As we’ve discussed before on this blog, the Boeing 737 Max was grounded worldwide in March 2019. Two separate 737 Max crashes, one in Indonesia and the other in Ethiopia, killed a total of 346 people and put Boeing in crisis mode.
The probable cause of the crashes was a problem with the anti-stall software, a system called MCAS. In each crash, the MCAS apparently malfunctioned and perceived the nose of the plane to be too high. Even though the pilots could see that the MCAS was malfunctioning, they were unable to follow Boeing’s recovery procedure. The pilots lost control.
The software issue seems to have come with some design changes in the aircraft, and the FAA has been criticized for improperly vetting those design changes at the time. For one thing, the MCAS was never properly incorporated into the 737’s flight manuals.
The 737 Max saga has been long and drawn out, with Boeing repeatedly trying to get the plane re-approved for flight. In March, regulators discovered bundles of wires in the Max that were physically too close together. Although the chance of a problem seems remote, regulators insisted that Boeing address the problem because a short-circuit could prove catastrophic.
Now, however, the FAA has cleared Boeing to undertake certification flights, which will be led by FAA pilots. A leading Boeing test pilot will back up the FAA pilots. The testing is likely underway this week near Seattle, where the plane is built. The testing will take several days and will include:
- A variety of flight maneuvers
- Emergency procedures
These are meant to enable to FAA to determine whether the updated 737 Max meets its safety standards. However, completion of these certification flights does not mean the 737 Max will be quickly back in the air.
After the certification flights are complete, the FAA will spend around a week developing a report that details its findings. This could include any new problems the FAA identifies during the certification flights. If it does, Boeing will have to address those.
After the FAA’s report is in, Boeing is expected to submit materials to the agency including details on the new software, along with its design and how it was tested. The FAA and outside experts will review that submission, which could take additional weeks.
On top of that, the FAA and its international counterparts will need to determine if any new training should be required for 737 Max pilots. Only then will the FAA clear Boeing to actually install the software update in existing planes. After that, the planes will need to be brought out of storage, subjected to maintenance, and tested before they can fly again.