Retention of items of mass in passenger and crew compartments
Read the official ruleThis regulation requires airlines to secure loose items in passenger and crew compartments so they don't become dangerous projectiles during an emergency landing. Specifically, airlines must have systems to prevent galley equipment, serving carts (when not in use), and crew baggage from shifting around under the forces that occur during the emergency landing conditions the aircraft was certified to withstand.
In practice, this means items must be properly stowed in secured compartments, latched in place, or restrained with appropriate tie-downs or other devices. An unsecured coffee pot, serving cart, or crew bag could seriously injure passengers or crew if it breaks loose during a hard landing or crash. The securing methods must be strong enough to handle the specific G-forces the aircraft type was tested for during certification. This is why you'll see flight attendants carefully stowing all galley items and their bags before takeoff and landing.
*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*