The former inspector general for the U.S. Transportation Department has filed a lawsuit against Boeing Co. alleging the aerospace giant knew its 737 Max jet was unsafe but concealed the plane's dangerous design flaws from airlines and the public.

Mary Schiavo, the U.S. DOT's inspector general from 1990 to 1996, filed the lawsuit in federal court in Charleston on behalf of the estate of George Thugge, a passenger who was killed in the March 10 crash of an Ethiopian Airlines 737 Max 8. Thugge was a resident of Sweden and his estate administrator is a Charleston resident.

The lawsuit draws parallels to a pair of 737 crashes in the early 1990s and argues the Federal Aviation Administration long ago relinquished most of its oversight of Boeing, allowing the manufacturer to inspect and certify its own planes.

Boeing spokesman Charles Bickers said the company won't comment on the lawsuit directly.

"As the investigations continue, Boeing is cooperating fully with the investigating authorities," he said.

The company has repeatedly said there are no design flaws with the 737 Max and the planes are safe.

"We’re committed to providing the FAA and global regulators all the information they need, and to getting it right," Boeing CEO Dennis Muilenburg said in a statement last week. "We’re making clear and steady progress and are confident that the 737 Max with updated ... software will be one of the safest airplanes ever to fly."

Boeing builds its wide-body 787 Dreamliner planes in North Charleston. The single-aisle 737 Max jet that was involved in the Ethiopian Airlines crash and a fatal Lion Air accident in October is built in Renton, Wash.

Schiavo, in the lawsuit, said the FAA has continuously allowed Boeing to build new 737 models — including the Max version — under the same certificate that was used for the original 737 in 1967.

That has allowed Boeing to "race the new models through design, engineering, development and production by 'cutting and pasting' prior models and prior documentation, knowing Boeing would be permitted by the FAA to self-certify," the lawsuit states.

The shortcut, according to the lawsuit, was designed to help Boeing bring its Max planes to market to compete with French plane maker Airbus, which was developing a new single-aisle jet.

Schiavo, now a lawyer with the Motley Rice firm in Mount Pleasant, said Boeing's reaction to the Ethiopian Airlines and Lion Air crashes mirrors the company's actions following a pair of 737 accidents in 1991 and 1994. Those earlier crashes involved 737s that nose-dived to the ground after pilots experienced sudden and unexpected rudder movements.

Unlike the redundancies built into most plane systems, the rudders at the time were a "single point of failure risk" without a built-in backup system. Investigations into the most recent crashes point to a software problem that forced the nose down on 737 Max planes after a single angle-of-attack indicator gave faulty readings.

Boeing "deployed a common and continuous scheme after both series of crashes to conceal deadly faults in the aircraft that caused the planes, without pilot input or ability to overcome the aircraft, to dive into the ground killing all aboard," the lawsuit states.

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Thugge was one of 157 people who died in the Ethiopian Airlines crash. He had connected onto the flight on a trip that departed from and was to return to Stockholm, Sweden.

Boeing delivered the 737 Max 8 jet to Ethiopian Airlines on Nov. 15, weeks after the Lion Air crash that killed 189 people.

"Boeing continued to misrepresent to the FAA that the Boeing 737 Max 8 was safe, even after the crash of Lion Air, because Boeing would suffer significant financial losses if the FAA grounded the airplane," the lawsuit states. "In doing so, Boeing chose to prioritize its profits ahead of the safety of crew members and passengers."

The FAA eventually grounded the 737 Max on March 11, after regulators around the world had already banned the plane from flying. Boeing has developed software changes for the plane but they’re likely to be grounded for at least part of the summer.

Boeing has been under siege in recent weeks, with a flurry of media reports questioning the company’s safety record and production practices.

That includes reports of shoddy production and safety lapses at the 787 Dreamliner campus in North Charleston. Workers at the plant told The Post and Courier that there are repeated mistakes daily at the site, such as: parts and debris left on planes; poorly installed equipment; and planes being rolled out of the assembly building to meet scheduling deadlines even though they still need work.

A program that lets mechanics inspect their own work on about 90 percent of production tasks is being blamed for the mistakes. At the same time Boeing is relying on mechanics to check their own work, the company is eliminating many of its quality inspectors and assigning them to other jobs.

Boeing said its first-quarter costs increased by about $1 billion due to the 737 Max groundings and all deliveries of the jet have been put on hold. There are about 4,000 unfilled orders for Max planes.

Reach David Wren at 843-937-5550 or on Twitter at @David_Wren_