A man who lost his wife, three children and his mother-in-law in the ET302 Ethiopian Airline crash in March this year will today testify before the congress in the US.
Mr Paul Njoroge, 34, in an interview with US media said Boeing should scrap the plane and the top executives should resign and face criminal charges.
The distraught Kenyan said Boeing should have grounded the 737 Max planes after a previous deadly crash off the Indonesian Coast in October last year, but instead they kept allowing them in the sky.
USA Today reported that Mr Njoroge said if Boeing and the Federal Aviation Administration had done their job properly, the planes would have been grounded in November last year.
"Today, I would be enjoying summer with my family, I would be playing football with my son," the US news site quoted him.
Mr Njoroge will be the first relative of the crash victims to testify before the congress, over the crash that claimed the lives of 346 passengers when the two planes crashed in Indonesia and Bishoftu in Ethiopia.
He had earlier said that the families of the passengers had several demands that they wanted met before the aircraft model is allowed to fly again, citing 'irredeemable design flaws'
A Chicago aviation lawyer, Robert Clifford, is sueing Boeing on Mr Njoroge's behalf over the deaths of his wife, Carol, his son and daughters, 6-year-old Ryan, 4-year-old Kelli and 9-month-old Rubi, and his mother-in-law.
The Max was grounded worldwide shortly after that crash and it's not clear when it will be certified to fly again.
American Airlines and United Airlines earlier this month both said they will keep the Boeing 737 Max plane off their schedule until November 3, leading to flight cancellations.
Mr Njoroge's mother in law Anne Wangui Karanja, his wife and three children perished as they were coming home from Canada to introduce the youngest member of the family to Anne's husband, Quindos Karanja in Kwa Amos village, Kabatini, in Bahati, Nakuru County.
Anne had been living in Canada for five months, where she had gone to help her daughter, after giving birth and had two other young children to take care of.