Transcript for Bombshell audio recording surfaces involving Boeing and pilots
tonight to the bombshell audio recording involving pilots actually warning Boeing, confronting the company about problems with its 737 max jets. The warnings came after the first crash, but before the second one. ABC's senior transportation correspondent David Kerley tonight with the audio. Reporter: We are hearing tonight the heated conversation just weeks after this first 737 max crash in Indonesia. We flat out deserve to know what is on our airplanes. I don disagree. Reporter: Union reps for American airline pilots in a tense November meeting with Boeing's top engineer about that new flight control system in the max. These guys didn't even know the damn system was on the airplane. Nor did anyone else. Reporter: It's called mcas and can force the nose down repeatedly. The pilots pressing for action, Boeing replying it was starting work on a software fix. The worst thing that can ever happen is a tragedy like this, and the even worse thing would be another one. Reporter: Another one did happen, a little more than three months later in Ethiopia. In both crashes, nearly 350 killed. With hundreds of max jets still grounded, members of congress demanded to know today, how did the FAA approve the system? Did it let Boeing drive the process? It wasn't even in the manual that this automated system existed. Wasn't in the manual? How can you have a system critical safety system certified? Our risk-based data-driven systems approach has led for to the U.S. Safest system in history. Let's bring in David Kerley with us live tonight. You've been following this all along, and we know there's a software fix from Boeing to fix this problem, it is coming, but it still has about been approved? Reporter: Not yet, in fact, the FAA administrator says he expects Boeing to submit that fix in the coming week, but he says it will not be approved until the FAA is certain that the max is safe. Boeing says it's working with regulators and customers around the world to get the 737 back in the air. David? David Kerley on this again tonight. David, thank you.
This transcript has been automatically generated and may not be 100% accurate.