Boeing is developing a service bulletin for 737 Max operators for the installation of new flight computer software, says the US Federal Aviation Administration.
The airframer has also developed flight crew training in relation to the software, adds the FAA in an update on the 737 Max grounding today.
It is not immediately clear when the service bulletin will be issued. A Boeing spokesperson referred FlightGlobal to a 11 March statement on plans to deploy a software improvement for the 737 Max in the "coming weeks".
The development of the software enhancement followed the October 2018 crash of a Lion Air 737 Max 8 which has been linked to a system new to the 737 Max, called the Manoeuvring Characteristics Augmentation System (MCAS). Similarities have been drawn between the Lion Air crash and the 10 March crash of an Ethiopian Airlines 737 Max 8.
"The FAA’s ongoing review of this software installation and training is an agency priority, as will be the roll-out of any software, training, or other measures to operators of the 737 Max," says the FAA. The agency had earlier said it will mandate the software improvement through an airworthiness directive no later than April.
The FAA ordered the grounding of the 737 Max on 13 March, becoming the last major regulator to take action following a string of groundings worldwide by other aviation authorities in the wake of the Ethiopian crash. The US Department of Transportation has requested its inspector general to audit the certification process of the 737 Max 8.
US carriers operated 74 737 Max aircraft as of 11 March. Globally, 59 carriers operated 387 737 Max aircraft, says the FAA.
Separately, a panel of US lawmakers will hold a hearing on aviation safety on 27 March, in response to the 737 Max grounding. National Transportation Safety Board chairman Robert Sumwalt, Department of Transportation inspector general Calvin Scovell and FAA acting administrator Daniel Elwell will testify at the hearing held by the US Senate subcommitee on aviation and space.
The committee intends to hold a second hearing "in the near future" that will call upon Boeing and other aviation manufacturers, it says.