Audio reveals pilots confronting Boeing after deadly crashes

© AP A Boeing 737 MAX 8, being built for American Airlines, is partially obscured by the engine wash as it takes-off on a test flight Wednesday, May 8, 2019, in Renton, Wash. The Boeing 737 Max 8s have been grounded following deadly crashes in Indonesia and Ethiopia. Analysts expect that idling the Max 8s, a fuel-efficient update of Boeing's popular 737, will crimp growth plans in the near future. (AP Photo/Elaine Thompson) Arlington, Va. — CBS News has obtained audio from the American Airlines pilots' union confronting Boeing about new features to the 737 Max that may have been factors in two deadly crashes. Frustration boiled over during the tense meeting in November 2018, less than a month after the first Max crashed, and four months before the second crash.

"We flat out deserve to know what is on our airplanes," one pilot is heard saying. 

"I don't disagree," the official said.

Last October, Lion Air flight 610 went down off the coast of Indonesia killing 189 people. Investigators believe a faulty sensor triggered the plane's MCAS anti-stall system that repeatedly pushed the plane down.

The pilots at the meeting were angry that system was not disclosed to them until after the first crash.

"These guys didn't even know the damn system was on the airplane — nor did anybody else," one pilot said.

Related Slideshow: Boeing's 737 MAX (provided by Photo Services)

The European Union along with other nations have grounded all Boeing 737 Max 8 and Max 9 jets, after the crash of a Max 8 being flown by Ethiopian Airlines that killed 157 people on March 10. We take a look at the creation of Boeing's newest plane.

(Pictured) An American Airlines Boeing 737 Max 8 prepares to land at the Miami International Airport on March 12, 2019 in Miami, Florida.

In 2011, Southwest Airlines committed to buying 150 of Boeing's newest plane, the Boeing 737 MAX. The first Boeing 737 MAX was delivered to Southwest in August of 2017. As of 2019, they had 34 in its fleet.

Boeing vice president Mike Sinnett, who does not appear to know he was being recorded, claimed what happened to Lion Air was once-in-a-lifetime type scenario.

"I don't know that understanding this system would've changed the outcome on this. In a million miles, you're going to maybe fly this airplane, maybe once you're going to see this, ever. So we try not to overload the crews with information that's unnecessary so they actually know the information we believe is important," the official said.

The pilots in the room were not satisfied with that answer. "We're the last line of defense to being in that smoking hole. And we need the knowledge," one pilot said.

Boeing told the pilots it would make software changes, perhaps in as little as six weeks, but didn't want to hurry it.

"We want to make sure we're fixing the right things," the official said. "That's the important thing. To make sure we're fixing the right things. We don't want to rush and do a c****y job of fixing the right things, and we also don't want to fix the wrong things."

That fix was still in development when the second 737 Max crashed in March, leading to the worldwide grounding of the plane. The existence of the audio was first reported by the Dallas Morning News.