KPP-LK / 1273LK

Attitude indication through KPP-LK

The KPP-LK indicator displays the aircraft position relative to the true horizon. It provides visual indication of roll and pitch, allowing the pilot to monitor spatial orientation of the aircraft during normal flight, maneuvering and instrument flight conditions. The pitch scale shows the aircraft’s nose-up and nose-down attitude, while the roll scale provides circular indication with marked angular references. The instrument is used as one of the primary cockpit flight references and is normally placed in the central flight instrument area in front of the pilot.

Flight director function of 1273LK

The 1273LK instrument includes movable command bars used for director flight control. These bars show the pilot the direction and magnitude of required control inputs for maintaining or acquiring the selected flight path. Command signals may come from the automatic flight control system, trajectory control system, landing radio system or onboard navigation computer, depending on the aircraft configuration. The instrument itself does not calculate the flight path; it displays received command information and allows the pilot to follow the director commands visually.

KPP-LK as a remote indicator

KPP-LK is not an autonomous gyro horizon. It does not contain the main gyro reference used to generate aircraft attitude data. Roll and pitch signals are supplied from external sources such as a central gyrovertical, inertial system or onboard flight-navigation computer. Command signals are supplied from the automatic control or trajectory control system. This means that correct operation of the instrument depends on external attitude sensors, power supply, wiring, signal validity and associated control computers. Failure flags on the display warn the crew when selected signals are absent or unreliable.

Cockpit installation of KPP-LK

The KPP-LK is installed on pilot instrument panels in the central flight instrument area. On aircraft with two pilot stations, similar indicators may be installed in front of the captain and copilot. The instrument fits into a standard panel-mounted cylindrical housing with a square front flange. It is normally placed in the main “T” layout of flight instruments together with navigation indicators. Associated attitude sensors and flight control computers are installed separately in avionics compartments, radio equipment bays or technical racks, depending on aircraft type and layout.

Identification and ordering of KPP-LK / 1273LK

KPP-LK belongs to the 1273 series of Soviet / Russian command flight indicators, which also includes related versions such as KPP-K, KPP-MK and KPP-PKE. Before ordering, the exact designation, aircraft type, system configuration, condition and documentation set should be confirmed. The unit may be required for cockpit restoration, flight instrument replacement, overhaul support or spare parts stock. For acceptance, it is useful to clarify passport availability, test records, connector configuration, failure flag operation, lighting circuit condition and compatibility with the aircraft’s gyrovertical and flight director systems.

Related instruments: PKP-77M, NPP-MK 1485-MK, PNP-72-12. These links are grouped by type and system and do not indicate interchangeability.