A former Boeing official who played a key role in the development of the 737 MAX has refused to provide documents sought by federal prosecutors investigating two fatal crashes of the jetliner, citing his Fifth Amendment right against self-incrimination, according to a person familiar with the matter.

Mark Forkner, Boeing’s chief technical pilot on the MAX project, invoked the privilege in response to a grand jury subpoena issued by U.S. Justice Department prosecutors looking into the design and certification of the plane, the person said.

Invoking the Fifth to avoid testifying, while a legal right, is sometimes interpreted as an admission of guilt. Its use to resist a subpoena for documents is less common and may only imply a dance between prosecutors and defense attorneys, legal experts say.

Forkner, now a first officer for Southwest Airlines, referred questions to his attorney when reached by phone. His attorney, David Gerger, of Houston, did not respond to inquiries.

Justice Department spokesman Peter Carr declined to comment. Boeing also declined to comment.

Prosecutors in the Justice Department’s Washington, D.C., fraud section are conducting a wide-ranging investigation into the crashes that occurred Oct. 29 off Indonesia, and March 10 in Ethiopia, killing 346 people and leading to worldwide grounding of the plane.


Their investigation includes the role of a new flight-safety control system called the Maneuvering Characteristics Augmentation System (MCAS), which has been implicated in the crashes.

Forkner, who worked at Boeing from 2011 to 2018, according to his LinkedIn profile, was frequently anxious about the deadlines and pressures faced in the MAX program, going to some of his peers in the piloting world for help, a person who worked on the project previously told The Seattle Times, speaking on condition of anonymity.

The MCAS system, designed to move a powerful control surface at the tail to push the airplane’s nose down in certain rare situations, played a critical role in the crashes when the planes nose-dived out of the sky.

During the certification process, Forkner suggested to the Federal Aviation Administration (FAA) that MCAS not be included in the pilot manual, according to previous Seattle Times reporting.

The FAA, after internal deliberations, agreed to keep MCAS out of the manual, reasoning that MCAS was software that operates in the background as part of the flight-control system, according to an official familiar with the discussions.

In addition, Boeing won the FAA’s approval to give pilots just an hour of training through an iPad about the differences between the MAX and the previous 737 generation. MCAS was not mentioned.


Boeing has said MCAS was only one link in a chain of events, and that MCAS was designed according to the standard procedures it has used for years.

“The 737 MAX was certified in accordance with the identical FAA requirements and processes that have governed certification of previous new airplanes and derivatives,” the company said in a previous statement.

Gerger, in an earlier interview, said, “Mark never dreamed anything like this could happen. He put safety first.”

It isn’t clear when Forkner received the subpoena or if the Justice Department, as part of the secret grand jury proceedings, has asked a judge to compel disclosure of the documents.

Also unknown is whether Forkner and the Justice Department have discussed terms under which he might surrender the documents, and whether subpoenas have been issued to other individuals for records.

While the Fifth Amendment protects people from testifying against themselves, it “usually does not apply to being required to produce documents because producing a document is not the same as being required to testify,” said University of Washington law professor Jeffrey Feldman.


But there are exceptions that allow the privilege to be asserted where “the mere act of producing the document” may be seen as an incriminating act, Feldman said.

Paul Rothstein, a Georgetown University law professor, said documents may show a person “has them, knows about them or admits they exist.”

“This information can often be somewhat incriminating of that person and thus covered by his Fifth Amendment privilege against self-incrimination,” Rothstein said.

Some courts have held that broad document requests require the person to “use his or her mental processes to interpret and respond to the subpoena, and the production itself could be viewed as testimonial,” said Peter Joy, a Washington University law professor.

In Forkner’s case, Feldman said, it could turn on the type of documents. “Are these the employee’s personal documents? His diary or personal emails? Or are they Boeing’s documents?”

Forkner could ask for immunity from use of the information in the documents, or prosecutors could offer it, the experts said.


“Such immunity means the revealed information cannot be used in any way in any investigation of him or any criminal prosecution of him,” Rothstein said, noting that it is not a blanket immunity from investigation or prosecution based on evidence obtained elsewhere.

It is “just an immunity from use of this particular evidence or information,” he said.

But prosecutors can independently seek other evidence, Feldman said.

He said if there is a plausible assertion of the privilege, it would “not be unusual to see the government offer” of immunity.

“It could just be the kind of waltz you often see in cases like this, by which individuals who are concerned that they may get swept up in a criminal matter try and obtain some protection and assurances to lower their risk,” Feldman said. “Or it could be much more significant both for the individual or the company.”