A whistleblower who accused a Boeing supplier of ignoring defects in the production of the 737 MAX has died, family members and his lawyer have said.

Joshua Dean, a former Spirit AeroSystems employee who alleged he was fired in retaliation for flagging lax standards at the companys Wichita, Kansas, manufacturing plant, died on Tuesday after a sudden illness, his aunts and sister said in posts on social media.

Deans lawyer Brian Knowles said his clients death was a loss to the aviation community and the flying public.

He possessed tremendous courage to stand up for what he felt was true and right and raised quality and safety issues. Aviation companies should encourage and incentivise those that do raise these concerns. Otherwise, safety and quality are truly not these companies top priorities, Knowles told Al Jazeera.

Spirit AeroSystems said the companys thoughts were with his family.

This sudden loss is stunning news here at Spirit and for his loved ones, a spokesperson told Al Jazeera.

Deans mother wrote in a Facebook post last month that her son was fighting for his life after contracting pneumonia and suffering a stroke following an MRSA infection.

The Seattle Times, which first reported his death, said Dean was 45 years old and had been in good health and was noted for having a healthy lifestyle.

Deans death comes less than two months after Boeing whistleblower John Barnett was found dead from what South Carolina authorities said was an apparent self-inflicted gunshot wound.

Barnett, 62, had been in the midst of a deposition in a lawsuit against Boeing after suffering retaliation for exposing safety problems with the Boeing 787 Dreamliner, according to his lawyers.

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Spirit AeroSystems has been under scrutiny since it emerged that it built the door panel that blew out of a 737 MAX 9 in mid-flight in January.

The near-disaster involving Alaska Airlines Flight 1282, which is the subject of several probes, was the latest in a series of incidents to raise concerns about safety standards at Boeing.

Dean had filed a complaint against Spirit with the Federal Aviation Administration alleging serious quality failings at its production facility and testified in a shareholder lawsuit against the company.

Dean told US outlet NPR in February that he believed he had been fired to send a message to others thinking of speaking out.

If you are too loud, we will silence you, he was quoted as saying.(Al Jazeera, excluding headline)

PHOTO: Spirit AeroSystems has been under scrutiny over its role in a midair blowout involving a Boeing 737 MAX 9 in January [National Transportation Safety Board via AP]