Boeing’s newest and most sophisticated jet, the 787 Dreamliner, suffered more mishaps on Friday, when an airline in Japan reported incidents involving planes on two domestic flights, according to The New York Times.

Cracks appeared Friday in the cockpit window of a 787 Dreamliner and this was the third time that cracks had appeared in the windshield. The other two incidents happened last year.

In the second incident also in Japan, oil was discovered to be leaking from one of the 787’s engines. Although both issues were minor, they came just days after three other safety incidents involving the aircraft revived concerns about the plane’s reliability and safety.

On Wednesday, flight in Japan was cancelled after an onboard computer on 787 mistakenly showed problems with the aircraft’s brakes.

On Tuesday, a fuel leak forced a 787 operated by Japan Airlines to return to its gate minutes before taking off from Boston. And on Monday, an electrical fire broke out on another plane, also operated by Japan Airlines from Logan International Airport, in Boston.

Although the problems so far do not point to serious design flaws with the airplane, they represent an embarrassment to Boeing’s manufacturing ability, analysts have said.

Japan’s Transport Ministry, which oversees aviation safety in the country, for now did not see any need to raise alarm over the new aircraft’s safety.

According Japanese officials, even considering that the 787 is a new aircraft, which tends to come with initial glitches, they are not seeing a higher incidence of reported problems compared to other aircraft.

The US Federal Aviation Administration said Friday they would order a review of electrical systems in Boeing’s new 787 Dreamliner following these incidents.

Japan is the first country in the world to own the Dreamliner followed by Ethiopia.