PNP-72-12

Navigation information displayed by PNP-72-12

The PNP-72-12 combines the functions of several separate cockpit indicators. It can display current heading, selected course, deviation from the selected flight path, bearing to a radio navigation station, distance to a selected beacon, and course / glide path deviation during approach. This allows the pilot to read several navigation parameters from one instrument instead of monitoring separate heading, radio magnetic, bearing and distance indicators. The display principle is based on a “view from aircraft to ground” presentation, with a moving heading scale.

PNP-72-12 as a combined electromechanical instrument

The PNP-72-12 is an electromechanical, remote-following aviation indicator. It receives analog electrical signals from onboard sensors and navigation systems, then converts them into movement of pointers, scales and deviation indicators. The instrument uses channels based on sine-cosine transformers and operates with 400 Hz signal circuits. This design makes the unit suitable for integration with classic Soviet / Mil helicopter navigation complexes where navigation data is transmitted to cockpit instruments through analog electromechanical channels.

Cockpit installation of PNP-72-12

The PNP-72-12 is installed on the instrument panels of the flight crew. On Mi-26 and Mi-26T helicopters, several PNP-72-12 indicators may be installed: on the captain’s panel, on the co-pilot’s panel and at the navigator’s workstation. In this layout, the unit is normally positioned in the central part of the flight instrument zone, often below the attitude director indicator. On Mi-8 and Mi-17 modifications equipped with suitable flight and navigation complexes, the PNP-72-12 may be installed on the left and right pilot panels and can replace older heading indicators such as UGR-4UK, depending on configuration.

PNP-72-12 during navigation and approach

In flight, the PNP-72-12 helps the crew maintain the required course and monitor deviation from the planned flight path. When working with radio navigation stations or beacons, the instrument displays bearing and distance information. During approach, it can show position relative to course and glide path channels, allowing the pilot to monitor lateral and vertical deviation. The exact indication logic depends on the connected onboard systems and aircraft configuration, but the purpose remains the same: to present essential navigation data in one cockpit instrument.

Built-in test control of PNP-72-12

The PNP-72-12 has a built-in operational test system that allows the crew to check the main scales and indicators directly on board. Test control can verify the operation of heading, azimuth, range and glide path indication channels. This is important because the instrument is used as part of the pilot’s navigation reference. Before flight or during required cockpit checks, the test function helps confirm that the main pointers and display elements respond correctly to test signals.

Supply and identification of PNP-72-12

When ordering or replacing the PNP-72-12, the full designation and modification should be stated clearly. The modification PNP-72-12 is associated with registration number P-06121 and is used on Mi-26 and selected Mi-8 / Mi-17 series helicopters depending on the installed navigation complex. For aircraft installation, the unit should be checked by part number, aircraft equipment list, wiring diagram, connector type, passport documentation and compatibility with the onboard flight and navigation system.

Related instruments: PNP-72-14, PNP-72-4M, PNP-72-15. These links are grouped by type and system and do not indicate interchangeability.