Approvals from other global aviation safety regulators are expected shortly after the U.S. Federal Aviation Administration's decision.
Here is what industry experts, customers and rivals are saying about the move:
AIRBUS CHIEF EXECUTIVE OFFICER GUILLAUME FAURY
"I will not say anything because we are a competitor."
AIR LINE PILOTS ASSOCIATION (ALPA)
"ALPA believes that the engineering fixes to the flight-critical aircraft systems are sound and will be an effective component that leads to the safe return to service of the 737 MAX."
CONSULTING FIRM AERODYNAMIC ADVISORY MANAGING DIRECTOR KEVIN MICHAELS
"This is great news but ... It will take several years (for the 737 MAX supply chain) to get back to full production, may be as many as three years."
"When 737 MAX gets back to full production, it will probably be more in the 40s per month rather than the 50s per month. And Boeing lost a thousand of their orders for the 737 MAX over this crisis as well."
"We are probably headed for a world where it is not going to be a 50-50 duopoly with Airbus anymore. It is going to be more like 58% or 60% versus 40% to 42% in Airbus' favor."
AFA-CWA INTERNATIONAL PRESIDENT SARA NELSON, who represents flight attendants at nearly 20 airlines
"This day is the result of the persistence of engineers and manufacturing workers at Boeing. But this day is also a reminder of why this plane has not flown for two years."
BOEING CEO DAVID CALHOUN
"We have implemented a series of meaningful changes to strengthen the safety practices and culture of our company."
"We have also undertaken a thorough assessment to ensure that our systems meet all regulatory standards."
"Every next plane we deliver is an opportunity to rebuild our brand and regain trust."
BRAZILIAN AVIATION REGULATOR ANAC
ANAC said it is taking final steps that would allow the 737 MAX to return to operation in Latin America's largest market.
CITI ANALYST JONATHAN RAVIV
"The 737 MAX is now a demand problem where Boeing has to find airlines willing to take airplanes."
"Before COVID-19, it was a supply problem where airlines were desperate to take as many airplanes as possible. So we don't see the inventories clearing or production rates normalizing until 2023."
FAMILIES OF SOME VICTIMS KILLED IN FATAL 737 MAX CRASHES
"In their mission to unground the plane, Boeing's and the FAA's focal point has been MCAS. They ignored all the signalized engineering design flaws," said Canada-based Paul Njoroge, who lost his entire family in one of the accidents.
"You would rather walk before you ever consider boarding a B737 MAX plane."
Michael Stumo, father of 24-year-old Samya Rose Stumo of Massachusetts who was killed in a MAX crash, said, "The aggressive secrecy of the FAA means we cannot believe the Boeing 737 MAX is safe."
"We have repeatedly asked for the technical descriptions of the alleged fixes, the test protocols and results and the safety assessments. But the FAA won't release them and Boeing won't consent to their release."
TEAL GROUP ANALYST RICHARD ABOULAFIA
"The market really won't need new-build planes for a few years, since there are 387 737 MAX's waiting to return to service, and 450 already-built 737 MAX's waiting to be delivered."
"Boeing needs to re-start production at some low level. But they won't get above 20 per month for at least two years, and they won't get to where they wanted to be - over 50 per month -until the middle of the decade."
TRANSPORT CANADA
"Transport Canada safety experts continue their independent validation process to determine whether to approve the proposed changes to the aircraft. We expect this process to conclude very soon."
(Reporting by Ankit Ajmera in Bengaluru; Editing by Bernard Orr, Shinjini Ganguli and Maju Samuel)
