• ARINC 429, CSDB and analog tuning capabilities available providing various installation options
• Pro Line II CTL-32G provides diagnostic readout and wire-saving serial tuning
• Meets ICAO Annex 10 FM immunity requirements (DO-195/196)
• Conventional analog and serial digital outputs provide compatibility with current aircraft and equipment as well as long-term compatibility with future systems
• Full-time monitoring of more than ten circuit parameters reduces the possibility of an undetected failure
• Digitally controlled AFC gives added protection against interference
• New techniques improve performance, including reduced comm/nav interference
• Maximum use of digital circuitry ensures a lifetime of consistent and stable performance throughout environmental extremes
• Concentrated design effort and fewer parts bring greater reliability than previous-generation navigation receivers

The VIR-32/33/432/433 Navigation Receivers bring the advantages of advanced technology to a fully digital navigation receiver. Now a single version of the radio offers a variety of installation options. It also replaces different versions of predecessor radios.

To improve performance, the VIR features a single crystal and simplified frequency conversion. Digital automatic frequency control centers the received signal precisely in the passband for protection against interference.

The VIR-32/33 is controlled by either a wire-saving digital signal from the Pro Line II CTL-32G or by an analog two-out-of-five control. The VIR-432/433 is controlled by either an ARINC 429 signal from a controller or by a CTL-32G. With a CTL-32G, the radio's self-diagnostic tests are enabled by the self-test button and displayed on the control.

A major advantage of the VIR is that a single version offers a variety of options that depends on how the radio is wired during installation.

For example, one such strap option for helicopter applications is filtering the output to reduce the effect of rotor modulation. Different filtering parameters are activated by connecting power to different pins of the VIR. The radio's microprocessor detects which pin is receiving the power. It uses that information to include or not include rotor mod filtering in the signal processing. This is an important convenience for fleets with a mix of rotary and fixed-wing aircraft, because a single unit can replace either version of a predecessor radio.

Another strap option affects how the instruments respond to self test. Instead of the normal down/right command, a strap option added during installation provides an up/left indication. A strap option may be used to permit the glideslope deviation bar and flag to remain in view when tuned to a VHF omnidirectional radio range.

Once installed, a single VIR can easily transfer from aircraft to aircraft and automatically produce the operational characteristics required for each aircraft.