CBS News is reporting that members of the American Airlines pilots’ union confronted Boeing in late 2018 about features on the 737 MAX aircraft that have been implicated in two fatal crashes. Audio has been released of an exchange between pilots and Boeing executives, recorded in November 2018—less than a month after the Indonesia Lion Air Flight 610, which killed all 189 people on board, and just four months before Ethiopian Airlines Flight 302, which killed 157 people.

Pilot: “We flat-out deserve to know what is on our airplanes.”

Boeing official: “I don’t disagree.”

Pilots expressed anger that a faulty sensor system on the 737 MAX was not communicated to them until after the first deadly accident, and pushed Boeing to work urgently on fixing the issue. The 737 MAX is still grounded, and multiple lawsuits and investigations into the crashes are underway.