In Boeing's latest challenge, regulators plan to inspect and determine individual approval for all the company's 737 Max planes before they are delivered to airlines, according to the Federal Aviation Administration.
The FAA detailed its intentions to inspect the Max jets, which have been grounded since March, in a Tuesday letter to the company, according to The Wall Street Journal.
"At a minimum," the FAA won’t approve Boeing's pre-delivery aircraft until the company’s "737 MAX compliance, design and production processes meet all regulatory standards," the letter reads.
Additionally, regulators in Europe and the Middle East will conduct independent reviews of Boeing's latest 777X aircraft, the Journal reported, citing people familiar with the matter.
The FAA also said it would be tougher in its reviews of the 777X.
"The 777X is something we will be scrutinizing more carefully,” FAA Administrator Steve Dickson told reporters last week, according to the Journal.
The decisions come after two of the 737 Max planes crashed within five months of each other, killing 346 people total and bringing nearly 150 lawsuits against the company by families of the deceased.
"We continue to work with the FAA on the safe return to service of the MAX fleet," Boeing said in a statement.
The FAA's top safety official, Ali Bahrami, wrote a note to Dickson earlier this month saying, "I would like to send a strong message to the 737 Max team to reassure them that safety, not Boeing’s schedule, is our top priority," according to the Journal.
Dickson similarly said in a Nov. 15 video memo to employees that "there is a lot of pressure to return this aircraft to service quickly." He added that workers should "take the time" necessary to "focus solely on safety," and the FAA completely controls the approval process.
Capt. Dennis Tajer, who flies 737s for American Airlines, told NPR that the company's reputation has "been shaken," adding, "Boeing is still an incredible company, but they horridly fouled up this aircraft."