What is an OBS in aviation?
Just so, what is an HSI in aviation?
The horizontal situation indicator (commonly called the HSI) is an aircraft flight instrument normally mounted below the artificial horizon in place of a conventional heading indicator. It combines a heading indicator with a VHF omnidirectional range-instrument landing system (VOR-ILS) display.
Considering this, what is an Omni Bearing Selector?
OMNI BEARING SELECTORS (OBS) The Omni Bearing Selector (OBS) is an integral part of the VOR navigation system. With its attendant VOR converter it allows a pilot to select and determine the radial that he is on and provides an accurate error signal that is proportional to the offset from the intended track.
The horizontal situation indicator (HSI) was designed to eliminate some of the work of using very-high-frequency omnidirectional range (VOR) navigation and instrument landing systems (ILS). The HSI works by combining a VOR/DME receiver and an electrically-slaved heading indicator.