Quick Answer: What Is Obs In Aviation?

What is aircraft OBS?

The courseline is selected by turning an “omni bearing selector” or ” OBS ” knob usually located in the lower left of the indicator. It then shows the number of degrees deviation between the aircraft’s current position and the “radial” line emanating from the signal source at the given bearing.

What is the difference between HSI and CDI?

A standalone CDI (Course Deviation Indicator) is an instrument that shows your deviation from a VOR radial that is selected using the OBS (Omnibearing Selector) knob located on the instrument itself. An HSI (Horizontal Situation Indicator) is an entirely separate instrument that combines a CDI and a heading indicator.

How do you read CDI in aviation?

On the CDI instrument just read the number displayed on the compass card (±90° of the radial). In the left figure above, the shortest path to join the VOR radial is 340° (=070°-090°) (blue straight arrow). The VOR is located in the sector between 340° and 070° as we are in the TO region.

What is the difference between a standard VOR and HSI?

On a conventional VOR indicator, left–right and to–from must be interpreted in the context of the selected course. When an HSI is tuned to a VOR station, left and right always mean left and right and TO/FROM is indicated by a simple triangular arrowhead pointing to the VOR.

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What does RNAV stand for?

RNAV stands for Area Navigation. RNAV: Capability to fly any desired flight path, defined by waypoints such as geographic fixes. (LAT/LONG) and not necessarily by ground navaids.

What does OBS stand for?


Acronym Definition
OBS Open Broadcaster Software (live streaming software)
OBS Observed
OBS Obviously
OBS Obsolete


What is a slaved HSI?

The ST-180 Horizontal Situation Indicator ( HSI ) system combines a magnetically slaved gyroscopic compass with a VOR/Localizer and glideslope display. The resulting instrument display provides the pilot with a pictorial of the aircraft position and heading relative to the selected VOR/GPS or Localizer course.

What is CDI and OBS?

A course deviation indicator ( CDI ) is an avionics instrument used in aircraft navigation to determine an aircraft’s lateral position in relation to a course. The OBS (Omni Bearing Selector) knob is on the CDI, it is not its own instrument.

What makes an HSI easier?

By switching the HSI to GPS mode, the course needle and CDI indicate position relative to the GPS course. Any way you look at it, if you’re navigating by GPS, VOR, or making an ILS approach, an HSI makes the job easier, and that should mean a safer flight.

What is Obi aviation?

Omni Bearing Indicator ( OBI ) – Used for VOR navigation and the cheapest way to do so, has a manual compass card that selects the desired VOR radial and a CDI needle to provide a steering aid to place the aircraft on that radial, with a “TO/FROM” indicator to resolve directional ambiguity.

How do you read HSI aviation?

In the HSI instrument, the TO/FROM indicator (yellow triangle) always points toward the VOR direction. The course radial indicator (black arrow) represents the radial direction from the VOR. The course deviation bar (red) is located exactly in function of the aircraft heading.

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How is an HSI powered?

HSIs can be driven by iron gyros or by electronic (digital) gyros. If iron gyros, those gyros can be spun by electricity or by vacuum. The displays can be electronic (EHSIs) or mechanical. Finally, the HSI compass card can be slaved to a magnetic sensor or non-slaved like your basic heading indicator.

What is the purpose of HSI?

HSI’s mission is to investigate, disrupt and dismantle terrorist, transnational and other criminal organizations that threaten or seek to exploit the customs and immigration laws of the United States.

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