May 15 (UPI) -- House lawmakers on Wednesday attempted to get to the bottom of Boeing's troubled 737 Max airliners, asking aviation leaders about an update on the grounded fleet and about how the planes were certified to fly years ago.
The House transportation and infrastructure committee questioned acting Federal Aviation Administration chief Dan Elwell and National Transportation Safety Board Chairman Robert Sumwalt about the planes, which have been barred from flight for two months.
The fleet was grounded worldwide in March after the second of two deadly crashes within a six-month time span. Nearly 350 people died in the crashes, which investigators have said were influenced by an automated flight system on the airliner. Boeing has said a fix is coming soon, but the planes won't be back in the air for several more weeks at the earliest.
"We shouldn't be here today," committee Chairman Peter DeFazio, D-Ore., said.
Lawmakers want to hear about how the FAA certified the 737 Max 8 and why Boeing was given so much authority to regulate its safety. The jetliner was one of its most popular model before the crashes in Indonesia and Ethiopia.
"Boeing continues to support the ongoing accident investigations and is committed to working closely with members of Congress, their staff and relevant officials," Boeing spokesman Charles Bickers told the panel. "Safety is a top priority when we design, build, deliver and maintain Boeing aircraft."
Elwell refuted reports that the FAA wasn't directly involved in approving the plane's flight-control system. He said the agency participated in test flights of the same system believed to have factored in both crashes.
"As our work continues, I offer this assurance: In the U.S., the 737 Max will return to service only when the FAA's analysis of the facts and technical data indicate that it is safe to do so," Elwell said.
Reports have also said Boeing failed to identify the stall-prevention feature as a critical system that could result in a catastrophic failure. Such a designation would've mandated more scrutiny of the system. The investigation results so far, however, have not suggested Boeing intentionally misled the FAA.
Panel Chairman Rick Larsen, D-Wash., said Wednesday he's still seeking answers from the FAA.
"The committee's investigation is just getting started, and it will take some time to get answers, but one thing is clear right now: The FAA has a credibility problem," he said.
The Max 8 variant was first conceived in 2006 as the newest version of Boeing's best-selling 737 and was developed on a six-year schedule. The 737 Max fleet officially launched in August 2011 and boasted a slate of safety and technological upgrades over older 737s and competitor models like the Airbus A320. Boeing changed the design of the ordinary 737 to include "winglets" to save fuel and reduce carbon emissions. It also added LED lighting for landing, taxi and runway maneuvers. The newer Max planes also increased the flight range by hundreds of miles.
The Max 8, the model involved in the recent crashes, made its maiden flight in January 2016, and the Max 9 about a year later. The Max 8 was first to market and saw its initial delivery in mid-2017.
Boeing said it's received about 5,000 orders for 737 Max aircraft and has so far delivered nearly 400. Boeing says nearly 70 carriers worldwide -- including American Airlines, Air Canada, Air Europa, Air China, Korean Airlines and Virgin Australia -- fly the 737 Max 8. The scrutiny over their grounding, however, has led some carriers to reassess prior orders.
Investigators have said both crashes involved the plane's anti-stall Maneuvering Characteristics Augmentation System. A fix, as well as plans to retrain pilots, was unveiled in March and tested by airlines last month. American and Southwest, the only U.S. carriers flying the Max 8, have said they won't return to the air until at least this summer. Boeing said last month it's taken a $1 billion hit due to the global grounding.
Also last month, Southwest said it wasn't told by Boeing that certain safety warning lights in the Max 8 cockpit had been disabled, because they were not standard equipment. The Dallas-based carrier said Boeing didn't acknowledge that distinction until after the first crash last October.
Boeing said this month it had been aware the safety feature -- which alerts pilots if an angle-of-attack sensor isn't working -- was only operable on 20 percent of the fleet, and only for carriers that bought it as an optional feature.