The United States Federal Aviation Administration, which has been investigating Boeing’s grounded 737 Max in the wake of two crashes caused by malfunctions of its onboard systems, has discovered another, unrelated safety flaw.
Reuters was first to report the news, with its sources indicating that the new safety issue was discovered in simulator tests last week, and now Boeing faces increased delays – which may include the potential need for hardware fixes – before it’s able to regain certification for airworthiness of its 737 Max.
The FAA originally grounded the jets in March following investigations into an Ethopian Airlines crash on March 10 that killed 157 people and a Lion Air crash off the coast of Indonesia on October 29 that resulted in 189 deaths.
The focus of investigations has centered on a software program intended to compensate for new engines, but when paired with a faulty sensor, made it difficult for pilots to control.
On Wednesday, the FAA said it is not ready to allow the Boeing 737 Max aircraft back into service and it was investigating previously discovered and other potential risks.
Here’s the official FAA statement about it, which is vague on details, not surprisingly:
The Federal Aviation Administration (FAA) is following a thorough process, not a prescribed timeline, for returning the Boeing 737 Max to passenger service. The FAA will lift the aircraft’s prohibition order when we deem it is safe to do so. We continue to evaluate Boeing’s software modifications to the MCAS and we are still developing necessary training requirements. We also are responding to recommendations received from the Technical Advisory Board. The TAB is an independent review panel we have asked to review our work regarding 737 Max return to service. On the most recent issue, the FAA’s process is designed to discover and highlight potential risks. The FAA recently found a potential risk that Boeing must mitigate.
FAA pilots have uncovered a data processing issue impacting their ability to perform the procedure for counteracting “runaway stabiliser.”
This is the method by which pilots are supposed to respond to erroneous activation of the MCAS, which is the software that activated prior to two Boeing 737 MAX crashes.
Here’s what a source tells FlightGlobal:
“During simulator testing last week at Boeing, FAA test pilots discovered an issue that affected their ability to quickly and easily follow the required recovery procedures for runaway stabiliser trim. The issue was traced to how data is being processed by the flight computer.”
The MAX is the newest iteration of the 737 design, which was originally introduced in the 1960s. Boeing found itself in hot water following two deadly crashes involving the planes, however, which claimed a total of 346 lives.
Both the Lion Air crash in Indonesia and the Ethiopian Airlines crash were linked to the improper work of the Maneuvering Characteristics Augmentation System (MCAS), designed to prevent the plane from stalling, which instead sent the aircraft into nosedive.
Boeing later admitted that an ‘optional’ set of indicators it sells separately could potentially have helped prevent the tragedies, but only 20 percent of the MAX jets had them. The company also did not alert FAA about the issue until the first crash, even though it allegedly knew about it since 2017, when the MAX line was introduced.
All 737 MAX aircraft were grounded internationally three months ago, and Boeing was required to upgrade its onboard software a present a new system to safety watchdogs for re-certification.