Boeing 737 MAX
The first 737 MAX 8 plane undergoes final assembly at Boeing’s Renton plant in 2015. (Boeing Photo)

In the wake of two catastrophic crashes that may have had a common cause, Transportation Secretary Elaine Chao today opened the way for an audit of the process that led the Federal Aviation Administration to certify Boeing’s 737 MAX 8 jets in 2017.

Because of the similarities between the two crashes, 737 MAX jets have been grounded worldwide. Boeing and the FAA are reportedly facing multiple investigations, including the audit announced today.

Chao formally requested the audit in a referral memo to the department’s Office of Inspector General.

The audit is meant to “help inform the department’s decision making and the public’s understanding, and to assist the FAA in ensuring that its safety procedures are implemented effectively,” Chao wrote. It will be part of a continuing review of factors related to aviation certification, she said.

In a tweet, Boeing said it would “fully cooperate” with the audit.

The audit is likely to address claims that the FAA put too much reliance on Boeing’s own analysis if safety issues surrounding the 737 MAX during its years-long development.

The MAX is the latest version of Boeing’s workhorse single-aisle passenger airplane, with engines that are larger and more fuel-efficient than the previous-generation 737. The heft of the engines changed the aerodynamic characteristics of the 737.

To minimize the need for pilot retraining, Boeing developed an automatic control system, known as the Maneuvering Characteristics Augmentation System or MCAS, which was designed to keep the plane from stalling if it encountered extreme conditions.

Investigators say the MCAS appears to have played a role in last October’s crash of a nearly new Lion Air 737 MAX 8 jet in Indonesia, which killed 189 people. And preliminary reports suggest that an Ethiopian Airlines 737-8 traced a similar flight profile before it crashed on March 10 in Ethiopia, killing 157.

In both cases, pilots reported flight control problems just minutes after takeoff, and soon afterward, each plane went into a catastrophic nose dive.

In the Lion Air case, investigators surmise that the MCAS system received spurious data from a single sensor that monitored the wings’ angle of attack. Boeing says pilots can follow a procedure to disengage the MCAS in the event of a malfunction, but the Lion Air pilots didn’t follow that procedure.

This week, reports emerged that readings extracted from the flight data recorder on the Ethiopian plane pointed to a similar angle-of-attack issue.

Also this week, reports in The Seattle Times and the Wall Street Journal raised questions about the procedures that the FAA and Boeing followed during development of the 737 MAX. To expedite that development effort, Boeing conducted its own safety analysis for the MAX and submitted it to the FAA.

The Seattle Times quoted sources as saying that the initial analysis downplayed the scope and persistence of the MCAS system, as well as the need for additional pilot training. Speaking on condition of anonymity, a former FAA safety engineer said there was “constant pressure” to review Boeing’s documents quickly.

The Wall Street Journal said the Transportation Department will look into whether unwarranted shortcuts were taken during the certification process. A separate grand jury investigation was being directed by the Justice Department, the Journal reported, and congressional hearings are a near-certainty.

Boeing says it will soon roll out a software update for the 737 MAX that limits operation of the MCAS, and issue new guidance for pilot training as well. But the fact that multiple investigations are in the works suggests that the software fix won’t immediately fix Boeing’s image problem.

Even if the FAA clears the 737 MAX for flight, regulators in Canada and other countries outside the U.S. say they won’t take the FAA’s word but will conduct their own review. Air Canada said it plans to keep the jets grounded until at least July 1.

Rep. Adam Smith, D-Wash., whose district includes the Boeing plant in Renton where the 737 MAX is built, said today that he worries about the plane’s reliance on automatic control systems like the MCAS.

“It’s like when you call information, it’s great to have all these different menus, but you always want to be able to press zero and talk to a human,” Smith said during an appearance at a quantum computing summit at the University of Washington. “When you’re setting up these machines, all else fails, you’ve got to be able to push a button and just operate the damn thing.”

Like what you're reading? Subscribe to GeekWire's free newsletters to catch every headline

Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.