Several pilots in the U.S. repeatedly voiced safety concerns about the Boeing 737 Max 8 to federal authorities, months before Sunday’s deadly Ethiopian Airlines crash, The Dallas Morning News, a Texas-based daily newspaper reported.
The News said it has found five complaints about the Boeing model in a federal database where pilots can voluntarily report about aviation incidents without fear of repercussions.
The complaints are about the safety mechanism cited in preliminary reports about an October Boeing 737 Max 8 crash in Indonesia that killed 189, it said.
The disclosures found by The News reference problems with an autopilot system, and they all occurred during the ascent after takeoff. Many mentioned the plane suddenly nosing down.
According to it, U.S. records show that at least five complaints were lodged with federal authorities in recent months, with one captain even calling the flight manual “inadequate and almost criminally insufficient”.
Records show that a captain who flies the Max 8 complained in November that it was “unconscionable” that the company and federal authorities allowed pilots to fly the planes without adequate training or fully disclosing information about how its systems were different from those on previous 737 models.
The captain’s complaint was logged after the Federal Aviation Administration (FAA) released an emergency airworthiness directive about the Boeing 737 Max 8 in response to the crash of Lion Air Flight 610 in Indonesia.
An FAA spokesman said the reports were filed directly to the National Aeronautics and Space Administration, which serves as a neutral third party for reporting purposes.
Tuesday evening, the FAA issued a statement saying that the agency “continues to review extensively all available data and aggregate safety performance from operators and pilots of the Boeing 737 MAX.”
“Thus far, our review shows no systemic performance issues and provides no basis to order grounding the aircraft. Nor have other civil aviation authorities provided data to us that would warrant action,” the statement said.
The complaint from the captain who called into question the 737 Max 8’s flight manual ended: “The fact that this airplane requires such jury rigging to fly is a red flag. Now we know the systems employed are error-prone – even if the pilots aren’t sure what those systems are, what redundancies are in place and failure modes. I am left to wonder: what else don’t I know?”
The Maneuvering Characteristics Augmentation System, or MCAS, was included on the Max 8 model as a safety mechanism that would automatically correct for a plane entering a stall pattern. If the plane loses lift under its wings during takeoff and the nose begins to point far upward, the system kicks in and automatically pushes the nose down.
After the Lion Air crash, the FAA issued an airworthiness directive that said: “This condition, if not addressed, could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain.”
Officials have not yet determined what caused Ethiopian Airlines Flight 302 to nose-dive into the ground Sunday, but many experts have noted similarities between this week’s crash and the one in Indonesia.
U.S. political leaders are calling on the FAA to ground the Boeing 737 jetliner that has come under scrutiny after two crashes in five months that killed everyone on board each time.
However, FAA and at least 18 carriers, including American Airlines and Southwest Airlines, the two largest U.S. carriers flying the 737 Max 8, have declined to ground planes, saying they are confident in the safety and “airworthiness” of their fleets.
Boeing issued a new statement Tuesday saying that no grounding of planes was necessary, however a growing list of countries, including Ethiopia, Britain, France, Australia, and China, as well as individual airlines across the world have already temporarily grounded their 737 Max 8 jets.