Elwell outlined efforts by Boeing and regulators to boost pilots' awareness of procedures for preventing planes from overcorrecting, but acknowledged under questioning that the information initially sent to pilots could have more heavily emphasized the system.
In each case, spurious data apparently caused an automatic flight control system known as the Maneuvering Characteristics Augmentation System, or MCAS, to push the plane into a catastrophic dive.
Nadia Milleron, whose daughter, Samya Stumo, was on the Ethiopian Airlines plane, was in the audience at Wednesday's hearing. There's no indication the issues identified by the unions led to incidents.
"Next week they're bringing together the heads of civil aviation authorities - their FAA equivalents if you will from other countries - they're bringing them into the U.S.to walk through and talk through the steps they've taken to date". The agency wanted to transition its workforce of engineers, pilots and inspectors who assess new aircraft designs to focus on only the highest risk issues and on auditing the work of companies.
Across Capitol Hill, the Senate Commerce Committee held a relatively placid hearing for Dickson, the nominee to replace Elwell, FAA's acting administrator since January 2018.
House Aviation subcommittee Chairman Rick Larsen opened the hearing with Elwell by declaring that, "The FAA has a credibility problem".
Boeing has been criticized for not disclosing how the MCAS anti-stall system worked - a move that allowed the company to avoid costly retraining.
It was believed to have played a role in the erratic flying and fatal plunge of an Indonesian Lion Air flight in October and the similar crash of an Ethiopian Airlines flight in March, which prompted the aircraft to be grounded worldwide.
However, he conceded pilots could have been better informed about the automated flight-control system implicated in both crashes. Neither crew managed to counteract the system and each eventually crashed.
Larsen added a note of economic urgency to the grounding of the Max, Boeing's best-selling plane and one that is built in his home state of Washington.
The FAA is overseeing Boeing's MCAS upgrade as both it and Boeing face federal investigations, including by the US Department of Justice. The jetliner was one of its most popular model before the crashes in Indonesia and Ethiopia. The MCAS does the opposite - it creates the hazardous condition and induces the pilot error.
"Whatever corrective actions need to be taken or process changes need to be put in place, I can guarantee you that those will be accomplished", Dickson said. Such a designation would've mandated more scrutiny of the system. The agency declined to say what steps, if any, it took in 2017 to address the specific allegations because of the numerous investigations now underway into the plane.
And another News investigation, for instance, last month found that multiple pilots had shared safety concerns with federal authorities about the Boeing plane ahead of the deadly crashes, with one captain calling the plane's flight manual "inadequate and nearly criminally insufficient".
Industry analysts predicted that the American jet maker's journey towards getting a second certification for its 737 Max models will be longer and more arduous, especially with the release of the recorded meeting.