For a little over a year, Florida-based Spirit Airlines was evaluating if it should buy Airbus SE A320neo or Boeing 737 Max planes. Then the Boeing crisis struck late last year, with one 737 Max crashing in October 2018, and the second Max crashing in March 2019.

As a result, the entire global fleet of 737 Max planes was grounded in March, and seven months and counting with no clarity on when the aircraft would return to the air, flight regulators in Indonesia are about to release a formal report on Friday that will detail how major mechanical and design problems with a flight control system were responsible for the Lion Air 737 Max crash in October. 

With too many mechanical uncertainties swirling around the 737 Max, now in a full-blown crisis for Boeing, there's an even more troubling trend that could doom Boeing even further: this involves Spirit Airlines ditching a potential Boeing order for Airbus. 

Spirit expects to add 100 new A320neo planes to its fleet by 2021, reported Bloomberg. 

The low-cost air carrier operates only Airbus 320 family models, is expected to have a fleet of 145 planes by year-end and 193 by 4Q21. Spirit could fly as many as 300 320s in the coming years.

Like Spirit, many other carriers have given the 737 Max second thoughts since the crisis began about one year ago.  

Airbus is on track this year, for the first time since 2011, to outpace Boeing in annual deliveries amid the 737 Max groundings. 

Airbus expects to deliver 571 jets in the first nine months of 2019.

Delivers for A321neo jumped 57% for the first nine months, hitting a four-month high in September.

Boeing has since halted deliveries and cut production by 20% to 42 a month. 

The 737 Max crisis has allowed Airbus to take in a flood of new orders, including ones from US carriers. 

Boeing is dealing with the company's largest crisis in 100 years.

The backlashing against Boeing is only in the beginning innings. Boeing's credibility died in 2019, and it's only a matter of time before other US carriers gravitate to Airbus.