Questions about the process – and whether the Federal Aviation Administration granted Boeing too much oversight – have arisen since a March 10 Ethiopian Airlines crash involving the 737 Max 8 plane that killed 157 people. That crash followed an Oct. 29 Boeing 737 Max 8 crash of Lion Air Flight 610 in Indonesia where 189 perished.
“Not only have the recent crashes shaken the confidence of the public, but the questions that have been raised in the aftermath about FAA’s oversight of aircraft manufacturers, the certification process for planes and the close relationship between industry and regulators, threaten to erode trust in the entire system," said Texas GOP Sen. Ted Cruz, who chaired the Aviation and Space Subcommittee hearing.
Elwell said the safety certification process “requires the open and transparent exchange of information" between regulators and the industry because it's crucial the FAA hear from airline manufacturers to identify hazards and come up with solutions.
"Decades of experience have proven that this approach yields knowledge that we would not otherwise obtain," he told the committee, noting that safety rules for large aircraft like Boeing's 737 have been amended more than 130 times since 1964.
Boeing first applied for 737 Max 8 certification in 2012 and the process took about five years to complete, Elwell said. The FAA was "fully involved" in the process, participating in 133 of the 297 flight tests, some of which included reviews of the aircraft’s Maneuvering Characteristics Augmentation System (MCAS) that investigators are looking at as a possible link between the two crashes.
The changes – previewed at the company's Renton, Washington, facilities – focus on a flight-control system designed to keep the plane's nose from pitching up, which figured in one crash and is suspected of playing a role in a second.
The proposals come as Boeing faces not only pressure as flight cancellations mount because of grounded jets, but scrutiny from Congress.
The two crashes killed a combined 346 passengers and prompted a number of countries to ground the aircraft used at their airports. The U.S. was the last major government to take such action.
Here are five things to know about Wednesday's hearing:
No one from Boeing testified
The hearing did not feature anyone from Boeing, even though the plane crashes involving the 737 Max 8 are prompting the congressional review.
Company officials instead are expected to testify at a later hearing with other industry officials. Even so, Boeing President and CEO Dennis Muilenburg has been leading a public relations campaign to try to assure the public his company is on top of any problems.
Pilots from five airlines, including the three U.S. carriers that flew the Max jets before they were grounded worldwide, tested upgrades to the flight-control system over the weekend at Boeing’s facility outside Seattle, the aircraft manufacturer confirmed.
Boeing also hosted more than 200 airline pilots, technicians and regulators in an informational session Wednesday that’s among the initial steps in its attempt to get the Max planes flying again.
Aviation authorities have noted clear similarities between that airplane’s movements and the path taken by Ethiopian Airlines Flight 302, which crashed March 10 just outside the capital city of Addis Ababa and took the lives of the 157 passengers and crew on board.
FAA: Not grounding planes based on 'data'
The U.S. was the last major country to allow the 737 Max 8 plane to keep flying after the second crash, despite criticism the aircraft should have been grounded earlier.
Elwell told senators he couldn't explain why other countries decided to ground their planes sooner but "our decision was based on data."
Elwell said initial flight path data they received on March 11, the day after the Ethiopian Airlines crash, was not conclusive. It was not until two days later, after officials saw more "refined" data about the plane's flight path, that they decide to ground the planes.
Pressed by Sen. Richard Blumenthal, D-Conn., about conversations he had with President Donald Trump about whether to ground the planes, Elwell declined to disclose those talks.
Cruz ran a spirited presidential campaign in 2016, when he came in second behind Donald Trump for the GOP nomination. Cruz was chided for his eagerness to support Trump following a bitter, insult-filled contest between the two candidates.