The Boeing 787 Dreamliner has faced another issue. Gas was discovered coming out of a battery on a plane in Tokyo.

Fortunately the plane was parked at the time and the problem was discovered on the Japan Airlines plane as it was undergoing scheduled maintenance. No passengers were on the aircraft at the time, the Daily Mail reports.

Boeing says it appears that a single battery cell was releasing gas.

This comes just a year after there a lithium ion battery caught fire on another Japan Airlines 787 that was parked at Logan International Airport in Boston. That incident came just nine days before another battery incident which forced an All Nippon Airways 787 to make an emergency landing in Japan. Following these incidents, the FAA grounded all 787 Dreamliners for about three months.

During that time, Boeing changed the battery system by adding a sturdier box to hold the battery and fixed issues to contain a short-circuit or fire. The company said those changes were working in the incident on Tuesday. The company also said its working with Japan Airlines to get the plane back in the skies.

Japanese authorities are investigating the incident. The U.S. National Transportation Safety Board may investigate as well if the Japan Transport Safety Board opens an investigation. The NTSB said the incident is nothing more than a smoke event at this time.

The NTSB is still investigating the incident last January in Boston. That investigation is expected to be compete by March and the findings will be presented in the fall.

"Anything we can learn about the (latest) battery failure would be helpful (to the ongoing investigation),"NTSB spokesman Peter Knudson said according to the Mail.

Boeing and the Civil Aviation Bureau of Japan are cooperating with the Federal Aviation Administration to investigate the latest issue.

It isn't clear what caused the battery to smoke in the first place.