Aviation obstruction lighting

Aviation obstruction lighting is used to enhance the visibility of structures or fixed obstacles which may conflict with the safe navigation of aircraft.

Obstruction lighting is commonly installed on towers, buildings, and even fences located in areas where aircraft may be operating at low altitudes.

In certain areas, some aviation regulators mandate the installation, operation, color, and/or status notification of obstruction lighting.

For maximum visibility and collision-avoidance, these lighting systems commonly employ one or more high-intensity strobe or LED devices which can be seen by pilots from many miles away from the obstruction.

In the United States and Canada, there are several types of lights: Traditionally, red lamps (or beacons) use incandescent filament bulbs.

LED-based lamps have a significantly longer lifespan than incandescent bulbs, thus reducing maintenance costs and increasing reliability.

[citation needed] It is common to find structures using white xenon flashers/white strobes during the daytime, and red lights at night.

The FAA-mandated flash pattern is middle, top, and bottom to provide "a unique signal that pilots should interpret as a warning that catenary wires are in the vicinity of the lights.

The second approach is based on Faraday's law of induction involving magnetic flux flowing through a circuit which energizes the warning light.

A simple and cost-effective solution to this problem is installing marking lights directly on the wires, but there are significant technical difficulties to low-cost power extraction from a distribution system which carries high voltages and wide-range AC current.

The second approach is based on Faraday's law of induction involving magnetic flux flowing through a circuit which powers the warning light.

Antenna towers and masts often also have other aircraft warning features located at equal distances along their height and at their tops.

Emley Moor transmitting station using a red warning beacon
Aircraft warning lights at the Mannheim telecommunications tower, in the background the bright torchlight of a steam cracker, in the distance warning lights from wind turbines
Structure using a white strobe
Structure using a Red/White Strobe
Closeup of an aircraft warning light on top of a highrise in Changzhou, China
Closeup of an aircraft warning light on top a factory facilities
Structure using high-intensity white lights and a medium-intensity white strobe
Warning light at 216 feet (66 m) atop the WRLF FM antenna
Aircraft conductor marking lights warning
Example of a magnetically powered beacon based on a Rogowski coil (similar to a current transformer ). This solution is usually intended for medium and high voltage lines up to 440 kV, but inductive coupling devices are able to work on any AC at 50 Hz or 60 Hz, from 15 up to 2000 Amps.