NEWARK — As United Flight 731 climbed out of Newark with 107 people aboard, the pilot and first officer were startled to find screens that display crucial navigational information were blank or unreadable and radios were dead.

Within minutes, they had turned around and safely landed the Airbus A320 at Newark. But the January 2008 emergency was far from the first such multiple electrical failure in what is known as the Airbus A320 family of aircraft, and it wasn’t the last, according to records reviewed by the Associated Press.

More than 50 episodes involving the planes, which first went into service more than two decades ago, have been reported.

And it could be another few years before the last of the thousands of narrow-body, twin-engine jets in use in the United States and overseas are modified to counteract the problem. The Federal Aviation Administration issued an order in 2010 giving US airlines four years to make the fixes. The FAA’s European counterpart did the same thing in 2009.

The US pilots union wanted the FAA to give airlines just two years to comply, but the FAA rejected that.

A National Transportation Safety Board investigator said long time frames for fixing problems are not uncommon, because of the inconvenience involved in grounding planes for repairs. And an FAA spokeswoman said the four-year window was determined by the estimated 46 hours required to fix each jet.