CHICAGO (Reuters) - A lawyer for victims of Ethiopian Airlines Flight 302 said on Tuesday he wants Boeing Co and the U.S. Federal Aviation Administration to hand over documents about the decision to keep the Boeing 737 MAX in the air after a deadly Lion Air crash last October.

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A week after Lion Air Flight 610 nose-dived into the Java Sea, killing all 189 aboard, the FAA warned airlines that erroneous inputs from an automated flight control system’s sensors could lead the jet to automatically pitch its nose down, but the agency allowed the jets to continue flying.

Five months later, the same system was blamed for playing a role when ET302 crashed on March 10, killing all 157 passengers and crew and prompting a worldwide grounding of the 737 MAX that remains in place.

“The decisions to keep those planes in service are key,” Robert Clifford of Clifford Law Offices, which represents families of the Ethiopian crash victims, said at a status hearing before U.S. Judge Jorge Alonso in Chicago.

Nearly 100 lawsuits have been filed against Boeing by at least a dozen law firms representing families of the Ethiopian Airlines crash victims, who came from 35 different countries, including nine U.S. citizens and 19 Canadians.

Families of about 60 victims have yet to file lawsuits but plaintiffs’ lawyers said they anticipate more to come. Most of the lawsuits do not make a specific dollar claim, though Ribbeck Law Chartered has said its clients are seeking more than $1 billion.

The lawsuits assert that Boeing defectively designed the automated flight control system. The system is believed to have repeatedly forced the nose lower in both accidents.

Boeing declined to comment on the lawsuit directly but said it is cooperating fully with the investigating authorities. The manufacturer has apologized for the lives lost in both crashes and is upgrading software. But it has stopped short of admitting any fault in how it developed the 737 MAX, or the software.

The FAA said it does not comment on litigation. The agency has defended its decision not to ground the 737 MAX sooner and has said it is following a thorough process for returning the jet to passenger service.

Clifford, who was appointed lead counsel on Tuesday to represent the majority of plaintiffs suing Boeing over the Ethiopian Airlines crash, said he would pursue two tracks in the case: one for clients who wish to settle with Boeing and another for those who want to push for discovery.

In his role as lead counsel, Clifford will help the different plaintiffs “speak with one voice,” said Ricardo Martinez-Cid of Podhurst Orseck, a law firm that is also representing Ethiopian Airlines crash victims.

Plaintiffs’ lawyers who represent victims of airline crashes generally work for free and receive a percentage of the settlement or award.

Amos Mbicha, who lost his sister and her son in the crash of ET302 which occurred soon after it departed Addis Ababa for Nairobi, said some Kenyan families had not sued yet because they had difficulty choosing between the many law firms seeking to represent victims.

“You look at the brochures, it all looks like everyone worked on the same cases,” he said. “It’s confusing for people.”

Dozens of lawsuits have been filed against Boeing by families of Lion Air crash victims, who were almost all from Indonesia. Those cases are already in mediation and are not expected to be consolidated with Ethiopian Airlines.

“While the cases share some common issues there are big differences, most importantly the critical evidence of what Boeing did and did not do between October and March,” said Justin Green, a lawyer from Kreindler & Kreindler, who was appointed co-chair of the plaintiffs’ committee on Tuesday.