Angelina Jolie and son Maddox
Between her visits this week to embattled zones in Pakistan and Sierra Leone – and amid rumors still going strong about a relationship with Brad Pitt – Angelina Jolie stayed grounded by just playing Mommy, as she took time with 3-year-old son Maddox to check out some real high fliers at London's Royal Air Force Museum.
"Her hair was hanging down over her face. She looked very slim and svelte," museum worker Ellena Booth tells PEOPLE. "Visitors kept coming up to me and saying, 'Isn't that Angelina Jolie?' But no one bothered them, everyone left them alone."
Booth said mother and son sat in the two-seat training helicopter on display, "then went to the 'Drop Zone,' where there's a simulation of an aerial drop. ... her son was running around like mad."
Later, Mom and Maddox (whom United Nations goodwill ambassador Jolie adopted in Cambodia), toured the Bomber Hall, which offers visitors the chance to get close to a variety of authentic 20th century combat aircraft. They also visited the museum's Milestones of Flight exhibit, a modern presentation of 100 Years of Aviation.
And then? Shopping in the museum store. As store manager Lewis Shelley tells PEOPLE: "Her little boy really seemed to be enjoying himself."