The US Federal Aviation Administration said Monday a joint review with Boeing has found that the 787 Dreamliner's design, manufacture and assembly processes met the aircraft's intended safety level.
The FAA-Boeing review team was formed after two battery fire incidents in less than two weeks in January 2013 that led regulators to order a global grounding of the airplane.
The grounding was lifted three months later in April after Boeing won FAA approval of a battery fix.
The team found that the aircraft was soundly designed, met its intended safety level, and that the company and the FAA had "effective processes" in place to identify and correct any issues that emerged before and after its certification of airworthiness.
"After the first Boeing 787 battery incident last year, I called for a comprehensive review of the entire design, manufacture and assembly process for the aircraft as well as a critical look at our own oversight," FAA Administrator Michael Huerta said in a statement.
Boeing's 787 Dreamliners have suffered a series of problems since coming into service, including a cracked windshield, a fault with an air pressure sensor and a fuselage panel that fell off during landing. In early March the company reported hairline cracks were found in the wings of some of its 787s, blaming a supplier's manufacturing problem.
The FAA-Boeing review team determined that the 787's reliability, since entering service in October 2011, was similar to other new Boeing models over the same 16-month period, the FAA said.
"The review team identified some problems with the manufacturing process and the way we oversee it, and we are moving quickly to address those problems," Huerta said.
Both the FAA and Boeing said they were taking steps to implement the team's recommendations for further improvements, including that Boeing and its suppliers identifying realistic program risks.
The FAA meanwhile will step up manufacturing oversight.
"The findings validate our confidence in both the design of the airplane and the disciplined process used to identify and correct in-service issues as they arise," said Ray Conner, Boeing Commercial Airplanes president and chief executive, in a separate statement.