The chief of the Federal Aviation Administration expressed concern Wednesday that it took more than a year before his agency learned that Boeing disclosed it had a problematic cockpit warning alert in its 737 Max jetliners.
Non-functioning cockpit warning lights are one of the key issues being examined in the probes of two Max 8 crashes that killed everyone on board.
But even if it had reviewed the information sooner, the FAA deemed the warning indicator not to be critical to flight safety, said Acting Administrator Daniel Elwell. In fact, he said he didn't think the indicator would have saved either of the two 737 Max jetliners that crashed months apart from destruction. A total of 346 people died.
Elwell assured the aviation subcommittee of the House Transportation and Infrastructure Committee that the 737 Max, grounded worldwide after the accidents, won't fly again until it is deemed safe. He gave no timetable. He defended the FAA's decision to ground the jet only after other nations had already done so, saying the agency had no data at the time upon which to base such a decision.
Unlike other countries that reacted in the wake of the two crashes alone, Elwell said the FAA relies on a "risk-based, data-driven approach" in making such assessments. And a review of data from 737 Max flights in the U.S. didn't reveal any anomalies in the software-driven flight program that appears to have figured in the two crashes, called the Maneuvering Characteristics Augmentation System, or MCAS.
In both the October crash of a Lion Air flight over the Java Sea and in the March accident involving an Ethiopian Airlines 737 Max, pilots repeatedly wrestled with the MCAS system, pushing the plane's nose down and resisting to keep the jets airborne. The system was designed to compensate for the plane's heavier, repositioned engines that can make it tend to point higher in the air. Boeing is now redesigning the system.
The 737 Max is equipped with two sensors that tell pilots whether the plane is pointed too high. But the MCAS system had been designed to automatically kick in when it received readings from only one even if it might disagree with the other. Boeing offered airlines an optional warning indicator to alert pilots when the two sensors' readings disagreed with each other, which could have given them notice of an issue with MCAS.
In 2017, Boeing engineers discovered the software that activated the alert didn't always work, but the issue wasn't considered important enough to merit a fix right away. The software problem wasn't disclosed to the FAA until after the Lion Air crash, which Elwell sees as a problem.
"I am concerned it took a year and we're looking into that and we're going to fix that," Elwell said.
But Elwell said the indicator was meant more to help pilots note any systems that needed repair on the plane, not as a dire warning about a malfunction that could imperil MCAS. Elwell said the warning light was "advisory," meaning there are no actions a pilot needs to take if it illuminates.
"Once we learned the light is not operable, we made the decision it is not a safety-critical display," he said.
The MCAS system overall, however, is critical to safety, he said. Elwell, who flew as a pilot in the Air Force and for airlines, said he's disturbed that Boeing didn't tell pilots about MCAS through their flight manuals.
"As a pilot, when I first heard about this, I thought there should have been more in the manual."
This article originally appeared on USA TODAY: FAA chief defends grounding Boeing 737 Max later than other nations, worries problem took a year to discover