Flight Alarm The FLIGHT ALARM is a dual function unit. It provides a full time flight pack battery monitor and a downed aircraft locator. Battery Monitor The FLIGHT ALARM utilizes a microprocessor with an internal analog to digital converter and a precision voltage reference to monitor the battery voltage. The unit measures the battery voltage 50 times a second, should the voltage drop below 4.720 +/- 0.025 volts (5.860 volts for 6.0 volt systems) the alarm will sound. The FLIGHT ALARM automatically determines the system voltage when the aircraft is turned ON. The alarm sounds a pulsing high intensity (95=db @ 3 feet) audible alarm of 2 pulses per second if battery is low. Aircraft Locator In addition, the FLIGHT ALARM monitors the receiver output to trigger the same alarm to help locate a downed aircraft. In this mode the alarm sounds at 1 pulse per second. The FLIGHT ALARM is available for either AM/FM or PCM systems. In the AM/FM mode, just plug the unit into any unused channel. The alarm will sound as soon as the transmitter is turned OFF. The PCM mode works differently, as the PCM receiver does not stop sending servo signals when the transmitter is turned OFF. For PCM operation, select a switch controlled channel, like landing gear or similar. With the transmitter ON the alarm can be turned ON and OFF by moving the channel switch. If your aircraft goes down, flip the channel switch to the alarm position. The transmitter may now be turned OFF and the alarm will continue to sound. After the aircraft is found return the switch to its' original position. Should you have a problem with the PCM mode set up, please call. For installation and operation instructions click HERE