On Wednesday, Boeing (NYSE:BA) 787 Dreamliner jets owned by Air India returned to passenger service.
The move came as a top Boeing executive told Reuters that the aircraft maker will complete the installation of new battery containment system on all existing Dreamliners by the end of June. On Tuesday, Boeing began making new deliveries of the jets to waiting customers.
Aviation regulators around the world grounded all 787 Dreamliners in January after a string of emergency landings were linked to overheating of the planes’ lithium-ion batteries.
In March, the company began testing a new containment system meant to prevent battery over-heating. Last month, the U.S. Federal Aviation Administration cleared the new containment system for installation on Dreamliner jets.
Analysts say that the worldwide grounding and repair of the Dreamliners has cost Boeing up to $600 million. The company has not revealed its own estimate of the cost, but has moved quickly to get the planes back into the air.
Shares of Boeing were mostly flat in Wednesday morning trading.