A United Airlines flight from New Orleans to San Francisco returned to the New Orleans airport within minutes of taking off Monday after the pilot reported smoke in the cockpit, the Federal Aviation Administration said.
All 100 passengers and five crew members on Flight 497 were safe, airline spokesman Rahsaan Johnson said.
Copilot Ronald Lee Young told an Associated Press reporter aboard the Airbus 320 that he landed on backup systems, with minimal steering and braking ability, after the plane lost all electronics.
"When things start to go wrong, there's always a system ... we can go back to," he said.
FAA spokesman Lynn Lunsford said he had not been told about any electronic failure. He said the pilot had declared an emergency because of smoke in the cockpit.
Young said the plane, heavy with fuel for the cross-country flight, ran off the runway and blew a tire.
Only the nose wheel ran off the pavement, Lunsford said. He said investigators were on their way to find out more about what happened.
As soon as the plane was on the ground, flight attendants shouted "Leave everything. Get out!" Passengers slid down the front and back slides.
A few passengers walked to an ambulance after a call for anyone with injuries. The injuries appeared to be minor, such as abrasions from the slide.
Online records from the Federal Aviation Administration show the plane was built in 1994.