What is the purpose of the stable platform?

• A. To keep accelerometers level relative to Earth's surface so that only aircraft movements are detected
• B. To transmit signals to satellites
• C. To measure outside weather
• D. To cool the accelerometers

Answer: (A)

The stable platform’s job is to keep the accelerometers oriented with respect to Earth so they respond only to the aircraft’s true linear motions. By mounting the sensors on a gimbaled, level frame, the platform cancels out the aircraft’s rotations (roll, pitch, yaw), so the gravity vector stays steady in the platform’s coordinates. This way the accelerometer readings reflect actual accelerations of the aircraft, not changes in orientation or gravity direction. The other options describe functions (signal transmission, weather sensing, cooling) that aren’t about maintaining proper accelerometer orientation for inertial sensing.