Several pilots made at least five complaints about Boeing 737 Max 8 planes in the months leading up to the deadly Ethiopian Airlines crash on Sunday, the second crash of a Boeing 737 Max 8 in recent months.
US 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,” according to the Dallas Morning News.
The complaints were made in the Federal Aviation Administration’s incident database which allows pilots to report issues about aviation incidents anonymously.
The complaints highlighted issues with the Max 8’s autopilot system, which has been called into question following the crash of Lion Air Flight 610 in October. That incident also involved a Boeing 737 Max 8 plane.
According to the black box recovered from the Lion Air crash, Flight 610 was repeatedly pushed into a dive position, most likely because of the automated system’s malfunctioning sensors, a fault that began moments after it took off from Jakarta en route to Bali. All 189 people on board were killed in that crash.
Ethiopian Airlines CEO Tewolde GebreMariam told CNN that the similarities between the Lion Air crash and Sunday’s crash are “substantial.”
“He was having difficulties with the flight control of the airplane, so he asked to return back to base,” GebreMariam said.
Complaints focused on the autopilot system
In one complaint, a commercial pilot described issues which occurred during takeoff. As the autopilot was engaged, the aircraft’s nose suddenly pitched down, setting off the plane’s alarm system which sounded “Don’t sink, don’t sink!” according to Politico. The situation was only remedied after autopilot was turned off, it added.
Another pilot who flies the Max 8 complained in November that it was “unconscionable” that pilots were allowed to continue to fly the planes without adequate training or disclosure on how the Max 8’s system differs from previous models, Politico said.
“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,” the pilot said in the report.
In an October report, a pilot complained the Max autothrottle system did not work properly even when they were engaged. The problem was rectified after the pilot adjusted the thrust manually and continued to climb.
“Shortly afterwards I heard about the (other carrier) accident and am wondering if any other crews have experienced similar incidents with the autothrottle system on the Max?” the pilot wrote in the report.
Boeing faces backlash
Since Sunday’s crash, Boeing has faced backlash over its Max planes as investigators continue to look into what happened to the Ethiopian Airlines Flight 302.
Countries and airlines around the world have begun grounding Boeing 737 Max planes for inspection.
On Tuesday it was reported that Boeing’s market value has plunged by $40 billion from its 2019 peak. Shares have slumped about 15% since topping out on March.
In response, Boeing announced that all Max planes will be receiving updated flight-control software in the coming weeks, though the company has not indicated whether it will make physical changes to the aircraft, which has been in service since last spring.
“At the heart of the controversy surrounding the 737 Max is MCAS, the Maneuvering Characteristics Augmentation System,” Business Insider transportation correspondent Benjamin Zhang wrote.
“To fit the Max’s larger, more fuel-efficient engines, Boeing had to redesign the way it mounts engines on the 737. This change disrupted the plane’s center of gravity and caused the Max to have a tendency to tip its nose upward during flight, increasing the likelihood of a stall,” Zhang said.
“MCAS is designed to automatically counteract that tendency and point the nose of the plane downward.”