(Data below as of October 2018) The aircraft involved in 2011 ’s Lion Air crash is in commission for 40 airlines internationally , with orders in place from a further 36 carriers . Billed as the “ short - haul aircraft of the future ” , the Boeing 737 Max is facing further scrutiny following the crash . Investigation found the Lion Air ' ’s airspeed indicators had previously malfunctioned . A stall - prevention system had also been replaced , which regulators and pilots claimed was not properly highlighted . Southwest Airlines currently operates the highest numbers of the aircraft , notable for its large size and fuel economy . United Airlines is among other major airlines using it .
The aircraft involved in 2011 ’s Lion Air crash is in commission for 40 airlines internationally , with orders in place from a further 36 carriers . Billed as the “ short - haul aircraft of the future ” , the Boeing 737 Max is facing further scrutiny following the crash . Investigation found the Lion Air ' ’s airspeed indicators had previously malfunctioned . A stall - prevention system had also been replaced , which regulators and pilots claimed was not properly highlighted . Southwest Airlines currently operates the highest numbers of the aircraft , notable for its large size and fuel economy . United Airlines is among other major airlines using it .