Boeing on March 25 conducted a functional check flight of a 787 fitted with the revised lithium-ion battery system as a preliminary step toward a certification demonstration flight planned for the coming days.

The Boeing-owned aircraft, Line Number 86, destined for LOT Polish Airlines, made the relatively short flight around the Washington and Oregon coast test areas following a final series of pre-flight ground tests at Paine Field, Everett, on March 24. Boeing says the flight, which began at 12.11 p.m., was “a normal Boeing production check flight intended to validate that all systems function as designed.” During the roughly two-hour sortie, the crew checked the back-up systems and cycled the landing gear, as well as performed electrical systems checks.

In a statement, Boeing says that “following the completion of the functional check flight, we will analyze the data from the flight and prepare for certification ground and flight demonstration in the coming days. The plan is to conduct one certification demonstration flight. That flight, which will take place on Line 86, will demonstrate that the new battery system performs as intended during flight conditions.”

At Boeing Field, close to Seattle, the company also is preparing 787 development test aircraft ZA005 for ground tests of the revised battery–particularly the new stainless steel enclosure and its associated venting system. There has been no notification about when specifically this might occur, although the company says it aims to complete both the certification flight test and associated ground test “in days.”

Pending completion of certification and FAA approval for the battery system modifications, Boeing aims to immediately restart production test flights at Everett, as well as its North Charleston, S.C., production facility. Several production test flights also are scheduled for 787s that have been stored at a paint facility near Fort Worth for the duration of the grounding of the fleet following two separate battery failures in January.

Separately, the NTSB said its upcoming forum, “Lithium-Ion Batteries in Transportation,” will be held April 11-12. The NTSB event, which was announced on March 7 when the safety board released its interim factual report on the Jan. 7 Japan Airlines Boeing 787 battery fire investigation, will focus on design, development and performance of the batteries, as well as related regulatory and safety aspects of the technology.