UPDATE 2-Faulty American Airlines jet lands safely in Miami

(Updates with American Airlines comment, MD-80 details)

MIAMI, Feb 22 (Reuters)- An American Airlines jetliner with 138 people on board landed safely at Miami International Airport on Friday after being diverted because of a problem with its nose gear, officials said.

The single-aisle MD-80 will be taken out of service for checks, but the rest of American Airlines' 275-strong active fleet of MD-80s will continue flying, said a spokesman for the airline, which is a unit of AMR Corp AMR.N.

The aircraft was American flight 862 from West Palm Beach, Florida, to Chicago’s O’Hare airport, airport spokesman Greg Chin said. The plane circled the airport to burn off fuel before landing safely.

Problems with retracting front landing gear are rare, but not unprecedented, said American Airlines spokesman Tim Smith.

“This was not an extraordinary event,” he said. “It is one we train for.”

The 133 passengers on the flight will be put on a Boeing BA.N 737 flight to Chicago around 6 p.m. EST tonight, Smith said. Boeing's 737 is the usual single-aisle plane American operates out of Miami International Airport.

The MD-80, the workhorse of American Airlines’ domestic fleet, was originally made by McDonnell Douglas, which is now part of Boeing. The plane type entered service in 1980 and was last produced in 1999.

A single-aisle, medium-range, twin-engined plane, it is designed to carry as many as 172 passengers, but usually carries around 140 in a typical configuration. (Reporting by Jim Loney, additional reporting by Bill Rigby in New York; Editing by Eric Walsh)