> For the complete documentation index, see [llms.txt](https://docs.flightsim-studio.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flightsim-studio.com/tecnam-p2012/aircraft-flight-manual/section-8-supplements/gcu-477-fms-keyboard.md).

# GCU 477 FMS KEYBOARD

This section contains supplemental information to operate, in a safe and efficient manner, the aircraft when equipped with GCU 477 FMS Keyboard.

## LIMITATIONS

Regardless of the flight plan source, obstacle clearance and adherence to airspace constraints remains a pilot’s responsibility.

In case of malfunction observed within GCU 477 FMS Keyboard, flight crew must switch OFF immediately this system pulling out the relevant circuit breaker.

## EMERGENCY PROCEDURES

{% content-ref url="/pages/SaZGNh6uRLzLcBYqW60P" %}
[Section 3 - Emergency Procedures](/tecnam-p2012/aircraft-flight-manual/section-3-emergency-procedures.md)
{% endcontent-ref %}

## NORMAL PROCEDURES

{% content-ref url="/pages/kkcTRn3ELNHM6bjwmnt7" %}
[Section 4 - Normal Procedures](/tecnam-p2012/aircraft-flight-manual/section-4-normal-procedures.md)
{% endcontent-ref %}

## PERFORMANCE

{% content-ref url="/pages/t2OFLxJDU69bp1BSN299" %}
[Section 5 - Performance](/tecnam-p2012/aircraft-flight-manual/section-5-performance.md)
{% endcontent-ref %}

## DESCRIPTION

The GCU 477 Line Replaceable Unit (LRU) provides alphanumeric, softkey and flight planning functions keys used to interface with the Garmin G1000 Integrated Flight Deck. In addition, the GCU 477 provides COM/NAV tuning capabilities.

<figure><img src="/files/3AVPymCDCD9fubGqf5E5" alt="" width="563"><figcaption><p>GCU 477 FMS Keyboard</p></figcaption></figure>

The system is electrically connected to the LH BUS and it is protected from over current by means of a breaker (5A) located in the breaker panel.

### INPUT MODES

There are 4 input modes that perform different functions depending on which mode is activated.

* **FMS** - MFD/PFD general input
  * Typing on keypad will input the key to active input box on MFD/PFD.
* **COM** - COM standby frequency input
  * Typing on num keypad will activate standby frequency edit mode and input the key.
  * Pressing COM key will toggle tuning box to COM 1/2.
  * Pressing swap key will swap COM active and standby frequency.
* **NAV** - NAV standby frequency input
  * Typing on num keypad in will activate standby frequency edit mode and input the key.
  * Pressing NAV key will toggle tuning box to NAV 1/2.
  * Pressing swap key will swap NAV active and standby frequency.
* **XPDR** - Transponder code input on PFD
  * Typing on num keypad will input the key to Transponder code edit box.

### VIDEO TUTORIAL

{% embed url="<https://youtu.be/3pOWUCCyeO8>" %}


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