When avolcano erupted in Iceland in 2010, it filled the skies over Europe with a massive ash cloud.

From April 15-21, 2010, more than 100,000 flights were cancelled as officials scrambled to assess safety.

The closures cost the airlines an estimated $2.6 billion.

It also sticks to windshields and can interfere with other instruments.

The ash is difficult to detect and track because it is incredibly fine.

If the wind is blowing to the northwest, the ash ends up in European skies.

To test the sensor, the companies created an artificial ash cloud on October 30.

They released about a metric ton of volcanic ash collected from the 2010 eruption.

That is about 100,000 metric tons – so this test cloud was 0.00001 percent of the overall 2010 cloud.

At first, the test cloud was visible to the blind eye.

After a few minutes, it dissipated, making it difficult to spot.

This is a 300-seat passenger plane.

The larger aircraft was equipped with an AVOID sensor that was pointed towards the ash cloud.

This would help avoid massive airspace closures, such as the one in 2010.

This story originally appeared onCBSNews.com.