The first Dreamliner was delivered in 2011 to All Nippon Airways, Japan’s largest airline. There are more than 1,100 in service today. Air India flies nearly three dozen of the large jets that are typically used for international flights, according to Cirium. The plane involved in the crash, a 787-8, was built in 2013.

But Dreamliner deliveries were paused for more than a year until the summer of 2022, when the Federal Aviation Administration approved a Boeing plan to address quality concerns that included filling paper-thin gaps in the plane’s body and replacing certain titanium parts that were made with the wrong material. None of those problems had an immediate impact on the safety of Dreamliners, Boeing said at the time.

Last year, the F.A.A. said it was also investigating claims by a Boeing engineer that parts of the fuselage, or body, of the Dreamliner were improperly fastened together, which the whistle-blower said could cause premature damage to the plane over years of use.

Boeing disputed that, including at a briefing last year for reporters at the factory in North Charleston, S.C. where the Dreamliner is assembled. Two top Boeing engineers said at the time the company had found no evidence to support the whistle-blower’s concerns after conducting exhaustive tests, inspections and analyses of the plane during its development and in recent years.

One 787 airframe was subjected to testing that put it through 165,000 “flight cycles,” and the equivalent pressurization and depressurization of as many flights. That figure far exceeded the plane’s expected useful life and the airframe still showed no signs of fatigue, Steve Chisholm, a vice president and the functional chief engineer for mechanical and structural engineering at Boeing, said at the briefing in South Carolina.

At the time, the Dreamliner with the longest record had seen only about a tenth as many flights in the dozen years it had been in operation, the company said. Boeing had also said then that nearly 700 Dreamliners had gone through thorough six-year maintenance checks, and eight had gone through 12-year checks. Mechanics found no signs of premature fatigue in those jets, Boeing said.

Other whistle-blowers have also raised concerns about the South Carolina factory where the Dreamliner is assembled. Among them was John Barnett, a former quality manager with almost three decades of experience at Boeing, who went public with his concerns in 2019. He and other people who had worked at the factory highlighted shoddy practices, including the improper routing of wires and manufacturing tools and debris left inside planes.

Mr. Barnett killed himself last year after a yearslong legal battle with the company, which he accused of retaliating against him over his speaking out. Last month, Boeing settled a lawsuit with Mr. Barnett’s family concerning his death.