Maximum Luminous Intensity of LED-lighted X signs for Airport Runways

Published

June 12, 2024

Author(s)

Yoshihiro Ohno, Maritoni Litorja, Carl Miller

Abstract

This is a report for Inter-agency agreement 693KA9-18-N-00023 "Maximum Luminous Intensity for LED Signaling in an Airport Environment" by Federal Aviation Administration (FAA) and National Institute of Standards and Technology (NIST). The LED-based lighted X signs recently introduced at many airports are perceived too bright by pilots, causing glare and making it difficult to recognize the X character. The objective of the study is to determine the acceptable level of maximum luminous intensity of LED-lighted X signs that maintains clear visibility of the lighted X sign. A theoretical study with literature review was first made (Part 1). Then vision experiments were conducted using pilots as subjects (Part 2). The methods and results of these studies are reported.

Citation

NIST Interagency/Internal Report (NISTIR) - 8321

Report Number

8321

NIST Pub Series

NIST Interagency/Internal Report (NISTIR)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.IR.8321

Local Download

Keywords

airport, signaling, lighted X sign, luminous intensity, glare, visibility

Citation

Ohno, Y. , Litorja, M. and Miller, C. (2024), Maximum Luminous Intensity of LED-lighted X signs for Airport Runways, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.8321, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930682 (Accessed November 25, 2025)