The US Department of Transportation has requested its inspector general to carry out an audit of the certification process of the Boeing 737 Max 8, less than a week after US regulators grounded the aircraft.
In a memorandum to DOT inspector general Calvin Scovell III, US transportation secretary Elaine Chao says: "This is to confirm my request that the Office of Inspector General proceed with an audit to compile an objective and detailed factual history of the activities that resulted in the certification of the Boeing 737 Max 8 aircraft."
US regulators ordered the grounding of the 737 Max on 13 March, following the 10 March crash of an Ethiopian Airlines 737 Max 8 outside Addis Ababa that killed all 157 people onboard. The US Federal Aviation Administration was the last major regulator to ground the aircraft, with agencies in China, Europe and the UK taking action ahead of US regulators.
While investigations into the Ethiopian crash are ongoing, there are reports of similarities between the incident and the October 2018 crash of a Lion Air 737 Max 8. A preliminary probe into the Lion Air crash has pointed to problems related to the Manoeuvring Characteristics Augmentation System, which is new to the 737 Max.
Questions have since been raised over Boeing's influence over the 737 Max certification process, with a Seattle Times report highlighting the US FAA's delegation of certification tasks to Boeing for the aircraft.