Aviation Dictionary
وسيله يا ابزار دقیق پروازی ژیروسکوپی که وضعیت پیچشی و غلتشی هواپیما یا فضاپیما را نسبت به افق نشان می دهد
A flight instrument that provides the pilot with a visual reference when the natural horizon is not visible. a bar or display, held in a constant relationship with the earth's horizon by a gyro, serves as the reference.