American Airlines just completed the Boeing 737 Max's first passenger flight in the US since March 2019

• American Airlines flew the first scheduled passenger flight in 21 months of the Boeing 737 Max in the US on Tuesday from Miami to New York.
• The uneventful flight marked the beginning of a new chapter for the aircraft that aims to restore confidence from the traveling public.
• Airlines like American are eager to get the plane flying to take advantage of its economics and get the grounding behind them.
• The aircraft was grounded for 20 months following two fatal crashes that took the lives of 346 passengers.

The Boeing 737 Max saga is finally over for American Airlines as the aircraft's first flight with paying passengers just landed safely at New York's LaGuardia Airport after a 3-hour flight from Miami.

American flight 718, a likely homage to one of New York's area codes, departed Miami onboard just on a routine flight up the East Coast with just 83 passengers, including American Airlines President Robert Isom, on Tuesday. The aircraft quickly climbed to 39,000 feet while hugging the coast, Flightradar 24 data shows, and settled in for the familiar yet monumental journey that would represent a second chance to the ill-fated aircraft.

It was one of the 11 daily flights American would operate between the two cities but arguably the most-watched flight of the day as the first one carrying paying passengers on the jet in the US since March 2019. The two-year-old aircraft operating the flight was delivered to American in May 2018, according to Planespotters.net, but has sat idle on the ground longer than it's been flying, enduring a 20-month grounding alongside 24 compatriots.

The weeks leading up to this first flight saw American eagerly work to return its Max aircraft to flying service, starting with implementing the required fixes mandated by the Federal Aviation Administration. Once its first few aircraft were in compliance, American began demonstration flights with employees and media, including Business Insider senior reporter David Slotnick.

It's the day that American has been waiting for since March 2019, but the Max's story began long before that with a phone call from then-American Airlines CEO Gerard Arpey to Boeing back in 2011. Arpey had pressured Boeing to produce a new fuel-efficient aircraft to rival the next-generation A320neo aircraft being produced by Airbus, which American was considering purchasing at the time.

American was placing a massive order for hundreds of new planes and Boeing was at risk to miss out if it didn't act quickly. The manufacturer was considering a clean-slate aircraft but American had forced its hand in pulling the trigger on a re-engined version of the popular 737 Next Generation, and the result was the Boeing 737 Max we know today.

"American is pleased to be the first airline to commit to Boeing's new 737 family offering, which is expected to provide a new level of economic efficiency and operational performance, pending final confirmation of the program by Boeing," the airline said in a statement, committing to the Max before it was known as the Max.

As Boeing soon found, however, developing the new jet wasn't as simple as giving it new, fuel-efficient engines as the aircraft's design needed to be adjusted. The new placement of the engines caused the plane to pitch up and fly differently than the current-generation 737s, prompting Boeing to install a quasi-autopilot system known as Maneuvering Characteristics Augmentation System to angle the plane down, unbeknownst to the pilots.

It was important that the Max flew just like its predecessor so pilots could fly both interchangeably with very little additional training. This was a key selling feature of the aircraft as it could keep training costs down for airlines.

An airline like American could train its pilots on the Boeing 737 using its existing training scheme and only require pilots to undergo minimal computer-based training to fly the Max at limited additional cost to the airline. It's not uncommon as Airbus has a similar setup for its Airbus A320 and A320neo family aircraft since the cockpits are nearly identical.

But the system ended up working against Boeing as sensor failures inadvertently activated and crashed two airliners carrying a total of 346 people. Boeing spent over a year working on fixes before the Federal Aviation Administration was satisfied enough to begin test flights in late September.

FAA Administrator Steve Dickson, a former airline pilot, was at the helm for one of them to personally vouch for the aircraft's safety. His agency had come under scrutiny for not properly regulating Boeing, mishandling the certification process for the 737 Max, and more recently, mishandling the recertification process, as a US Senate report found.

Read more: The 16 most outrageous things Boeing employees said about the company, 737 Max program, and each other in released internal emails

Building back the Max in the US

American is the first US airline to resume service with what is arguably the most infamous aircraft of the modern era, rushing to launch the aircraft in 2020 ahead of its competitors. Brazil's Gol Linhas Aéreas was the first airline to resume flying the Max, operating the first flight on December 9, followed by Aeromexico on December 29.

United Airlines won't be flying the aircraft for another month, planning to fly the Max from Houston and Denver starting February 11, 2021. Southwest Airlines, while maintaining the largest Boeing 737 Max fleet before the pandemic, hasn't yet announced a start date or loaded the aircraft into its schedule, the most recent Cirium data shows.

Alaska Airlines has a tentative start date of March 1, 2021, for the aircraft where it will fly routes across the West Coast. The first model is set to arrive at Alaska in January, after which the airline has promised extensive proving runs of over 50 hours across 19,000 miles.

Richard Aboulafia, vice president of analysis at Teal Group, told Business Insider that there are two likely reasons for American's haste in restoring the Max to service: fuel prices and seasonality. The aircraft has economic benefits that airlines can't afford to pass up and the Max can hedge against rising fuel prices thanks to its fuel efficiency.

"There is a concern that fuel prices are nudging upwards again, and might go higher again with the recovery," Aboulafia said.

American is also basing the aircraft in Miami, which has experienced a surge of travelers looking to escape the hardest-hit cities of the pandemic. Having the Max can help increase margins on routes to South Florida, and other popular locales like St. Thomas and St. Croix in the US Virgin Islands where American plans to fly the jet come January.

All four US airlines flying the Boeing 737 Max, however, have vowed flexibility for passengers who prefer not to fly on the aircraft. Passengers finding themselves on the aircraft can make free changes to other aircraft.

The successful first flight begins the long road to restoring consumer confidence in the jet. While some view the aircraft as the "single most scrutinized jet in history," as Aboulafia said, others are actively avoiding it as the Max has had staying power in the minds of the traveling public unlike any other grounded aircraft in recent years.

American will fly the plane exclusively between New York and Miami until January 5, 2021, when more routes will see the plane. And the Max name isn't keeping many away as the return flight from New York to Miami is reportedly "booked solid."