The USA has ordered a review to determine how Boeing's 737 Max aircraft got its licence to fly.
New evidence from experts suggest that there were 'clear similarities' between the crash in Ethiopia earlier this month which killed 157 people and a crash in Indonesia in October which left 189 dead.
The USA's transport secretary has asked the US inspector general to audit the aircraft's certification process.
Elaine Chao the review will help "assist the Federal Aviation Administration in ensuring that its safety procedures are implemented effectively".
Last week Boeing grounded its entire global fleet of 737 Max aircraft.

Quakes rock Venezuela, killing at least 32 and injuring hundreds
Trump asks Congress for more funds to fight Iran, defying rebuke on war powers
Magnitude 6.9 quake strikes Japan's northeast, no tsunami warning
US, Iran at odds on nuclear inspections, frozen assets in deal to end war
Oman establishes temporary shipping corridor through Strait of Hormuz
