Boeing whistleblower John Barnett was found dead in his car with a gunshot wound to his head on the same day he was due to testify against the aircraft manufacturer.

The mysterious incident happened as the company’s stock has nosedived, fueled by a series of incidents including a door plug which flew off a 737 MAX 9 operated by Alaska Airlines at 16,000 feet on Jan. 5 and a wheel falling off a 777 jet a few weeks later.

This led the Federal Aviation Administration’s (FAA) to investigate and discover “unacceptable” quality control issues.

While Barnett’s death has raised many eyebrows, it is far from the first incident involving the company’s workers.

Here we take a look back at some of Boeing’s biggest scandals.

2008: Disgruntled worker admits cutting chinook wires over ‘work stress’

A disgruntled worker at a Boeing plant told a court that he cut about 70 electrical wires on a $24 million Chinook military helicopter because he was upset about a job transfer.

Matthew Montgomery, 33, pleaded guilty in 2008 to one count of destroying property under contract to the government.

According to federal prosecutors, Montgomery was working his last shift on the Chinook assembly line May 10, 2008 when he severed about 70 electrical wires running together from the cockpit to the main body of an H-47 Chinook.

He was later sentenced to five months in prison and five months in home confinement after telling the judge the tension and tedium of his assembly-line job had gotten to him.

“I know now that a factory environment is not the place for me,” Montgomery said in court.

2011: Feds arrest 23 in Boeing plant drug raid

Almost two dozen past and then-current employees were arrested in a drug bust at a Boeing plant which makes military aircraft in Pennsylvania, with the charges including selling Oxycontin and fentanyl, officials said.

In a major sting, FBI and Drug Enforcement Administration (DEA) agents uncovered the illegal prescription drug distribution ring at the Ridley Park-based factory, leading to indictments against 23 individuals, a joint statement from the agencies said.

“The defendants in this case are accused of diverting controlled substances and selling them to alleged abusers without any medical supervision,” said DEA Acting Special Agent in Charge, Vito Guarino, in 2011.

The drugs being sold on site at the facility – which builds aircraft including the H-47 Chinook helicopter and the V-22 Ospre – included fentanyl and oxycodone, also known as Oxycontin.

Boeing had brought its suspicions of drug activity to federal law enforcement and the Justice Department said it had cooperated fully with the long-term investigation.

FBI agents used Boeing employees to cooperate in the probe, and those charged were accused of either selling drugs to FBI cooperators or buying placebo drugs from them, officials said.

Boeing commended the U.S. agencies for their “rigorous and thorough investigation.

All 23, including a union chief, had all pleaded guilty by August 2012, according to a report in the Philadelphia Enquirer.

2014: Boeing workers claim coke and meth used while on the job

In a damning 2014 video clip, several Boeing employees claimed colleagues were on hard drugs including cocaine and meth while they worked, and raised concerns about the safety of the 787 Dreamliner aircrafts.

Current and retired Boeing employees discussed their worries about quality control with news service Al Jazeera’s investigative TV segment “Broken Dreams: The Boeing 787”.

On a video secretly taken at the plant by a worker and leaked to the network, one Boeing employee said he has seen “people talking about doing drugs, looking for drugs”, specifically marijuana, cocaine and prescription painkillers.

In the footage, he records one man saying: “It’s all coke and painkillers” at the plant, adding, “you can get weed here, you can get some really good weed here”.

Another, who spoke on condition of anonymity, complained that Boeing “don’t drug test nobody”, adding that “there’s people that go out there on lunch and smoke one up”.

In a statement at the time, Boeing said: “Drug testing of employees is done in accordance with Boeing … Boeing thoroughly investigates any employee reports of policy deviation, and appropriate corrective action is taken if needed.”

Using the hidden camera, the worker filmed 15 colleagues inside the Boeing South Carolina plant assembling the 787 Dreamliner and asked if they would fly on the plane. Ten said they would not, according to Aljazeera.

“I wouldn’t fly on one of these planes,” one worker tells him, “because I see the quality of the f—g s–t going down around here”.

In a statement, Boeing said: “787 airplanes … meet the highest safety and quality standards that are verified through robust test, verification and inspection processes.”

2022: Boeing blamed for murder-suicide of colleagues in love triangle

Boeing’s failure to act after learning two of its employees were involved in love triangle with their supervisor resulted in one of the employees murdering his co-worker, according to a lawsuit filed in 2022.

The estate of former Boeing employee Isaiah Washington, 28, filed the Boeing negligence lawsuit after he was fatally shot on the street by co-worker Ralph O’Connor, 44, who then killed himself.

In January this year, the company argued the employees were not on the clock when the murder occurred, in a bid to have the case tossed.

According to the King County Medical Examiner, Washington was shot several times, and O’Connor then shot himself.

The lawsuit alleges both men had been in sexual relationships with Boeing supervisor Rachel Pettit, leading to threats from O’Connor against Washington.

Boeing was made aware of the threats and O’Connor’s history of threatening behavior, according to the lawsuit.

Lawyers for Boeing said O’Connor left the company after it learned of messages he had sent, including one where he told coworkers he wanted to “pull the trigger”.

In their motion asking for the lawsuit to be dismissed, the company said: “the complaint contains no allegations suggesting that Boeing knew or should have known that O’Connor might kill or harm someone other than himself.”

The civil case has yet to be resolved.

2024: FAA finds ‘multiple instances’ of quality control issues in audit

The FAA’s six-week audit of Boeing’s 737 MAX manufacturing processes faulted numerous company processes, including mechanics at one of its key suppliers using a hotel key card and dish soap as makeshift tools to test compliance, according to a report.

The FAA discovered “unacceptable” quality control issues during an audit of Boeing and supplier Spirit AeroSystems that was launched after a door plug flew off a 737 MAX 9 at 16,000 feet on Jan. 5.

Boeing failed 33 out of 89 product audits — a review of specific aspects in the production line — with a total of 97 counts of alleged noncompliance, the auditors found.

“We have a clear picture of what needs to be done. Transparency prevailed in all of these discussions,” Boeing said in a statement following the FAA’s probe.

Last Tuesday, the company revealed it is adding weekly compliance checks for every 737 work area and additional audits of equipment to reduce quality problems, in a memo to employees.

2024: Whistleblower found dead in mysterious circumstances

John Barnett, a 62-year-old longtime Boeing employee who went public with safety concerns about the 787 Dreamliner, died a day after sitting for a deposition with the company’s lawyers on March 9 this year.

His lawyers raised the alarm after he failed to show up for a deposition in Charleston, South Carolina. 

A coroner’s report preliminarily said he died from a “self-inflicted” wound, but the Charleston Police Department is still making inquiries.

A “close family friend” of Barnett, who gave her name only as Jennifer to ABC News 4 claimed he had told her not to believe any reports of his suicide before his death.

She claimed he had insisted “I ain’t scared” before adding “but if anything happens to me it’s not suicide.”

Jennifer told the program she believes somebody “didn’t like what he had to say” and wanted to “shut him up”.

Those claims have not been verified and there is no suggestion of Boeing being involved in any foul play.

Boeing also released a statement, saying: “We are saddened by Mr. Barnett’s passing, and our thoughts are with his family and friends.” 

Barnett’s lawyers, Robert Turkewitz and Brian Knowles, are also suspicious.

They said in a statement: “John was a brave, honest man of the highest integrity.

“He cared dearly about his family, his friends, the Boeing company, his Boeing co-workers, and the pilots and people who flew on Boeing aircraft. We have rarely met someone with a more sincere and forthright character.”

The investigation into his death is ongoing and sources previously told The Post police had dusted his car for fingerprints inside and out, a highly unusual move in suicide cases.