The Whelen 01-0771424-20 is a PAR-36 LED landing light designed as a direct drop-in replacement for traditional 28V sealed-beam landing lamps (such as GE 4505, 4591, 4594, 4596). It is part of Whelen’s Parmetheus LED series and is widely used in general aviation aircraft to modernize landing and taxi lighting systems.

This model has been superseded by newer variants in the Parmetheus Plus line (notably the 01-0771833-20 series), which offer improved efficiency and performance, but it remains a recognized baseline design for PAR-36 LED landing light upgrades.

Its primary features include:
28V DC LED landing light for aircraft exterior lighting systems
PAR-36 form factor (direct replacement for sealed-beam lamps)
Drop-in installation for existing landing light housings
High-intensity forward illumination for runway visibility
Lower power consumption and longer lifespan than halogen equivalents
FAA-PMA approved aviation lighting component
Vibration-resistant, sealed LED construction for aircraft environments
Compatible with common general aviation aircraft landing light mounts

This type of LED landing light is used to improve visibility during landing, takeoff, and taxi operations while significantly reducing maintenance needs compared to traditional halogen PAR-36 lamps.