Shining the Green Laser: A Detriment to Flight Safety
A cheap green laser pointed at a landing airplane can light up the whole cockpit and blind the pilot at the worst moment. Here is why it is so dangerous.
Marius StefanTechnology Manager2 min read
A green laser pointer costs very little. In India you could buy one almost anywhere for around Rs 800, which is less than US$20. Its beam is strong, and it loses very little power as it travels through the air. It is strong enough to damage the retina of an eye and leave a person blind for life.
Why pilots see the worst of it
Aircrew are the ones who see these lasers misused most. When an airplane flies low on its approach to land, some people on the ground get a thrill from pointing the beam straight at the cockpit. For the person holding the laser, it is a few seconds of fun. For the crew in the air, it is anything but.
The beam grows as it travels
The first problem is that the beam spreads out slightly as it moves through the air. What looks like a thin pencil beam to the prankster on the ground becomes a huge patch of green light for the pilot, about 5 kilometres (2.7 nautical miles) out on approach.
Pilots have also reported that the light scatters when it hits the windshield. It lights up the whole flight deck and pulls the crew's attention away from flying the airplane.
Blinded at the worst moment
The second problem is the strength of the light. It can blind a pilot for a short time or for good, and the risk is highest on a night approach.
- If green light floods the cockpit and scattered light reaches the pilot's eyes, their vision is affected for a while. The pilot can lose sight of the runway and the approach lights. The airplane may then sink below its flight path and hit the ground or buildings short of the runway.
- If the beam hits the pilot's eyes directly, it can blind them for life. The danger right away is losing control of an airplane that may carry more than 150 passengers. The long term cost, even if the other pilot lands safely, is that the injured pilot may never fly again.
Spread the word
Most people who do this mean it as a joke and do not understand the danger. Telling others about the risk is one of the best ways to stop a threat to flight safety that keeps growing. The FBI has also published videos explaining why pointing a laser at an aircraft is so dangerous.
