Families of victims believed to have been killed when a Boeing 777 plunged into the Indian Ocean cannot pursue their claims against Malaysia Airlines or the beleaguered planemaker in U.S. federal court.

Instead, families of deceased passengers who filed 40 lawsuits in the multidistrict litigation must pursue their claims in Malaysian courts, according to Friday's opinion from the U.S. Court of Appeals for the D.C. Circuit.

"While the court has great sympathy for the victims of this tragedy and their families, we cannot disregard the narrow standard governing our review in this case," wrote Judge Neomi Rao. "We conclude that the district court did not clearly abuse its discretion in dismissing appellants' lawsuits for forum non conveniens and affirm the decision in full."

The panel also included Judges A. Raymond Randolph and Robert L. Wilkins.

Malaysia Airlines flight MH370 disappeared in March 2014 as it flew from Kuala Lumpur to Beijing, and no definitive cause has surfaced. The plane is assumed to have run out of fuel and crashed into the Indian Ocean, killing all on board.

The underlying lawsuits brought passenger rights claims against the airline and its insurer under the Montreal Convention, and state products liability and wrongful death claims against Boeing, which manufactured the aircraft in Washington state. Under the Montreal Convention, which is an international treaty from 1999, passengers from foreign countries can't sue a foreign airline in U.S. courts, which offer significantly higher damage awards.

In the Montreal Convention claims, plaintiffs attorneys focused on the fact that three of the passengers were U.S. citizens, while one had lawful permanent residence in the United States. They also noted that a law allowing Malaysia Airlines to restructure following Flight 370's disappearance could limit the airline's liability.

In 2018, U.S. District Judge Ketanji Brown Jackson in Washington, D.C., dismissed all 40 lawsuits after concluding that "the claims asserted in the consolidated complaints have a substantial and overriding nexus to Malaysia that outweighs the less substantial connection to the United States." She wrote that the dearth of U.S. citizens as passengers or plaintiffs, and the failure to identify the cause of the aircraft's disappearance, prompted her to dismiss the cases under the doctrine of forum non conveniens.

The cases were divided into two groups, with one led by a team from Podhurst Orseck and the Wisner Law Firm, and the other led by Motley Rice and Spagnoletti & Co. They made different arguments on appeal.

Podhurst Orseck's Stephen Rosenthal in Miami and Caitlyn Hubbard, an associate at Kelly Hart & Hallman in Fort Worth, Texas, who filed a separate appeal brief on behalf of the brother of one U.S. citizen, Phillip Wood, argued that Jackson had failed to give them enough deference to sue in U.S. courts.

But the D.C. Circuit said Jackson gave "careful consideration of the foreign appellants' interests in trying these cases in the United States and a thoughtful balancing of the public and private interest factors with respect to those individuals specifically."

"Because the court concluded that even Wood's substantial interest in trying these claims in the United States could not overcome the significant evidentiary problems posed by proceeding in a U.S. court, it necessarily followed that the foreign appellants—who were concededly entitled to less deference than Wood—could not succeed in showing that the balance of interests weighed in favor of maintaining their claims here," the panel wrote.

In a separate brief, Motley Rice's Mary Schiavo had insisted that Malaysia would be an inadequate forum for her clients to pursue their cases because the law provides less compensation. But the D.C. Circuit found that "a U.S. forum would not provide any greater likelihood of redress" against Malaysia Airlines.

Malaysia Airlines is represented by King & Spalding and Boeing is represented by Perkins Coie. Eric Wolff, of Perkins Coie in Seattle, argued the case for both defendants.

Boeing has faced a rash of litigation as of late after it grounded its fleet of 737 Max jets after two other recent crashes. Investigators determined those crashes were caused by a sensor malfunction.

Read more: