Boeing has once again been put in the hot seat after it was revealed that both the Federal Aviation Administration (FAA) and Southwest Airlines were not informed before the Lion Air crash that the 737 Max models' safety feature was turned off.

In a statement sent to CNBC, Southwest said, "Upon delivery (prior to the Lion Air event), the AOA Disagree lights were depicted to us by Boeing as operable on all MAX aircraft, regardless of the selection of optional AOA Indicators on the Primary Flight Display (PFD)."

Southwest further explained that Boeing notified the airlines that the AOA Disagree Lights or the safety alert feature on the 737 Max jets were turned off after the Lion Air jet crashed shortly after takeoff from Jakarta, Indonesia in October.

Likewise, industry officials and U.S. government sources told The Wall Street Journal that FAA supervisors and safety inspectors did not know about the issue. The outlet further reported that the FAA mulled whether or not Southwest's entire Max fleet should be grounded until pilots received additional training.

To address the issue, Boeing said all airlines availing the 737 Max jets "will have the AOA disagree alert as standard and have the option to include the AOA indicator at no cost." The American jet maker added that all Max models will receive the changes.

Last week, Boeing released its quarterly annual results, indicating that it lost $1 billion following the grounding of its 737 Max jets. The said models were grounded after the Lion Air crash and the Ethiopian Airlines crash in March.

According to Business Insider, Boeing cannot estimate how much more it will lose as its 737 Max jets have yet to be certified again before taking flight. A joint international panel has also decided to investigate how the airliners were certified before the deadly crashes.

Boeing's Q1 2019 results also revealed that the company's profits dropped by 21 percent in comparison to results from the same period last year. The jet maker announced that new guidance will be released at a later date due to uncertainty with its 737 Max jets.

Earlier this month, CNN reported that a couple of airlines have completely stopped ordering Boeing 737 Max models. Only 10 Max jets were ordered in January and February and no airliner placed orders all throughout March.

Indonesia's Garuda canceled 50 Boeing 737 Max jets but the company still has 5,000 orders of the popular models. It is unclear when the jets will fly again as investigators pursue probes on the two crashes that took the lives of 346 people onboard.