As of July 30, 2019 the Boeing 737 Max is still pretty much out of service. The replacement for the Boeing 737 was grounded in March of 2019 by regulators world wide after it’s second major mishap.
The original Boeing 737 began life in 1967, a medium sized and rugged passenger jet airplane suited for short and medium length flights, and powerful enough for takeoff on shorter runways.
Southwest Airlines was built on the original Boeing 737, and has delayed retirement of the old birds to deal with problems with the new 737 Max. Since its inception, Southwest Airlines has flown more than 700 of the older 737 in their fleet.
When Boeing made the decision to build a replacement for the 737, they faced some design challenges because the 737 had a lot of power for a smaller large jet. Boeing chose to keep the original flight controls in an updated jet by designing a fly-by-wire system that mimicked the older 737 operations to fly the newer 737 Max aircraft.
Boeing assured flight engineers, pilots, regulators and pilot training authorities that pilots familiar with the operating characteristics of the older 737 would be comfortable and competent with the new 737 Max controls. Most authorities agreed, and minimal pilot retraining was demanded for pilots with certification in the old 737 to transition to the 737 Max.
Fly-by-wire advocates are certain that the flaws that might or might not have contributed to the mishaps will be resolved, and the 737 Max will return to service. While some authorities have questioned the capabilities and characteristics of the fly-by-wire computer programs, other sources in the news have indicated that the mishaps may have been caused by bird strikes and poor maintenance, not purely software related.