Unmanned planes fly without fear

Researchers from the University of Colorado are conducting flight tests and gathering scientific data with small, unmanned planes that operate in conditions unsuitable for manned aircraft.

The research team completed flight testing of the unmanned aircraft, called Aerosondes, in Barrow, Alaska in April. The team will return to Barrow in August to conduct more flight tests and to expand the scientific sampling of variables used to monitor sea ice and atmospheric conditions and to develop and refine climate models.

The Alaska flights were made in conjunction with Aerosonde Ltd and Aerosonde North America, which manufacture the aircraft.

In April, the team observed flights to test an instrument that measures surface temperatures of sea ice and the temperature variation between newly formed ice and heat coming from open water ‘leads.’ The measurements will help determine how the new ice forms and how much heat and moisture are radiating from the leads.

Judith Curry, the project’s principal investigator, said that although some engineering refinements still are needed to help the aircraft cope with the extreme low temperatures in the skies over the Arctic, the Aerosondes provide several important advantages that make them a practical alternative to existing planes for conducting Arctic science.

Curry was a principal investigator on the US National Science Foundation-supported Surface Heat Budget of the Arctic Ocean (SHEBA) project in the late 1990s.

She said that it would have been scientifically useful to have much of the information from April’s unmanned flights during SHEBA. But she noted that it simply would not have been safe for the much larger aircraft used as part of SHEBA to fly for long distances at the heights the Aerosondes reach.

‘During SHEBA we didn’t get any measurements over the new ice, it was just too dangerous,’ she said. The Aerosonde, she added, has the potential to be a much cheaper and safer alternative to conduct some very important fieldwork in the Arctic.

James Maslanik, co-principal investigator on the Aerosonde project, noted that the Aersonde has the advantages over conventional planes because of their light weight (about 13.5 kilograms, or 29 pounds), ability to fly more than 1,500 miles on a gallon of fuel, and ability to remain airborne for 24 hours.

And the Aerosonde, in many cases, is more easily customised to carry scientific instruments. ‘It takes a lot of work to get a good, research quality dataset with conventional commercial aircraft,’ said Maslanik.

The Aerosonde is also said to enhance and verify other measurements such as those taken by satellites because the plane can fly low under the cloud cover that is present in the Arctic, said Maslanik.

The relatively inexpensive planes, with their long-range and ability to hug the ground, could also be used in environmental monitoring, mapping wildlife migration routes and assisting search-and-rescue operations without risking human crews.