In two recent incidents in Michigan, a person or persons on the ground pointed green lasers at Coast Guard helicopters, endangering the flights and forcing crews to return immediately to base.

A Coast Guard helicopter was on a training mission at 8:15 p.m. Oct. 17 when the pilot and co-pilot spotted a green laser directed at the aircraft, the Coast Guard said yesterday. They turned the helicopter away and returned to the air station. A similar incident occurred at 8:30 p.m. Oct. 20, in a nearby Township. On both occasions, the lasers appeared to “track” the helicopters as they moved.

A federal offense

Shining any laser at an aircraft is a federal offense. Convictions have resulted in prison terms as long as five years, fines of up to $11,000 and five years probation. Some people have been arrested because they thought the beam could not reach an aircraft. 

Why it's dangerous

A laser beam which is very small at the source expands to many inches across at longer distances. When it reaches an aircraft, imperfections in the glass of a cockpit windscreen or bubble of a helicopter cause the light to spread out even more. The pilot may experience glare, temporary flashblindness and afterimages. Since the beam cannot be held completely steady, pilots may see one or more of these bright flashes.

“Green lasers present a significant risk to flight safety, especially for helicopters working at low altitudes and aircraft taking off or landing and for boat crews operating at night,” the Coast Guard said in a statement.

How it affects missions

The affected crew members were taken off flight duty for at least 24 hours. They had to have their eyes dilated and get clearance from a doctor before flying again.

This temporary loss of flight crews has the potential to significantly affect the unit’s abilities to conduct search and rescue, training and homeland security missions. A delay during a search could also result in the death of the person or people the Coast Guard is attempting to save.

The Coast Guard is asking anyone who has information about the laser incidents to call 911 and report it.

According to the Federal Aviation Administration, reported laser incidents involving aircraft rose 931 percent between 2006 and 2013.