PRF-4M

Landing and taxi modes

The unit works with a dual-mode lamp-light. The landing filament provides a higher-intensity, comparatively narrow beam, while the taxi filament produces wider illumination for ground movement. An electric mechanism moves the light from the retracted position and sets the working angle.

Aircraft application

The PRF-4M was used on Soviet-designed aircraft. Il-76 technical documentation identifies these lights in the nose and wing-tip areas. Application must be checked for the particular aircraft modification, wiring configuration and installed lighting equipment.

Selection checks

Compare the PRF-4M designation, 27 V supply, 345 × 276 × 102 mm dimensions, mounting points and connector. Confirm the required lamp-light and the ratings for both operating modes. A nameplate photograph helps distinguish the unit from the separate PRF-4MP version.

Retractable-light construction

In the retracted position, the PRF-4M reduces projection of the lighting unit beyond the aircraft contour. When selected, the electromechanical mechanism moves the light into its working position and the deployment angle determines beam direction. Replacement inspection therefore covers the motor, gearbox, end positions, clutch, housing sealing and power circuit as well as the lamp itself.

The landing and taxi filaments have different ratings and produce beams for different tasks. A visually similar light must not be treated as interchangeable without checking the drive and control circuit; matching voltage and approximate dimensions alone are insufficient.

Related lamp-lights

Confirm the lamp-light version for the PRF-4M against the aircraft documentation. Related sources are listed under LFL and LFSM aircraft lamp-lights. The Wikipedia article on aircraft lighting provides general background on landing and taxi illumination.

Supply

Aviamisto supplies the PRF-4M on a pre-order basis. Include the quantity, aircraft type and documentation requirements in the enquiry. Price, condition, completeness and lead time are confirmed in the quotation.