> For the complete documentation index, see [llms.txt](https://docs.miltechsimulations.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.miltechsimulations.com/miltech-fighters-m2k-c/aircraft-and-systems/navigation-and-communication-systems/bearing-distance-heading-indicator-bdhi.md).

# Bearing Distance Heading Indicator (BDHI)

<figure><img src="https://3365625263-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FHntsqr92bX4SUTi9qW0H%2Fuploads%2FJmFKnVDrnBGYp57L26RF%2Fimage.png?alt=media&amp;token=835d7409-40f1-4af4-a883-34e18cc9c242" alt="" width="563"><figcaption><p>Bearing Distance Heading Indicator</p></figcaption></figure>

1. **Heading Selector:** Selects heading, used by Autopilot NAV Mode
2. **Heading Bug:** Displays selected heading.
3. **Small Needle:** Always displays bearing to the VOR Station selected.&#x20;
4. **Large Needle:** Displays bearing to navigation source as selected by the Mode Selector knob. For example, if NAV is selected on Mode Selector, bearing displayed will correspond to the INS Waypoint.&#x20;
5. **Distance Drums:** Provides distance, in nautical miles, to navigation source as selected by the Mode Selector knob.&#x20;
6. **Mode Selector:** Selects the navigation source
   1. NAV CV: Provides bearing and distance to tuned VOR
   2. NAV: Assuming the INS System is aligned, and a valid waypoint is entered and selected, it will provide bearing and distance to this waypoint
   3. TAC: Provides bearing and distance to tuned TACAN Station
   4. VAD: Not Modeled
   5. RHO: Not Modeled
   6. THETA: Not Modeled
   7. TEL: Not Modeled

## VOR and TACAN Selector Panels

<figure><img src="https://3365625263-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FHntsqr92bX4SUTi9qW0H%2Fuploads%2Fu1gdTEFhsR2HzgPJmtNR%2Fimage.png?alt=media&amp;token=008edaca-ea15-4208-be76-8cc2670064cf" alt="" width="563"><figcaption><p>VOR/ILS and TACAN Panels</p></figcaption></figure>

1. **VOR/ILS Frequency Selected Drums**
2. **VOR Mode:** AUTO/Manual, no sim function
3. **VOR Frequency Selector Knob,** Integer Part
4. **VOR Frequency Selector Knob,** Decimal Part
5. **TACAN Channel Selector Knob,** Hundreds and Tens
6. **TACAN Mode Selector:** OFF/REC/TR/AA
7. **TACAN Channel Selector Knob,** Units
8. **TACAN Channel Selected Drums**
9. **TACAN X/Y Mode Switch**


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