A US Senate committee plans a hearing on 27 March on aviation safety after two fatal Boeing 737 Max 8 aircraft crashes since October, and said it will also schedule a hearing with Boeing and other manufacturers, officials said on Wednesday.

The hearing on federal oversight on commercial aviation by the Senate commerce subcommittee on aviation and space will include the US Federal Aviation Administration’s (FAA) acting administrator, Dan Elwell, National Transportation Safety Board chairman, Robert Sumwalt, and transportation department inspector general, Calvin Scovel.

The panel plans to call Boeing and other aviation manufacturers to testify amid a scramble to discover what caused the crashes of an Ethiopian Airlines flight last week and a Lion Air flight in Indonesia last October.

The news came as it was announced by the FAA on Wednesday afternoon that Boeing is developing a service bulletin instructing airlines to install new flight control computer operational program software in the now grounded Boeing 737 Max aircraft.

The agency said in a bulletin to foreign regulators and airlines that its “ongoing review of this software installation and training is an agency priority, as will be the rollout of any software, training, or other measures”.

Boeing previously said it planned a software upgrade. The FAA and other regulators grounded the aircraft type after two fatal crashes since October.

The US grounded the planes last Thursday, following on the heels of other countries.

The panel, chaired by the Texas senator Ted Cruz, a Republican, said: “In light of the recent tragedy in Ethiopia and the subsequent grounding of the Boeing 737 Max aircraft, this hearing will examine challenges to the state of commercial aviation safety, including any specific concerns highlighted by recent accidents.”

A second hearing on aviation safety is planned “in the near future to hear from industry stakeholders that would include Boeing, other aviation manufacturers, airline pilots, and other stakeholders”, the committee said.

Boeing Company, the world’s biggest planemaker, faces growing obstacles to returning its grounded 737 Max fleet to the skies, while details emerged of potential similarities between the two crashes.

Meanwhile, later on Wednesday, Boeing announced that it had delayed, by three months, its first un-crewed flight to the International Space Station under Nasa’s human spaceflight program, and pushed its crewed flight until November, industry sources said on Wednesday, Reuters reported.

The news agency reported last month that Nasa has warned Boeing and rival contractor SpaceX of design and safety concerns the companies need to address before flying humans to space.