After two deadly crashes in a five month span, the United States and several other countries have grounded all Boeing 737 Max aircraft pending further investigation.

As investigations mount, Boeing and the Federal Aviation Administration are pushing back against claims that the Boeing 737 Max was rushed through the standard certification process.

The New York Times reported that Boeing created the 737 Max to compete with Airbus and that engineers were asked to complete designs at twice the normal pace.

Boeing began developing plans for the 737 Max in 2012 and the first 737 Max 8 was manufactured in November 2015; its final FAA certification was completed on March 9, 2017.

Boeing's 737 Max aircraft is now the subject of multiple investigations after two fatal plane crashes killed 346 people in a span of five months. Earlier this month the United States and several other countries ordered that all 737 Max airplanes would be grounded until the aircraft's safety could be guaranteed.

As investigations and new reports begin to explore the crisis around the 737 Max, Boeing and the Federal Aviation Administration are pushing back against claims that the 737 Max was rushed through development and the federal certification process.

Lion Air Flight 610 crashed in the Java Sea on October 29th, killing all 189 passengers; Ethiopian Airlines Flight 302 crashed on March 10, killing all 157 people on board.

The New York Times reported Saturday that Boeing pushed to develop the 737 Max to compete with Airbus's A320neo plane. During spring 2011 Boeing was at risk of losing an exclusive 10-year relationship with American Airlines to Airbus. American was considering placing its largest aircraft order ever with Airbus, who had recently announced their fuel-efficient A320neo. American told Boeing it would need to move quickly to retain their business.

Boeing launched the Max program in 2011 and engineers were reportedly asked to complete technical drawings and designs at twice the standard pace. When staff members left the team, Boeing leveraged employees from other departments to ensure that the Max project stayed on schedule. According to the Times, employees felt the project was "hectic," but they were still confident the 737 Max was safe.

In a statement obtained by the Times, Boeing said development on the 737 Max began in 2011 and the first manufactured 737 Max was completed in November 2015. The 737 Max received its final FAA certification on March 9, 2017.

"A multiyear process could hardly be considered rushed," Boeing said in the statement to the Times.

Members of Congress criticized the Federal Aviation Administration's decision to allow outsourced inspectors in Boeing's certification process. Connecticut Sen. Richard Blumenthal said that the FAA left "the fox guarding the hen house," by giving Boeing too much control over the people responsible for quality control and safety.

In a statement obtained by the Wall Street Journal, the FAA said the use of delegation, or outsourcing, is standard practice. Boeing also said that the 737 Max met all the same FAA requirements as their other aircraft had. However, during a February 2018 earnings call, Boeing CEO Dennis Muilenburg reportedly told investors that the company was working on "streamlining certifications."

“FAA has never allowed companies to police themselves or self-certify their aircraft,” the agency said in their statement. “The use of delegation has been a vital part of our safety system since the 1920s, and without it, the success of our country’s aviation system likely would have been stifled.”

To help get the aircraft back in the air, Boeing plans to make a safety software that was previously optional on the 737 Max a standard feature. The software is called a "disagree light," and gives pilots additional information on the plane's pitch in midair. Boeing reportedly charged clients for the software — neither Lion Air Flight 610 nor Ethiopian Airlines flight 302 had access to the feature. Investigators are still determining the specifics of the two crashes, but reports suggest that both planes could have been forced into a dive due to automated software.