Boeing is stretching out the timeline for patching anti-stall software under scrutiny in two crashes of its best-selling 737 MAX jetliners, promising to take as much time as necessary to get it right.
The Federal Aviation Administration now says it expects to receive the final draft of Chicago-based Boeing’s software fix “over the coming weeks.” The U.S. agency joined its international peers in grounding the aircraft, the latest version of one of the world’s most widely flown planes, in mid-March after flight data from a downed Ethiopian Airlines plane showed choppy ascents and descents during takeoff, mirroring those before a Lion Air crash in Indonesia on Oct. 29.
“Safety is our first priority, and we will take a thorough and methodical approach to the development and testing of the update,” a Boeing spokesman said in a statement on Tuesday. Time for additional work was needed to ensure the plane-maker addressed all “pertinent issues,” the FAA said.
The delay on a system the agency originally expected to approve by April follows a Senate hearing into the original certification of the aircraft, where lawmakers questioned the FAA’s relationship with the plane-maker. The accidents have snarled airline schedules for the foreseeable future and prompted Transportation Secretary Elaine Chao to seek a review of the jetliner’s initial approval for commercial flights.
In the Indonesian crash, a malfunctioning sensor on a 737-8 MAX fed incorrect data on the airliner’s ascent vector to a computer system that attempted to lower the angle to avoid a stall, officials said. That prompted a struggle between computer software known as the Maneuvering Characteristics Augmentation System, or MCAS, and the pilot, who ultimately lost control of the aircraft.
All 189 people aboard were killed. The fact that Boeing hadn’t yet completed a software patch that the FAA mandated afterward was part of what prompted the high level of concern when the Ethiopian Airlines crash outside the capital of Addis Ababa killed all 157 passengers and crew.
“We need to understand exactly what happened, both in these specific crashes and with the certification process for the MAX aircraft so that we can take action to keep something like these tragic crashes from occurring again,” Sen. Ted Cruz, R-Texas, said during a hearing by the chamber’s aviation panel, which he leads. “We need to look at the aviation space more broadly and identify where we can and should make improvements.”
The 737 MAX, the latest version of a plane flown since 1967, underwent less-rigorous scrutiny beforehand than a totally new model would have, and the FAA relied heavily on inspections done by Boeing employees themselves under a system that delegates some duties to non-agency employees and organizations, including companies, that have particular expertise.
Seventy-nine organizations are authorized to handle such duties, acting administrator Randy Elwell told the panel, though the FAA retains the right to intervene directly at any time. Its personnel are always involved in level-of-safety determinations and establishment of rules for special situations, he added.
Evaluation of the MAX, from Boeing’s first permit application to final certification in March 2017, took five years and included 297 flight tests, some of which involved the anti-stall software linked to the first crash and under examination in the second, Elwell said.
Boeing has garnered more than 4,600 orders for the single-aisle jetliner, though just 67 of the aircraft are flown in the U.S. and fewer than 400 worldwide. The plane-maker only began delivering the plane in 2017 and was working to ramp production up to 57 a month, which would have netted a potential $30 billion in sales this year, prior to the Ethiopian crash.
