The Federal Aviation Administration is facing political opposition to its handling of concerns about the Boeing 737 Max, with several lawmakers urging a grounding of the type.
Boeing, meanwhile, insists the 737 Max is safe, even as civil aviation authorities elsewhere have ordered the 737 Max grounded.
"I write to ask that all Boeing 737 Max 8 series aircraft be grounded until their safe use has been confirmed," California Democratic senator Dianne Feinstein stated in an 11 March letter to FAA acting administrator Daniel Elwell.
"Continuing to fly an airplane that has been involved in two fatal crashes within just six months presents an unnecessary, potentially life-threatening risk to the traveling public," Feinstein adds.
"The FAA [and] the airline industry must act quickly [and] decisively to protect American travellers, pilots [and] flight attendants," Richard Blumenthal, a Democratic senator from Connecticut who also sits on the commerce, science and transportation committee, tweeted the same day. "All Boeing 737 Max 8s should be grounded until American [travellers] can be assured that these planes are safe."
Some Republican lawmakers echoed such calls.
"Out of an abundance of caution for the flying public, the [FAA] should ground the 737 Max 8 until we investigate the causes of recent crashes and ensure the plane’s airworthiness," Utah Republican senator Mitt Romney tweeted on 12 March.
President Donald Trump also entered the fray, though he did not address the FAA's response to the crash involving an Ethiopian Airlines 737 Max 8 on 10 March.
"Airplanes are becoming far too complex to fly," Trump tweeted on 12 March. "Pilots are no longer needed, but rather computer scientists from MIT."
"I don’t want Albert Einstein to be my pilot. I want great flying professionals that are allowed to easily and quickly take control of a plane!" his tweets add.
The FAA on 11 March issued a notice saying the agency was not ready to ground the 737 Max as a response to the deadly crash of Ethiopian flight 302 near Addis Ababa. The agency said it lacked sufficient evidence for such a move, adding that it is investigating and will respond appropriately.
Numerous other aviation authorities and airlines have made the opposite decision, grounding the aircraft. Those include aviation agencies in Australia, China, Indonesia, Singapore and the UK. Airlines like Cayman Airways, Aerolineas Argentinas, Aeromexico, Comair, Ethiopian, Gol, Norwegian and Eastar Jet have also grounded their 737 Max fleets.
No US or Canadian airlines have grounded their 737 Max. The type's operators in those countries include Air Canada, American Airlines, Southwest Airlines and United Airlines.
"We are confident in the safety of the 737 Max and in the work of the men and women who design and build it," Boeing chief executive Dennis Muilenburg wrote in an 11 March letter to all staff.