Gyro instruments are essential for instrument flight. Aircraft vacuum (or pressure) systems that power these instruments have a high failure rate, and can fail at any time leaving you without the use of these instruments. Tests have shown that gyro instruments can start giving false information within less than 1 min. after a complete vacuum loss. Without the means to instantly recognize this loss of vacuum a pilot may start to respond to a changing aircraft attitude that is incorrect without even knowing it. This can lead to conditions from which recovery is difficult or impossible.
Many aircraft are equipped with backup vacuum systems, however you must first know that your instrument power system has failed before any of these backup systems are engaged. You must "know you have a problem before you have a problem".
The P/N 2044 Volt & Vac Alert consists of a small electronic unit that can be mounted anywhere in the aircraft. It connects to aircraft voltage, instrument power (vacuum or pressure), and the aircraft audio system. A small red light is also mounted on the instrument panel within the pilots normal gyro scan. Should the gyro power fail, the pilot will hear the voice message "CHECK GYROS, CHECK GYROS" directly in his headset. The voice message will sound once, and then the red warning light will illuminate until the problem is fixed. The unit can be used in 12v or 24v aircraft with either vacuum or pressure gyro power systems. It can be installed in pressurized or un-pressurized aircraft.
The P/N 2044 Volt & Vac Alert is sold as a complete assembly with everything necessary for the installation except a 1 amp fuse or circuit breaker.