Professional Pilot, May 2019

Fitting landing strips with LEDs LED lights at CMH Columbus OH LED bulbs are more desirable because of reduced energy consumption and low maintenance costs FAA has approved LEDs for all airport surface applications except approach lighting systems A viation has a bright future and its not a result of the current job market Incandescent light bulbs the stalwart source of airport illumination since the 1930s are slowly but surely being replaced with Light Emitting Diodes LEDs Many in the industry believe the impetus for the change was the Energy Independence and Security Act of 2007 passed by Congress and signed into law by President George W Bush Although media accounts at the time caused widespread concern about the disappearance of household light bulbs at the retail level the act itself did not ban the use or purchase of incandescent bulbs Rather 52 PROFESSIONAL PILOT May 2019 the legislation specified a broad philosophy of decreasing energy consumption and increasing efficiency Given that a household incandescent light bulb 40 100 watts was so well known and ubiquitous it was an easy target for regulators The act excluded specialty lights like those in appliances but required that the efficiency of all other incandescent bulbs improve by 25 Because LED bulbs are by design more efficient than their incandescent counterparts they represented a natural transition Manufacturers figured out that it was more cost effective to replace rather than re engineer bulbs and responded by flooding the marketplace with LED options while at the same time reducing their incandescent product lines While no ban on incandescent lights existed the changing retail landscape made it seem like one History of the incandescent light bulb A source of light is considered incandescent if it gives off light as a result of being heated The history of the incandescent light bulb goes all the way back to Thomas Edison in 1880 A basic light bulb is created by applying electricity to a thin wire usually made of tungsten The electrical current causes the wire filament to become hot which then glows and gives off light Increasing the amount of current creates more light and vice versa Up to 95 of the electricity used in an incandescent bulb is wasted as heat The other problem is that the thin filament wears out quickly Encasing the filament in an inert gas minimizes the breakdown associated with rapid heating and cooling but its lifespan is still relatively short A halogen lamp represents an improvement from a basic filament bulb in that it makes use of a noble gas like krypton or xenon to achieve a higher level of brightness Again more brightness equates to more radiated heat A beneficial characteristic of halogen is that it interacts with the tungsten atoms if incorporated into a light bulb effectively slowing disintegration of the filament Halogen or quartz halogen lamps are better than basic tungsten filament bulbs when used in airport applications but they still require special transformers cables connectors and regulators to maintain a standardized current to each part of the system for it to function properly Levels of runway illumination FAA specifies 3 levels of runway illumination Low Intensity Runway Lights LIRL Medium Intensity Runway Lights MIRL and High Intensity Runway Lights HIRL The candela cd is the universal scientific standard for measuring luminous intensity brightness It measures the amount of light a source projects in RUNWAY LIGHTING Light Emitting Diodes are more efficient but can cause problems for pilots By Shannon Forrest President Turbine Mentor ATP CFII Challenger 604 605 Gulfstream IV MU2B