Product Identification

L-849(L) REIL – Runway End Identifier Light
L-859(L) ODAL – Omni Directional Approach Light

Compliances (Current Editions)

FAA: AC 150/5345-51, EB67, ETL Certified
Canada: TP 312 5th Edition

Key Features

- Low annual energy costs
- Long-life LED for years of service
- High, medium and low intensity
- Primary/Secondary system operation
- Field programmable sequence timing
- Meets photometric beam requirements for MALSR, SSALR, and ALSF-I/II - Contact ALC Sales for product information
- No power adapter required
- True RMS current sensing
- Uni-directional or Omni-directional
- 50 or 60 Hz
- Flash monitoring
- Elapsed time meter
- Use two (2) L830-4 100W Isolation Transformers

General Information

The Airport Lighting Company (ALC) L-849(L) REIL and L-859(L) ODAL are voltage-powered or current-driven
systems. L849(L) System will consist of two Optical Flashheads (OFH) co-mounted to a Primary Cabinet Unit (PCU)
and Secondary Cabinet Unit (SCU). L859(L) ODAL System will consist of seven units with five sequentially flashing
OFHs and two synchronized OFHs.

The system can operate as FAA Style A, B, C, D, E, or F (L-849 or L-859). The OFHs are used to light the threshold
(approach end) of a visual or instrument non-precision runway and provide guidance to pilots during approach for
landing.

FAA Style | Flashhead Type | Intensities
A | Unidirectional | High
B | Omnidirectional | High
C | Unidirectional | Low
D | Omnidirectional | Low
E | Unidirectional | Low, Medium, High
F | Omnidirectional | Low, Medium, High

The OFHs receive flashing and other operating commands from the PCU and send monitored status information
in return. Selected operating parameters are shown visually on the display inside the PCU. The SCU will only have a
power supply, no user interface control board.

Operation is typically automatic, but flash intensity functions can be set to Maintenance mode for testing purposes.
The OFHs flash simultaneously upon a single command from the Universal Controller Card (UCC) inside the PCU.
The flash rate is 120 flashes per minute (FPM) for A, C, & E systems, 60FPM for B, D & F systems. See below table for
system information.

This beam coverage is formed by the composite effect of an array of high-performance, white LEDs.

 
The LED array is monitored in such a way that a failure exceeding a certain number of LEDs at random locations, will
turn on an alarm signal light and cause an alarm relay to operate. The alarm relay is for external remote distribution.
Fault notification is generated because of failure within the lighting system. The system fault is shown on the OLED
screen within the PCU. A dry contact alarm is provided for remote monitoring.

 

Theory of Operation Overview

The ALC LED REIL is a microcontroller-based system designed for reliable operation. Each omnidirectional flashhead (OFH) features optically enhanced, high-performance LEDs arranged within a reflector cone for unidirectional configurations or specialized lensing for omnidirectional ones. The power and control unit (PCU) incorporates a single Universal Controller Card (UCC) that handles all input and output functions, while an RS-485 data bus enables communication between the PCU and the system control unit (SCU). Each flashhead communicates directly with the UCC to report its operational status and is uniquely identified by an address code for proper data tagging.

A low-capacitance data transmission line, compatible with RS-485 drivers and receivers, supports reliable communication at the system's baud rate over distances of up to 4000 feet; for this purpose, a #18-AWG twisted-pair shielded cable suitable for direct burial is recommended. Although the flashheads communicate solely with the UCC, the UCC itself includes external connections for primary power, remote switching, and a remote alarm activation circuit—lines that may be exposed to voltage surges or other electrical disturbances.

The internal electronics and flashhead are powered by either a wide-ranging AC input of 95–264 VAC at 50/60 Hz or a constant current ranging from 2.8 A to 6.6 A. During operation, each OFH continuously scans its LEDs to monitor temperature, voltage, and flash performance. If any head detects an operating condition that falls below FAA EB-67D prescribed safe levels—such as more than 25% failed LEDs in a single head, an incomplete column of LEDs, or an incomplete row—an alarm signal is generated. In such cases, a failsafe alarm relay (which closes its contacts upon failure) is also activated, providing a means for remote alarm signaling.

Airport Lighting Company | L-849(L) REIL Runway End Identification LightL-859(L) ODAL OMNI Directional Approach Light