The Audio Panel is generally located at the very top of the radio stack. Its function is to act as a master control for which radio you will listen to and which one you will broadcast on.

Here is how it works:

 As you can see the panel has two rows of push buttons. These control which radio you are listening to and how you listen to them. When you press one of the buttons on the bottom row, for example, Com 1, you will hear Com 1 in your headset. If you press the button for Com 1 on the top row, you will hear Com 1 on the overhead speaker in the aircraft. If you press both at the same time, the sound from Com 1 will be channeled to both your headset and the overhead speaker. 

    Let's say you want to listen to your Com 2 on your headset, you would push the Com 2 button on the bottom row, once you do so it should stay pressed in and that’s it, you're listening to Com 2.

So, that’s for listening, how about broadcasting?   On the right side of the panel you have a switch; in order to broadcast on Com 1, turn the switch to Com 1. Same idea if you want to broadcast on Com 2.

To the left of the Broadcast selector switch, are two push buttons labeled "Auto".  As I wrote above, in order to listen to a radio you need to press one of the Com radios buttons. However, if you push the "Auto" button, and leave all of the other buttons out, as in, not pushed (How's THAT for sophisticated English!), the audio panel will automatically pick up on the com radio that you have selected to broadcast on.  So, using the picture above as an example, if you have the Auto button pushed, and the broadcast selector is on Com 1, you are already listening to Com 1.

Com 1 and Com 2

The Com1 and Com 2 are essentially the same instrument, you just have two of them. Each one allows you to broadcast and receive radio communications as well as setting the frequency for the VOR navigational aid.

            The unit is split in to two, on left the screen is the communication radio while the right side and screen controls and displays the VOR navigation aid frequency. Both sides have the same sets of controls. We will review the controls from left to right.

1. This button controls the volume of the radio and if turned to its full left position, it will shut off the radio unit. (Only the left of these buttons turns the unit on and off) 

          Each VOR station transmits a unique Morse code identifier which allows you to positively identify that you  are indeed                   tuned in to the correct frequency. To listen to the identifier, simply pull outwards on the knob on the Navigation side of                   the unit.

2. This button will swap the standby frequency with the active frequency.

For example:

Before Pressing	After Pressing

3. This set of two knobs, one larger and one smaller in the middle, allows you to change your radio and navigational aid frequencies. The larger knob controls the first three digits before the decimal, and will change the numbers one digit per click.
   

 The smaller knob controls the three final digits after the decimal. The smaller knob changes the numbers in                            increments of .050 Mhz, however, if you pull the knob outwards, towards you, the knob will then change the numbers           in increments of .025 Mhz.

Transponder

The transponder is kind of like the "Santa's Little Helper" of air traffic controllers. The transponder allows the controller to differentiate between aircraft on his radar. This is done by assigning different codes, or "Squawks" to aircraft, once the code is inputted itwill appear on the controller's screen, and instead of being a random blip on the radar, the controller can then effectively monitor you and know where you are. Further more, transponders with what is known as Mode C capability transmit information about the aircraft to the controller, such as altitude. 

            Here is how you use it. On the left of the instrument, you will find a knob with 5 settings:

OFF: The unit is off, no rocket science there.

SBY: The unit is on Stand By mode. In this setting the unit is warming up, but not yet transmitting information.

ON: The unit is on and it is ONLY transmitting the inputted Sqauwk code.

ATL: The unit is on and it is transmitting BOTH the Squawk code and the current altitude of the aircraft.

TST: This button tests the units functionality.

Directly to the right of the knob is a small red light. This is called the "Reply Light". When this light is flashing, it indicates that the unit is being interrogated by ATC radar and is sending information back to the controller.

Below the Reply light there is a small button called the IDENT button. This buttons gives a little boost to your transponders output which enhances your blip on the controllers screen. Often time's controllers will as you to "Ident" in order to help them find you more quickly on their screen. When the controller asks you to do so, simply press the button for 1 second and release.

To the right of the Reply light and the Ident button, is the code selector. Each knob changes the respective digit above it. Most codes are issued by the controller however; there are some special codes that used only at very certain times.

CODE	WHEN THE CODE IS USED
1200	This code is used whenever flying VFR in uncontrolled airspace.
7500	This code notifies Air Traffic Controllers that the aircraft has been hi-jacked
7600	This code notifies Air Traffic Controllers that the aircraft has lost two-way radio capabilities
7700	This code notifies Air Traffic Controllers that there is an emergency aboard the aircraft

Radio Phraseology

A lot of pilots can handle the aircraft beautifully however when it comes time to make a position report or contact a tower, they freeze up. This is probably because two things. They are confused with what to say, and probably more so, are afraid of the embarrassment of saying something that is wrong and doesn’t sound like "The Pro's".  Let me tell you  that there is no need to worry about being embarrassed. I have heard pilots of great big airliners who still can't get a sentence right. In regards to what to say and when, it's simple once you understand its framework.

Let's start with the basics. There is something called the "Phonetic Alphabet". The phonetic alphabet gives each letter a corresponding word. So instead of saying the letter itself, you say the word and this avoids confusion over the radio. Have you ever tried to spell your name over the phone to a customer service agent? We all had have to use words to differentiate between letters like "D as in Dog" or "M as in Mike" to help avoid confusion. The phonetic alphabet does exactly that we pre determined words. Below is a table of the phonetic alphabet.

	Letter / Number	How its said over the radio
	A	ALPHA
	B	BRAVO
	C	CHARLIE
	D	DELTA
	E	ECHO
	F	FOXTROT
	G	GOLF
	H	HOTEL
	I	INDIA
	J	JULIET
	K	KILO
	L	LIMA
	M	MIKE
	N	NOVEMBER
	O	OSCAR
	P	PAPA
	Q	QUEBEC
	R	ROMEO
	S	SIERRA
	T	TANGO
	U	UNIFORM
	V	VICTOR
	W	WHISKEY
	X	X-RAY
	Y	YANKEE
	Z	ZULU
	0	ZERO
	1	ONE
	2	TWO
	3	TREE
	4	FOW-ER
	5	FIFE
	6	SIX
	7	SEVEN
	8	EIGHT
	9	NINER
	10	ONE ZERO

What is my name? How am I called?

Good question. I am sure you can find the answer to that on your driver's license, but let's modify the question a bit; how am I called over the radio? Other pilots don’t know that my name is Ben…

This is when we use what is called a "Call Sign". A Call Sign is your radio name and it is unique to your aircraft. In general aviation, Call Signs are a combination of the aircrafts make and its registration number.

For example, if you are flying a Cessna 172 Sky Hawk, and its registration number is N1377U, your Call Sign would be as follows:  "Sky Hawk 1377U". It would be pronounced: "Sky Hawk ONE TREE SEVEN SEVEN UNIFORM"

If you are flying a Piper Cherokee and your registration number is N83960, your Call Sign would be: "Cherokee 83960". 
It would be pronounced:

"Cherokee EIGHT TREE NINER SIX ZERO"

The registration prefix of "N" is dropped! 

So, what do I say?

Radio communication is a conversation between you and the controller or between you and the other aircraft in the area. You can think of it as a phone call.

When you make a phone call, the first thing you do is say "Hello to the person you are calling". The second thing you do is introduce yourself, who you are and most likely, where you're from. Third thing you do is say what's on your mind, or what it is you plan on doing. 

For example:

 "Hello  Mike,this is Ben, I didn’t leave home yet. I just wanted to let you know that I am coming over in about 10                minutes."

When you make radio calls, your initial call, the one that normally makes pilots freeze up, follows the very same format, except instead of calling your friend; you are calling either the controller or the other pilots.

 For example:

Hello:  "Montgomery Traffic"

                "Lancaster Tower"

Introduce: "Sky Hawk 1377U, 10 miles to the north"

What you plan on doing: "Inbound for landing on runway 14"

                                                 "Would like to transition your airspace"

That’s the initial call.  Radio calls break down into two groups. Those calls made at airports that don’t have a control tower, and those that do.

Uncontrolled airports

Most of your flying will be done at uncontrolled airports. These are airports that don’t have an active control tower making sure that people don’t bump into each other.  This means that we need to be sure to make position reports and announce our intentions to others. We do this on a specially designated Common Traffic Advisory Frequency or CTAF for short.

The framework of the radio call should be as followed:

	Which airport
	Who you are
	Where you are
	What you are planning to do
	Which Airport

  For example:

"Montgomery Traffic, Sky Hawk 1377U is 9 miles to the north,  inbound for landing on runway 14, Montgomery"