They were provided with wet towels to hold over their faces in case the acrid smell became too strong.
Journalists travelling with the First Lady reported that a thin haze of smoke and a burning smell spread through the plane around 10 minutes after it took off.
She could be seen safely walking off the plane after the flight returned to Joint Base Andrews in Maryland.More news: Jordan Henderson watches England's victory in Spain with fans
First Lady Melania Trump's airplane was forced to make a landing at Andrews Air Force base due to slight mechanical issues. A source described it as a "minor technical issue" and that the first lady was "fine".
One of the crew members told NBC News that a communications unit on the plane overheated, but the White House has not immediately confirmed that report.
Mrs. Trump was traveling to Philadelphia to visit Thomas. The first lady boarded a separate smaller aircraft soon afterwards and continued forward with her trip.