Boeing traced the source of the improper configuration to the supplier of the fire extinguisher bottles, United Technologies subsidiary Kidde. According to JAL, in the event of a fire in one engine, the improper installation could have resulted in the discharge of fire suppressant to the wrong engine. The airframer said it would follow standard procedures to determine how the discrepancy occurred and ensure it does not happen again.

“The safety of crews and passengers on board our airplanes is our top priority,” said Boeing in a statement. “An engineering review has determined that this improper configuration does not present an immediate safety of flight issue because the bottles are not the only means of fire extinguishing for engines and there are multiple redundancies within the fire extinguishing system. Regardless, improperly configured components are not acceptable and this issue is being addressed promptly.”

ANA discovered the problem on Wednesday morning, forcing it to delay a flight from Tokyo Haneda Airport to Frankfurt for an hour and 42 minutes. After receiving word about the ANA incident, JAL decided to inspect its entire 787 fleet and abort a flight en route to Helsinki and return it to Tokyo Narita. The airline re-accommodated the 183 passengers on another 787 some 7 hours and 15 minutes after the original departure time.