Boeing has received approval from the U.S. Federal Aviation Administration (FAA) of the company's plan to test and certify improvements to the 787's battery system. Successful completion of each step within the plan will result in the FAA's approval to resume commercial 787 flights.

"Our top priority is the integrity of our products and the safety of the passengers and crews who fly on them," said Boeing Chairman, President and CEO Jim McNerney.

"Our team has been working around the clock to understand the issues and develop a solution based on extensive analysis and testing following the events that occurred in January. today's approval from the FAA is a critical and welcome milestone toward getting the fleet flying again and continuing to deliver on the promise of the 787," he said.

Ray Conner, president and chief executive officer of Boeing Commercial Airplanes, said that the company's focus has been on developing a permanent resolution.

"Working with internal and external experts in battery technology, we have proposed a comprehensive set of solutions designed to significantly minimize the potential for battery failure while ensuring that no battery event affects the continued safe operation of the airplane," said Conner.

"Our proposal includes three layers of improvements. First, we've improved design features of the battery to prevent faults from occurring and to isolate any that do.

"Second, we've enhanced production, operating and testing processes to ensure the highest levels of quality and performance of the battery and its components. Third, in the unlikely event of a battery failure, we've introduced a new enclosure system that will keep any level of battery overheating from affecting the airplane or being noticed by passengers," Conner said.

Design feature improvements for the battery include the addition of new thermal and electrical insulation materials and other changes. The enhanced production and testing processes include more stringent screening of battery cells prior to battery assembly.

Operational improvements focus on tightening of the system's voltage range. A key feature of the new enclosure is that it ensures that no fire can develop in the enclosure or in the battery. Additional details of the new design will be provided by Boeing in the days ahead.

Boeing made its certification plan proposal to the FAA in late February. today the agency agreed that the proposed changes and the detailed test plans address the conditions that resulted in the suspension of 787 operations.

The FAA also granted Boeing permission to begin flight test activities on two airplanes: line number 86, which will conduct tests to demonstrate that the comprehensive set of solutions work as intended in flight and on the ground; and ZA005, which is scheduled to conduct engine improvement tests unrelated to the battery issue. Additional testing may be scheduled as needed.

The certification plan calls for a series of tests that show how the improved battery system will perform in normal and abnormal conditions.

The test plans were written based on the FAA's standards as well as applicable guidelines published by the Radio Technical Commission on Aeronautics (RTCA), an advisory committee that provides recommendations on ways to meet regulatory requirements. The RTCA guidelines were not available when the original 787 battery certification plan was developed.

"We have a great deal of confidence in our solution set and the process for certifying it," said Conner. "Before 787s return to commercial service, our customers and their passengers want assurance that the improvements being introduced will make this great airplane even better. That's what this test program will do."