ALSF I, Dual Mode ALSF II/SSALR, SSAL Approach Lighting Systems
Approach Lighting Systems
Approach lighting systems provide landing approach guidance for pilots. Several different configurations are available:
ALSF I (Approach Lighting System with Sequenced Flashing Lights) is used on Category I runways during instrument landing approach to align the aircraft with the centerline of the runway and to establish vertical orientation. Up to twenty-one white lights create a sequential strobing flash pattern that rolls toward the runway threshold.
The Dual Mode ALSF II/SSALR approach lighting system allows Category II runways to operate in either the full ALSF II mode or in the economical SSALR mode, depending on weather conditions.
ALSF II (Approach Lighting System with Sequenced Flashing Lights) mode is used on Category II runways during instrument landing approach to align the aircraft with the centerline of the runway and to establish vertical orientation. Up to 174 steady burning white lights serve as a reference plane, and two rows of red side row barrettes increase the pilots horizontal perception. Up to twenty-one white lights create a sequential strobing flash pattern that rolls toward the runway threshold. Three intensity settings allow the approach to be used under changing weather conditions.
SSALR (Simplified Short Approach Lighting System with Runway Alignment Indicator Lights) mode is used during instrument landing approach to align the aircraft with the centerline of the runway. The white steady burning lights of the ALSF II are greatly reduced to conserve power under improved visibility and the side row barrettes are not powered. Up to sixty-three steady-burning lights are used to create a reference plane, and up to eight lights create a sequential strobing flash pattern that rolls toward the runway threshold. SSAL (Simplified Short Approach Lighting System) is available.
A 6.6a series circuit powers each approach system. This provides for greater dependability, increased control, decreased maintenance, improved efficiency and lower installation costs.
MALSR Components:
Threshold Fixtures
Green lights that mark the beginning of the runway and may be semiflush FAA L850E (ZA485, 2@105w) or elevated FAA E982 (ZA426, 150w).
Steady-burn Lights
Clear lights that form a reference plane to aid in aircraft alignment with the runway and may be semiflush FAA E2491 (ZA480, 3@105w) or elevated FAA E982 (ZA420, 150w).
Sequence Flasher Fixtures
White lights that create a sequential strobing flash pattern that rolls toward the runway threshold. May be mounted on frangible masts or frangible couplings. FAA L849, Style A and E (FTS 8121 voltage-powered, FTS 8321 current-driven). A semiflush fixture is now under development.
Fiberglass Frangible Approach Mast
These low impact resistant (LIR) support structures are available in 6 ft to 128 ft heights to provide a high intensity guidance system in the clear zone. They are the only masts that are fully compliant with FAA-E2702 specs.
Constant Current Regulator
A single 6.6a L828, 15kw saturable reactor regulator can power the entire approach system. All lights will have the required three intensity settings.
Series Isolating Transformer
FAA L830 rubber encapsulated series isolating transformers are waterproof for above ground, pull pit or ground burial installation.
L823 Connector Kits
Primary and secondary connector kits provide strong waterproof connections between components.
