Trees and runways are a bad combination, but officials in Duluth, Minn., are trying to find a way for the two to safely coexist in Park Point, an area adjacent to Duluth’s Sky Harbor Airport (DYT).
The airport, located near the Wisconsin border between Superior Bay and Lake Superior, sits on 70 acres on a peninsula six nautical miles southeast of Duluth. DYT, which has been in operation since the Golden Age of aviation, has both land and water operations. It also is a Port of Entry for pilots coming into the U.S.
The trees, mostly white and red pine, make up an old growth forest located south and east of the land-side runway, which is oriented 14/32 and measures 3,050 feet. Runway 32 has a displaced threshold of 658 feet because of the trees in the approach zone.
How many trees have to be removed to bring the airport into FAA compliance depends on whom you ask. Duluth Airport Authority Director Brian Ryks says it will be 193 trees, at most, but could be as few as 43. A member of the Duluth Tree Commission put the figure closer to 800.
“If the trees are not removed, the land-side part of the airport would have to be closed since it could not be licensed if the tree obstructions remain in the approach airspace,” said Ryks, noting that there has been some mitigation, in the form of lighted obstruction poles, but the trees continue to grow, making the poles less effective.
Options under consideration are topping the trees, shifting or shortening the runway, or closing the airport.
According to the Duluth News Tribune, city council members Sharla Gardner and Kerry Gauthier have asked city officials to determine what it would cost to close the airport. Gardner noted that the community is more in favor of keeping the forest than the runway.
However, it will be the FAA that ultimately decides if the airport can be closed.
The FAA has been aware of the proximity of the trees to the flight path for some time. In 2008 the agency paid 95% of a $793,000 bill for a federal Environmental Assessment, with the airport authority picking up the remaining $40,000.
“The final Environmental Assessment will go to the Minnesota Environmental Quality Board for approval and the FAA, who has final approval authority,” said Ryks.
According to Glen Orcutt, FAA senior planner for the Minnesota Airports District office, this is not a case of airport people verses tree people.
“There is good community support for the airport and good community support for the trees,” he said. “This is a tough issue. Our job is to get all the parties to the table. Any solution needs to be long term because, at this point, the trees are just encroaching on airspace and they will continue to grow and that will deteriorate the utility of the airport.”
One of the parties taking part in the discussion is the Duluth Tree Commission.
“We got involved because there is a considerable amount of city land involved here,” said member Jim Larson. “The forest is unique. There aren’t many pine forests on sand bars, which is essentially what the area is. The peninsula is about seven miles long and mostly developed, except for the forest.”
According to Larson, 13 proposals to address the tree issue have been discussed.
“They range from not doing anything at all, which would probably lead to the airport being shut down by the FAA, to shifting the runway by a degree and a half away from the forest,” he said. “Cost and engineering play a big role in the options. One option was to take fill dirt from the bay to build the runway into the bay and away from the trees. But when we did the scoping on that we discovered that the soil in the bay is very unstable, and eventually the runway would settle so that it would have a big dip in it, so that didn’t work.”
Options that entail the cutting of a significant amount of trees are not well received, he noted.
“One alternative would have cut approximately 800 trees in the airport transition zone. That was pretty unacceptable to the members of the tree commission, as well as to the environmentalists in the community,” he said.
As this issue was going to press, a timeline for a decision had not been set.
For more information: DuluthAirport.com/Skyharbor.php