Congress in 2020 after two 737 MAX crashes that left 346 people dead in Indonesia and Ethiopia. 

Congress approved the standards for contemporary cockpit alerts as part of certification reform following the two catastrophic 737 MAX crashes in 2018 and 2019 that resulted in the aircraft's 20-month grounding. That would be a major setback for the MAX 7 and MAX 10 programs.

The Maneuvering Characteristics Augmentation System (MCAS) developed by Boeing was determined as the cause of both crashes. MCAS was meant to pretend the flight characteristisc of the previous generation Boeing 737 NGs. During MAX flight tests, Boeing discovered that the position and larger size of the engines tended to push the nose up during certain maneuvers. Engineers decided to use MCAS to eliminate it, since major structural redesign would have been extremely expensive and time-consuming. Boeing's goal was to have the MAX certified as another 737 version, which would appeal to airlines with the reduced cost of pilot training. The Federal Aviation Administration (FAA) approved Boeing's request to remove a description of MCAS from the aircraft manual, leaving pilots unaware of the system when the airplane entered service in 2017.

In both 737 MAX crashes, MCAS repeatedly pushed down the aircraft's nose down due to the faulty angle of attack data from one of the sensors located on the left and right front of the fuselage.

According to the bill offered to Congress, all aircraft must have upgraded and common cockpit alerting systems in order to receive Federal Aviation Administration (FAA) certification. This requirement might imperil the MAX 7 and 10's future or result in substantial delays in the deployment of the new aircraft.