1 year after the Ethiopian Air Flight 302 crash, questions remain as to when Boeing's 737 Max will fly again

One year ago -- the crash that led to one of the longest aircraft groundings in history. Ethiopian Airlines Flight 302 crashed near Addis Ababa airport just six minutes after takeoff, killing all on board.

It was the second crash involving a Boeing 737 Max within five months. In October, Lion Air Flight 610 was airborne for only 13 minutes before it plunged into the Java Sea off the coast of Indonesia. A total of 346 people died in both accidents.

The similarities between the two crashes raised questions about the safety of the Boeing 737 Max. Countries around the world began grounding the plane, and, on March 13, 2019, the Federal Aviation Administration (FAA) grounded the Max in the United States.

Almost a year after the grounding, 400 brand new Max planes continue to sit in storage like untouched artifacts and Boeing and the FAA are still resolving issues with the plane.

WHAT HAPPENED?

Investigators found that both crashes were tied to a software called the Maneuvering Characteristics Augmentation System (MCAS). MCAS was designed to help stabilize the 737 Max after heavier, re-positioned engines placed on the aircraft caused the plane's nose to point too far upwards in certain circumstances.

In both crashes, incorrect data from a faulty sensor caused MCAS to misfire, forcing the plane to nose down repeatedly even as pilots struggled to regain control and gain altitude. MCAS was not mentioned in the pilot manual.

The National Transportation Safety Board (NTSB) found that the pilots were bombarded with multiple alarms and alerts in the cockpit before the planes crashed. The blaring alarms likely caused further confusion and made an already stressful situation worse, according to the NTSB.

“It's very understandable why they were overwhelmed, ABC News Contributor Col. Steve Ganyard said, "but that part of it gets covered when you do the basic emergency procedures.”

In December, House Democrats released a Federal Aviation Administration (FAA) risk report which showed the potential of more than 15 fatal crashes over the life of the Max fleet -- about 45 years -- if no change was made to MCAS.

DID BOEING PLACE PROFIT OVER SAFETY?

Lawmakers from both sides of the aisle have expressed concerns that Boeing sacrificed safety to remain competitive.

“There was tremendous financial pressure on Boeing and subsequently the 737 MAX program to compete with Airbus’ A320neo aircraft,” the House Committee on Transportation and Infrastructure found in its initial report following its investigation into the Max. “Among other things, this pressure resulted in extensive efforts to cut costs, maintain the 737 MAX program schedule, and not slow down the 737 MAX production line.”

House Transportation and Infrastructure Committee chairman Rep. Peter DeFazio, D-Ore told ABC News in October that the committee received "report after report about production pressures" inside Boeing, as part of its investigation.

"I fear that profit took precedence and put pressure on the whole organization all the way down," DeFazio said at the time.

Boeing has repeatedly said that safety is and always has been it's highest priority.

IS THE AIRCRAFT CERTIFICATION SYSTEM BROKEN?

Currently under the Organization Designation Authorization (ODA) program mandated by Congress, some of the aircraft certification process is delegated to manufacturers like Boeing. Critics of the ODA program said it was this delegation that created a conflict of interest.

The House committee's report went as far as to say the FAA “failed” in its oversight of Boeing.

The FAA said its a learning agency and that they welcome the scrutiny.

"We are confident that our openness to observations and recommendations will further bolster aviation safety worldwide," the FAA said in response to the house committee's findings.

In December, FAA Administrator Stephen Dickson told lawmakers he believes the aircraft certification system is not broken, but he did concede that there is room for improvement.

Within a few weeks, committee chairs on the House Transportation and Infrastructure plan to introduce legislation to address what they consider "failures" in the aircraft certification process.

WILL ANYONE BE HELD RESPONSIBLE?

The two fatal 737 MAX crashes have sparked multiple investigations from U.S. agencies, including the Department of Justice and the Securities and Exchange Commission.

The company is also facing lawsuits from family members of those lost in both the Lion Air and Ethiopian Air crashes. Boeing created a fund to provide $50 million in immediate assistance to families of the victims and pledged a total of $100 million to "address family and community needs of those affected by the tragedies."

The Max production line is currently shut down and almost three months ago Boeing fired then CEO Dennis Muilenberg.

Muilenburg repeatedly expressed intentions to stay until the Max was ungrounded.

“These two accidents happened on my watch,” Muilenberg said in a Senate hearing on the crashes last year. “I feel responsible to see this through."

WHEN WILL THE MAX FLY AGAIN?

Boeing is still working with the FAA to get its once fastest selling jet back in the sky. Boeing decided to not just rewrite the software for the MCAS flight control system, but the entire flight computer software.

The fixes they are sorting out now are unrelated to what investigators say brought the two jetliners down. Over the past month alone, problems have emerged with wiring in the plane’s tail and an indicator light.

In the next few weeks Boeing is planning to conduct a certification flight test with FAA pilots -- a key step in the eventual ungrounding of the Max.

The company is sticking by its estimate of the Max returning to service by the end of the summer, but arguably the toughest task will be winning back the public’s trust.

“The 737 MAX, or whatever it’s called in the future, will be a great airplane, but it will take time. People are not going to be happy getting on the MAX branded aircraft, ” ABC News Contributor Col. Steve Ganyard said.