Figure 1-8. UHF AN/ARC-159V Control Panel

CHAPTER ONE

INSTRUMENT FLIGHT RULES WORKBOOK

Figure 1-8 UHF AN/ARC-159V Control Panel

The ARC-159V, like most UHF transceivers, has a four-position function switch. The positions

are as follows:

OFF The radio is disconnected from the aircraft's power supply.

MAIN Transmit and receive on the selected frequency set in the radio.

BOTH Same as No. 2 plus the pilot is able to receive GUARD transmissions on

243.0 MHz.

ADF Automatic direction finding. (Not used in the T-34C.)

The UHF frequency band is the primary choice for military voice communications.

107. TACTICAL AIR NAVIGATION (TACAN)

While civilians normally use VOR for air navigation, the military has developed another

navigation system called TACtical Air Navigation, or TACAN. The TACAN in the T-34C is

designated TCN-40.

Although VOR was a great improvement over earlier navigational systems, a gap still existed in

the information available when navigating. The TACAN system was developed to fill this gap

by providing information needed for precise geographical fixing of the aircraft's position. In

addition to the displayed bearing information, TACAN adds a continuous display of range

1-12 INTRODUCTION TO AIRBORNE NAVIGATION AND COMMUNICATIONS

EQUIPMENT AND PRINCIPLES OF OPERATION