TOKYO — ANA Holdings, the world’s largest operator of Boeing 787 aircraft, said it found wiring defects in three of its Dreamliners, a discovery that prompted rival Japan Airlines to order a flight to return home.
ANA found improper wiring for the fire-suppression system on a Dreamliner before it was to depart from Tokyo’s Haneda airport Wednesday, spokeswoman Megumi Tezuka said by phone. The faulty wiring activates the wrong fire extinguisher in the event of a fire in one of the two engines, she said, adding the defect occurred during the manufacturing process.
The Tokyo-based airline replaced parts in two of the aircraft in which it found the defect, she said. The carrier operates a fleet of 20 787s.
“We will thoroughly examine this issue and take the appropriate steps,” Rob Henderson, a spokesman for Boeing, said in Tokyo. “The safety of those flying on Boeing airplanes is our top priority.”
Japan Air inspected five of the 10 Dreamliners in its fleet and found no issues, said Seiji Takaramoto, a company spokesman. The Dreamliner has moved from one safety check to another since the failure of lithium-ion batteries on two 787s in January grounded the global fleet of the plastic-composite jet for three months.
“These things happen with a new aircraft,” said Robert Stallard, a London-based analyst at RBC Capital. “When the airlines ground the plane or regulators start becoming involved, then it becomes something to watch out for.”
Japan Air said it got the information about wiring from the Transport Ministry, according to a statement the carrier sent Wednesday. Upon receiving the note, the plane bound to Helsinki returned to Narita airport in Tokyo, said Takaramoto. The company will inspect wiring on all its 787s Wednesday, he said.
Last month, U.S. regulators ordered Dreamliner operators to check emergency radio transmitters for wire damage after a beacon was linked to the July 12 fire on one of the jets in London. The Federal Aviation Administration is working with Chicago-based Boeing to develop instructions for the inspections, the agency said at the time.
Boeing had delivered 73 Dreamliners to 13 customers through August 7, the company said on its website, with more than 29,000 flights flown. Japan is the biggest customer of the jet.
Japan Air and ANA restarted services with the Dreamliner in June after authorities approved Boeing’s redesign of the batteries, which included more protection around individual cells to contain any overheating.