What is a military helicopter spraying in the U.P.?

GWINN, Mich. (WBAY) - People near Sawyer Airport are asking about a military helicopter spraying a white mist over the former air force base in Michigan's Upper Peninsula.

A Chinook helicopter creates an artificial ice cloud over Sawyer Airport in Gwynn, Michigan (Photo: Jessica Derouin)

Airport manager Duane Duray tells Action 2 News the helicopter is spraying water to create an artificial ice cloud.

An Army division that does icing certification for aircraft takes advantage of the very cold weather. It uses a Chinook helicopter equipped with a very large water tank. It sprays water through a boom behind the helicopter, and an aircraft following the helicopter flies into the mist.

Duray explained this allows for controlled testing. If the icing begins to affect the test aircraft, the pilot can fly out of the mist.

The Army has a "paying customer" that wants to test a new or redesigned aircraft and get it certified, so the division is warming up, you might say, to make sure everything is ready for the controlled tests.

Duray says the former base has been used for icing certification for years.

He isn't surprised by the phone calls, though. The Chinook is a large and powerful helicopter, and Duray says the neighbors can feel it pass overhead.